Abstract:
The mercerizing of cellulose fibers is improved by using an aqueous alkaline bath composition having as a wetting agent alkali salts of alkene sulfonic acids having 6 to 10 carbon atoms and single or double branched structures in a concentration of about 1 to 5 grams per liter of bath composition.

Description:
CROSS-REFERENCE TO A RELATED APPLICATION 
     Applicants claim priority under 35 USC 119 for application P 26 20 014.6 filed May 6, 1976, in the Patent Office of the Federal Republic of Germany. 
     BACKGROUND OF THE INVENTION 
     The field of the invention is compositions for mercerizing cellulose fibers. 
     The mercerizing of cellulose fibers is a well-known operation during textile finishing. 
     The mercerizing step imparts to the cellulose fibers increased luster, improved dyeability, higher tear strength, better moisture absorption, and higher lightfastness and weathering resistance. 
     The mercerizing process resides in treating the cellulose containing fiber material, which is under tension, with alkali solutions of a high concentration at predominantly low temperatures. 
     In order to have the mercerizing procedure take place rapidly, thus ensuring a high throughput and a satisfactory economy of the processes, the fiber must be soaked quickly and uniformly with the alkali solution. 
     Since high-percentage alkali hydroxide solutions exhibit a high surface tension, the use of wetting agents is ncessary. It has been known to add phenols and phenol derivatives to the mercerizing solution (see Lindner, &#34;Tenside-Textilhilfsmittel-Waschrohstoffe&#34; [Tensides--Auxiliary Textile Agents--Detergent Raw Materials] [1964] vol. II, pp. 1,476-1,478). The phenolates formed in the alkali solution actually are not as yet wetting agents, but they act as hydrotropic compounds and emulsifiers on the actual active agents causing the wetting effect. Such active agents are, for example, alkanesulfonates and alkyl sulfates. 
     Compositions containing phenol and phenol derivatives have only little significance nowadays due to the large amounts which must be employed (10-20 g./l.) and due to the troublesome odor, and they are no longer used, above all, because the phenols are considerably toxic to fish. 
     However, phenol-free mercerizing agents are likewise known. These are primarily alkanesulfonates and alkyl sulfates as disclosed in German Published Application No. 1,154,460, as well as mixtures thereof, as they are available in several known commercial products. These prior-art agents impart a certain wettability to the highly concentrated solutions of alkali, but this wettability is not as yet fully satisfactory. Furthermore, the solubility of the agents of the prior art in highly concentrated alkali solutions is not always adequate. 
     SUMMARY OF THE INVENTION 
     Having in mind the limitations of the prior art, it has now been discovered that these disadvantages of the prior art are overcome by using as the wetting agents the alkali salts of branched alkene sulfonic acids having not more than two branches containing 6-10 carbon atoms in aqueous alkaline baths containing 100-450 grams per liter of sodium hydroxide, potassium hydroxide and/or lithium hydroxide, in amounts of 1-5 grams of alkene sulfonate per liter of bath liquor. In particular, the alkali solutions contain 330-450 grams per liter of alkali hydroxide. 
     Preferably, alkene sulfonates which contain 7-9 carbon atoms are utilized. 
     In another preferred embodiment of the process according to the present invention, 2-3 grams of alkene sulfonate is used per liter of bath liquor. Especially preferred is the use of the alkali salts of alkene sulfonic acids prepared from tripropylene, 2-ethylhexene, 3-methyl-2-heptene, 3-methyl-3-heptene, or mixtures thereof. 
     It is advantageous to employ, in addition to the alkene sulfonate of this invention, products which are effective as hydrotropic agents, emulsifiers, defrothers, etc. 
     Under practical conditions, for example, such products are alcohols and alcohol derivatives, carboxylic acids, amines, etc. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The figures of the drawings appended hereto are graphical representations of data taken from the tables which follow, wherein: 
     FIG. 1 is an X-Y plot of the data for percentage shrinkage per second based on initial yarn length for the present invention versus the prior art as taken from Tables 1-4. 
     FIG. 2 is an X-Y plot of the data for percentage shrinkage per second, based on final shrinkage for the present invention versus the prior art as taken from Tables 5-8. 
     FIG. 3 is an X-Y plot of the data for percentage shrinkage per second, based on final shrinkage for the present invention versus the prior art as taken from Table 7; 
     FIG. 4 shows X-Y plots of the shrinkage in mm per second and percentage shrinkage per second for the present invention at the beginning and after three months; and 
     FIG. 5 shows X-Y plots of the shrinkage in mm per second and percentage shrinkage per second for the present invention at the beginning and after further concentration of the alkali solution. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The steps according to the present invention provide the surprising commercial advantage, as compared to the state of the art, of appreciably raising the wettability of highly concentrated alkali solutions, as can be derived from Tables 1-8, especially from Tables 3,4,7, and 8 which follow. 
     The shrinkage of the yarn length and/or the final shrinkage is markedly higher with the use of high alkali solution concentrations after the treatment of the present invention than with the use of the agents of the prior art. 
     Tables 1-8 also show that the teaching of the present invention is critical to a high degree: unbranched sulfonates, as well as those having more than two branchings and sulfonates of more than 10 carbon atoms, do not exhibit the desired effect. 
     As can be seen from FIG. 4, the agents to be used in accordance with the invention effect, as required in practice, a very good alkali resistance over longer periods of time without a reduction in the wetting capability of the alkali solution, i.e. they are absolutely resistant to hydrolysis. 
