US3409462A - Process for treating textiles and textiles treated by such process - Google Patents

Description

United States Patent ice 3,409,462 PROCESS FOR TREATING TEXTILES AND TEXTILES TREATED BY SUCH PROCESS Heinz Enders, Stadthergen, Augsburg, and Giiuter Pusch,

Leitersllofen, Augsburg, Germany, assignors to Chemische Fabrik Pfersee G.m.b.H., Augsburg, Germany,

a firm of Germany N0 Drawing. Filed Nov. 20, 1964, Ser. No. 423,619

Claims priority, application Germany, Dec. 21, 1963, C 31,733; Jan. 21, 1964, 0 31,929 3 Claims. (Cl. 117119.6)

ABSTRACT OF THE DISCLOSURE The wet and dry crease resistance of textiles containing predominantly natural or regenerated cellulose fibers is improved by a process in accordance with which the textile fabric is impregnated with an aqueous bath containing methylol compounds of cyclic alkylene ureas or cyclic oxyalkylene ureas and a strong acid. Then the superfluous bath is removed in the usual manner, the fabric is dried to a moisture content ranging between 4% and 30%, the humid fabric is stored at about room temperature, the fabric is rinsed and then the neutral fabric is subjected to a final drying.

This invention relates to a process for treating textiles and to textiles treated by such process and refers more particularly to a process for treating textiles consisting entirely of, or containing for the major part, natural or regenerated cellulose fibers.

It is known in prior art to treat textiles having cellulose fibers with so-called reactant resins, such as methylol compounds of alkylene ureas, along with acidly acting hardening means in an aqueous solution and after drying to subject them to condensation by heating to temperatures over 100 C..Textiles treated in this manner acquire the property of resisting wrinkles in dry state and, in addition, they acquire to a limited extent the capacity of resisting wrinkles when wet. However, mechanical properties of the material suffers as the result of this process, the material becomes brittle and the abrasion resist ance is greatly diminished. When, as has been sug gested, strong mineral salts are used as hardening means in this process, the material acquires a somewhat better wet crease resistance, but the mechanical properties of the fibers suifer thereby to an even greater extent.

According to another known process cellulose textiles are impregnated with a solution of alkylene ureas and acid, amounts of 1 to N; then after removal of excess bath but while the fibers are still in a highly swollen state, the textiles are rolled up and are allowed to stand for some time at room temperature; then the acid is removed by neutralization and rinsing and the goods are finally dried. This increases the wet crease angles of the goods, but not the dry crease angles. The so-called Monsanto picture (surface crease resistant picture after washing and drying without ironing) is moderate.

An object of the present invention is to improve these prior art processes and the properties of the materials treated by these processes.

Another object is the provision of a process which will impart to a treated fabric a very good ironing condition, so that the fabric will exhibit a good Monsanto picture, as well as high dry and wet crease angles.

A further object is the provision of a process which will improve the above-stated conditions of a fabric to a greater extent than was possible heretofore, whereby as the result of this process the mechanical properties of the fibers suffer considerably less than is the case in prior art processes.

3,409,462 Patented Nov. 5, 1968 Other objects of the present invention will become apparent in the course of the following specification.

In the accomplishment of the objects of the present invention it was found desirable to treat the textile material with a bath containing methylol compounds of cyclic alkylene ureas wherein one or two H-atoms upon different carbons can be replaced by hydroxyl groups or the ethers of such methylol compounds with low monovalent alcohols, as well as strong acids in amounts of about 0.1% to 6% of the weight of the bath; after the removal of the surplus bath in the usual manner the material is dried to a moisture content of 4% to 30%, preferably 7% to 20% of the weight of the material. Then the material is rolled up and is allowed to stand for a lengthy time period with as little change as possible of its moisture content; preferably the material is allowed to stand at room temperature for from about 4 hours to 30 hours, while the time period is correspondingly shortened when the temperature is somewhat higher. Then the material is washed, possibly with the addition of neutralizing compounds, rinsed and dried.

It was found that a textile material treated by the process of the present invention has smaller losses in tear and abrasion resistance than materials treated by prior art process. Chlorine retention when washing with chlorinebleaching agents does not take place and a white material does not become yellowish after many washes. The positive qualities of a fabric treated in accordance with the process of the present invention are improved to a great extent, as will be set forth in detail hereinafter.

Reference should be made to another prior art process in accordance with which textiles after being treated with a substance which cross links with itself or with the fibers at pH-values of under 2 and while having at most 12% moisture, are allowed to stand for a certain time in a rolled up condition at temperatures of l5-60 C. and are then dried after neutralization and rinsing. Apparentlv compounds of different types can be used as crosslinking means, including methylol compounds of alkylene ureas. The moisture of 3 to 12% remaining in the textile material is provided by applying to the dry material either an emulsion or a solution of the cross linking means and hardening means in an organic solvent. These organic solutions or emulsions contain water in such amounts that the textile material receives the desired amount of moisture. A drawback of this prior art process is that it requires a precise dosage and the use of special apparatus to maintain the moisture content of the material completely uniform at all times.

According to another variant of the last-mentioned prior art process the fabric is impregnated with an aqueous solution of the cross linking substance in the usual manner, the excess is removed and the fabric dried; then in a separate operational step of the process, the hardening substance is applied in an organic solution or emulsion with the addition of an amount of water which will impart to the fabric a moisture content of 3-12%.

This process has the drawbacks of requiring an addition-al process step, special apparatus is required for work with organic solvents and a uniform application of the hardening means and water is difficult.