     FIG. 5 shows that the wetting agents to be used in accordance with the present invention make it possible to concentrate (evaporate) the alkali solution several times, since they are, as desired, not steam-volatile, but they are resistant against boiling alkali solutions. This property displayed by the wetting agents is absolutely required for the wet mercerization. 
     Additionally, the compounds to be employed according to the present invention, show an excellent dispersing and dirt-loosening capacity, which has an advantageous effect above all during the treatment with the alkali solution and during the mercerizing of raw cotton. 
     The agents to be utilized in accordance with the present invention, furthermore, have the great advantage over the customary mixtures of the prior art that they are fully effective already without adding auxiliary agents; in other words, it is possible according to the present invention to operate with absolute substance uniformity. As a consequence, it is impossible for the lye to be nonuniformly depleted of wetting agents and auxiliary agents (due to absorption processes which are hard to control). 
     A significant advantage of the agents to be used in accordance with the present invention, is, finally, that they can be manufactured from readily accessible, inexpensive raw materials in an economical manner. 
     The alkene sulfonates to be used in accordance with the present invention are produced from branched alkenes having 1 to 2 branches and containing 6-10 carbon atoms. Examples of branched olefins having 1 to 2 branches and 1 to 3 carbon atoms per branch as starting materials are: tripropylene, 2-ethylhexene, 3-methyl-2-heptene, 
     These starting materials can be reacted by following one of the conventional methods with SO 3  and/or complexed SO 3  to alkene sulfonates. A detailed description of the manufacturing possibilities is found in &#34;Tenside&#34; [Tensides] 4 (1967): 286 et seq., author: F. Puschel. 
     The production of tripropylene is described, for example, in: Winnacker and Kuchler, &#34;Chem. Technologie&#34; [Chemical Technology] 3: Org. Technology I, p. 722 (1959), Carl Hauser publishers, Munich. 
     The following description relates to several specific examples for the production of alkene sulfonates to be employed according to the present invention. 
     SULFONATION WITH COMPLEXED SULFUR TRIOXIDE 
     An agitator-equipped flask is charged with 2 moles of 2-ethyl-1-hexene and 500 ml. of dichloroethane and at 30°-35° C. a SO 3  dioxane complex (2.3 moles of SO 3  /300 ml. of dioxane) is added in incremental portions within 45 minutes. After an additional agitating period of 41/2 hours, the reaction product is freed of solvent at 40° C. by means of a water-jet aspirator and thereafter neutralized with sodium hydroxide solution. Residues of solvent are removed by a brief cursory distilling step. The slightly colored sulfonate solution, which still contains minor amounts of an inorganic salt, can be made of a lighter tint, if desired, with hydrogen peroxide up to an iodine color number of 1 (based on a 5% solution). Yield: 87%. 
     SULFONATION WITH COMPLEX SULFUR TRIOXIDE 
     An agitator-equipped flask is charged with 2 moles of a mixture of 30% 2-ethyl-1-hexene, 44% 3-methyl-2-heptene, and 26% 3-methyl-3-heptene, dissolved in 500 ml. of dichloroethane. At 30° C., a SO 3  -dioxane complex (2 moles of SO 3  /250 ml. of dioxane) is added thereto in incremental portions within 50 minutes. After an additional agitation time of 41/2 hours, the charge is neutralized. The aqueous phase is separated, and residues of solvent are removed by a brief cursory distillation. Iodine color number (based on a 5% solution): 4.7; Yield: 92%. 
     SULFONATION WITH FREE SULFUR TRIOXIDE 
     An agitator-equipped flask is charged with 2 moles of 2-ethyl-1-hexene and heated to 40° C. Thereafter, a mixture of 2 moles of SO 3  in 2,000 ml. of dichloroethane is added dropwise within 2 hours. After a post reaction time of 4 hours, the charge is neutralized, the aqueous phase is separated and freed of residual amounts of solvent by cursory distillation. Iodine color number of a 5% solution: 2.4; Yield 90%. 
     Specific examples of the alkali salts of alkene sulfonic acids useful in the present invention include the alkene sulfonate sodium salt from 2-ethyl-1-hexene, the alkene sulfonate sodium salt from tripropylene, the alkene sulfonate sodium salt from 3-methyl-2-heptene, the alkene sulfonate sodium salt from 3-methyl-3-heptene, the alkene sulfonate potassium salt from 2-ethyl-1-hexene, the alkene sulfonate potassium salt from tripropylene, the alkene sulfonate potassium salt from 3-methyl-2-heptene, the alkene sulfonate potassium salt from 3-methyl-3-heptene, the alkene sulfonate lithium salt from 2-ethyl-1-hexene, the alkene sulfonate lithium salt from tripropylene, the alkene sulfonate lithium salt from 3-methyl-2-heptene, the alkene sulfonate lithium salt from 3-methyl-3-heptene. 
     The agents to be used according to the present invention are intended primarily for lye and mercerizing solutions. 
     The wetting capability of the olefin sulfonates of the present invention was tested in a modified device according to Hintzmann described in &#34;Melliand Textilbericht&#34; [Melliand Textile Report] (1973) 10: 1,112 and in German Industrial Standard DIN 53,987 (August 1971). 
     The operation was conducted with a lye volume of 450° cc. and at a lye temperature of 20° C. The raw cotton yarn (Nm 34) utilized had, double-scutched, a hank length of 25 cm. and a weight of (1.0±0.1) grams. The yarn hanks which were stored immediately prior to testing for 24 hours in a normal climate according to 20/65 DIN 50 014 had a load exerted thereon of respectively 20.0 grams. 
     The effectiveness of the wetting ability of the products according to the present invention in the various test lyes was determined by the shrinking velocity of the thustreated cotton yarn. The longitudinal shrinkage was measured after respectively 30, 60, 90, 120, and 150 seconds of treatment, corresponding to the requirement for a short-term treatment posed under practical conditions. The reference value is the final shrinkage obtained after a treatment period of 10 minutes. 
     The shrinkage values obtained during the testing process are indicated by tables and graphs. For comparison purposes, the tests included α-olefin sulfonates made of diisobutene, 1-hexene, 1-octene, and 1-dodecene, 2-ethylhexyl sulfate, and three commercial lye and mercerizing wetting agents. 
     The test lyes employed contained in: 
     
         ______________________________________Lyes 1a-11a      270 g. of sodium hydroxide per literLyes 1b-11b      300 g. of sodium hydroxide per literLyes 1c-11c      330 g. of sodium hydroxide per literLyes 1d-11d      360 g. of sodium hydroxide per liter______________________________________ 
    
     and the anhydrous products set forth below: 
     
         ______________________________________Lyes 1a-1d 2 g.     of olefin sulfonate Na salt               from 2-ethyl-1-hexene (accord-               ing to the invention)Lyes 2a-2d 2 g.     of olefin sulfonate Na salt               from tripropylene (according               to the invention)Lyes 3a-3d 2 g.     of olefin sulfonate Na salt               from diisobutene (for comparison)Lyes 4a-4d 2 g.     of olefin sulfonate Na salt               from 1-hexene (for comparison)Lyes 5a-5d 2 g.     of olefin sulfonate Na salt               from 1-octene (for comparison)Lyes 6a-6d 2 g.     of olefin sulfonate Na salt               from 1-dodecene (for comparison)Lyes 7a-7d 2 g.     of 2-ethylhexyl sulfate Na salt               (for comparison)Lyes 8a-8d 1.8 g    of olefin sulfonate Na salt               from 2-ethyl-1-hexene      +0.2 g.  of n-hexanol (according to the               invention)Lyes 9a-9d 2 g.     of commercial product A               (prior art)Lyes 10a-10d      2 g.     of commercial product B               (prior art)Lyes 11a-11d      2 g.     of commercial product C               (prior art)______________________________________ 
    
     Commercial products A, B, and C, according to data provided by the manufacturers, are mixtures of anionic surfactants (sulfates and/or alkanesulfonates) and auxiliary agents. 
     
                                           TABLE 1__________________________________________________________________________Lye(270 g. of NaOH per Liter)Shrinkage of the Yarn Lengthin mm./sec.                in %/sec.0      30 60 90 120              150                 10 Min.                      30 60 90 Remarks__________________________________________________________________________1a  250  180     169        167           166              166                 165  28.0                         32.4                            33.1                               Acc. to Invention2a  250  182     178        177           176              175                 174  27.2                         28.7                            29.2                               Acc. to Invention3a-6a    Ineffective and/or Immeasureable                      -- -- -- For Comparison 7a 250  233     215        204           195              191                 181  6.8                         14.0                            18.3                               For Comparison 8a 250  172     166        165           164              164                 164  31.2                         33.6                            34.0                               Acc. to Invention 9a 250  191     179        172           169              167                 165  23.6                         28.4                            31.2                               Prior Art10a 250  229     199        178           170              168                 166  8.4                         20.4                            28.8                               Prior Art11a 250  176     170        170           169              169                 167  29.6                         32.0                            32.0                               Prior Art__________________________________________________________________________ 
    
     
                                           Table 2__________________________________________________________________________Lye300 g. of NaOH per Liter)Shrinking of the Yarn Lengthin mm./sec.                in %/sec.0      30 60 90 120              150                 10 Min.                      30 60 90 Remarks__________________________________________________________________________1b  250  178     175        174           173              173                 173  28.8                         30.0                            30.4                               Acc. to Invention2b  250  179     172        170           169              169                 168  28.4                         31.2                            32.0                               Acc. to Invention3b-7b    Ineffective and/or Immeasureable                      -- -- -- For Comparison 8b 250  176     171        169           169              169                 169  29.6                         31.6                            32.4                               Acc. to Invention 9b 250  189     174        172           171              171                 170  24.4                         30.4                            31.2                               Prior Art10b 250  225     192        181           174              171                 169  10.0                         23.2                            27.6                               Prior Art11b 250  181     172        171           170              170                 168  27.6                         31.2                            32.0                               Prior Art__________________________________________________________________________ 
    
     
                                           Table 3__________________________________________________________________________Lye(330 g. of NaOH per Liter)Shrinkage of the Yarn Lengthin mm./sec.                in %/sec.0      30 60 90 120              150                 10 Min.                      30 60 90 Remarks__________________________________________________________________________1c  250  198     177        175           174              173                 170  20.8                         29.2                            30.0                               Acc. to Invention2c  250  192     182        174           170              169                 167  23.2                         27.2                            30.4                               Acc. to Invention3c-7c    Ineffective and/or Immeasureable                      -- -- -- For Comparison 8c 250  191     172        170           169              169                 167  23.6                         30.4                            31.2                               Acc. to Invention 9c 250  220     199        188           181              178                 167  12.0                         20.3                            24.8                               Prior Art10c 250  241     230        216           200              191                 171  3.6                         8.0                            13.7                               Prior Art11c 250  232     201        179           173              171                 165  7.2                         19.6                            29.4                               Prior Art__________________________________________________________________________ 
    
     
                                           TABLE 4__________________________________________________________________________Lye(360 g. of NaOH per Liter)Shrinkage of the Yarn Lengthin mm./sec.                in %/sec.0      30 60 90 120              150                 10 Min.                      30 60 90 Remarks__________________________________________________________________________1d  250  203     178        173           172              172                 171  18.8                         28.7                            30.7                               Acc. to Invention2d  250  229     190        177           172              170                 168  8.4                         24.1                            29.2                               Acc. to Invention3d-7d    Ineffective and/or immeasureable                      -- -- -- For Comparison 8d 250  197     171        167           166              165                 164  21.2                         31.6                            33.2                               Acc. to Invention 9d 250  225     206        193           188              185                 169  10.0                         17.6                            22.8                               Prior Art10d 250  242     230        211           198              186                 167  3.2                         8.0                            15.6                               Prior Art11d Failed, immeasureable  -- -- -- Prior Art__________________________________________________________________________ 
    
     
                       TABLE 5______________________________________Lye(270 g. of NaOH per Liter)               Shrinkage in %Shrinkage in mm./sec.               (Based on Final          10   Shrinkage)30     60    90    120  150  Min. 30   60   90   Remarks______________________________________                                              Acc.1a   70    81    83  84   84   85   82.3 95.3 97.5 to In-                                              vention                                              Acc.2a   68    72    73  74   74   76   89.8 94.7 95.9 to In-                                              vention                                              For3a-  Ineffective and/or sparingly                   --     --   --   Com-6a   soluble                             parison                                              For7a   17    35    46  55   59   69   24.6 50.8 66.4 Com-                                              parison                                              Acc.8a   78    84    85  86   86   86   90.7 97.7 97.7 to In-                                              vention9a   59    71    78  81   83   85   69.3 83.5 91.7 Prior                                              Art10a  21    51    72  80   82   84   25.0 60.7 85.5 Prior                                              Art11a  74    80    81  82   83   85   87.2 94.0 95.3 Prior                                              Art______________________________________ 
    
     
                       TABLE 6______________________________________Lye(300 g. of NaOH per Liter)               Shrinkage in %Shrinkage in mm./sec.               (Based on Final          10   Shrinkage)30     60    90    120  150  Min. 30   60   90   Remarks______________________________________                                              Acc.1b   72    75    76  77   77   78   92.4 96.3 97.5 to In-                                              vention                                              Acc.2b   71    78    80  81   81   82   86.6 93.8 97.5 to In-                                              vention                                              For3b-  Ineffective and/or sparingly                   --     --   --   Com-7b   soluble                             parison                                               Acc.8b   74    79    81  81   81   81   91.4 98.2 100.0                                              to In-                                              vention9b   61    76    78  79   79   80   76.3 95.3  97.5                                              Prior                                              Art10b  25    58    69  76   79   83   30.2 70.0  83.1                                              Prior                                              Art11b  69    78    79  80   80   82   83.9 95.0  96.2                                              Prior                                              Art______________________________________ 
    
     
                       TABLE 7______________________________________Lye(330 g. of NaOH per Liter)               Shrinkage in %Shrinkage in mm./sec.               (Based on Final          10   Shrinkage)30     60    90    120  150  Min. 30   60   90   Remarks______________________________________                                              Acc.1c   52    73    75  76   77   80   65.1 91.3 93.7 to In-                                              vention                                              Acc.2c   58    68    76  80   81   83   70.1 81.7 91.6 to In-                                              vention                                              For3c-  Ineffective and/or sparingly                   --     --   --    Com-7c   soluble                             parison                                              Acc.8c   59    76    78  79   79   81   72.8 93.9 96.3 to In-                                              vention9c   30    51    62  69   72   83   36.2 61.5 74.7 Prior                                              Art10c  9     20    34  50   59   81   11.1 24.7 41.8 Prior                                              Art11c  18    49    71  77   79   85   21.3 57.9 83.7 Prior                                              Art______________________________________ 
    
     
                       TABLE 8______________________________________Lye(360 g. of NaOH per Liter)               Shrinkage in %Shrinkage in mm./sec.               (Based on Final          10   Shrinkage)30     60    90    120  150  Min. 30   60   90   Remarks______________________________________                                              Acc.1d   47    72    77  78   78   79   59.5 91.1 97.3 to In-                                              vention                                              Acc.2d   31    60    73  78   80   82   37.9 73.2 89.0 to In-                                              vention                                              For3d-  Ineffective and/or sparingly                   --     --   --    Com-7d   soluble                             parison                                              Acc.8d   53    79    83  84   85   86   61.5 92.0 96.5 to In-                                              vention9d   25    44    57  62   65   81   31.0 54.3 70.5 Prior                                              Art10d  8     20    39  52   64   83   9.6  24.1 47.0 Prior                                              Art11d  Failed, immeasureable                   --     --   --   Prior                                    Art______________________________________