According to both variations of the prior art process the fabric must be first completely dried and then a precisely dosed amount of water must be applied to it. An important disadvantage is the use of organic solvents which are expensive and cannot 'be regenerated in this prior art process.

An advantage of the process of the present invention is that it eliminates all these complicated process steps required in prior art. A further advantage is, that no organic solvents are to be used.

Strong acids which are suitable for the process of the present invention are muriatic acid, sulphuric acid and nitric acid or oxalic acid, while phosphoric acid is less suitable due to its low acidity.

The treating baths of the present invention contain about 6% to 25% of 100% methylol compounds or their ethers. It is possible to replace the methylol compounds up to a maximum of 50% of their weight by nitrogen-free formaldehyde reaction products with monoor poly-valent alcohols up to 4 C-atoms. These nitrogenfree reaction products may be made by heating waterfree formaldehyde, especially paraformaldehyde, with the alcohol in presence of a strongly acidic catalyst in a proportion of 1 mol of formaldehyde for each equivalent of hydroxy groups.

The process of the present invention is suitable for fabrics of natural and/or regenerated cellulose fibers. The cellulose fibers can appear as mixtures with other fibers, but the cellulose fibers must be predominant.

Methylol compounds of cyclic alkylene ureas suitable for the present invention are those of ethylene urea, propylene urea, or dioxyethylene urea, oxypropylene urea, as well as bicyclic ureas, such as acetylene diurea. These methylol compounds can be alkoxylated with low monovalent alcohols, such as methanol, ethanol or propanols.

For the treatment of undyed textiles which contain preponderantly natural cellulose fibers, methylol compounds of propylene or oxypropylene urea are preferred; for the treatment of dyed textiles methylol compounds of dioxyethylene urea are preferably used. For such textiles the amount of strong acid should be preferably 0.2% to 3.5%. The drying is preferably carried out up to a residual moisture of 7% to For the treatment of textiles which contain a preponderance of regenerated cellulose fibers it is advantageous to use methylol compounds of ethylene or dioxyethylene ureas or acetylene diurea With an acid concentration in the bath of preferably 2% to 5%. The drying should be carried out specifically to a residual moisture content of 8% to The following examples are given by way of exemplification only:

Example 1 A mercerized bleached cotton poplin having a weight of 128 gr. per sq. m. was impregnated upon a foulard with a bath consisting of 35% of a 50% aqueous dimethylol propylene urea solution, 1.2% of a concentrated (36%) muriatic acid and 63.8% water; the material was squeezed up to a bath content of 70%, then it was dried upon a stretch frame with hot air having 110 C.

up to a residual moisture of 9%. The material was smoothly wound up while having this residual moisture and was allowed to stand for 18 hours at a temperature of 20 C. Thereupon it was promptly washed, neutralized with 2 gr./l. soda, rinsed and dried.

The cotton fabric treated in this manner has the following technological data:

Crease angle wet, 158

Crease angle dry, 127

Monsanto crease picture after 5 boiling washes with centrifugal runs 5 A gay-colored printed cotton creton was impregnated with a bath consisting of of a 50% dimethylol-S- hydroxypropylene urea solution, 1.2% concentrated nitric acid and 73.8% water; the material was squeezed to 65% moisture and thereupon was dried to a residual moisture of 12%. It was then wound up, allowed to stand for one hour at a temperature of 40 C. and thereupon washed, neutralized anddried.

This material in addition to-having good wet and dry crease resistance, has avery small inclination to brittleness, best possible resistance to chlorine and" there is no diminution of the light resistance of the dyes.

Example 3.

A reactively dyed spun vrayon twill having a weight of 180 gr. per sq. rn. was impregnated with a bath consisting of 20% of an approximately 100% dimethyloldihydroxyethylene urea, 3% of a 98% sulphuric acid and 27% water; the material was squeezed to about 90% moisture and was dried upon a stretch frame to a residual moisture of about 16%. It was then smoothly wound and allowed to stand at room temperature for 20 hours. Finally it was washed upon a wide washing machine, neutralized and dried.

Example 4 A white spun rayon muslin was impregnated with a solution consisting of 30% of a 50% tetramethylolacetylene diurea, 6% of a hexamethylol melamine resin alkoxylated with methyl alcohol, 2.5% of a 36% muriatic acid and 61.5% water; moisture was removed by suction to 100% content and then it was dried to a residual moisture of 20%. Thereupon it was smoothly wound, allowed to stand at room temperature for 8 hours, washed and dried.

The muslin treated in this manner has good dry and wet crease angles and a pleasant full feel, and its abrasion resistance is well preserved.

Example 5 A dyed spun rayon twill containing 33% polyester staple fibers in the warp was impregnated with a bath consisting of 15% of an about 100% dimethylol-dihydroxyethylene urea, 5% of a glycol formaldehyde halfacetal, 5% of an 89% sulphuric acid and 75% water; the material was squeezed to about bath content and then dried in a stretch frame to a residual moisture of 8%. It was then smoothly rolled up and was allowed to stand at room temperature for 20 hours; finally without any pro-heating it was neutralized upon a wide washing machine and dried.

The fabric treated in this manner has excellent dry and wet crease angles, a pleasant feel, good dimension stability and a good Monsanto wash-and-wear note.

Example 6 A mercerized dyed cotton gaberdine having a mixture of 33% polyester-staple fibers, 'was impregnated with a bath consisting of 30% of a 50% aqueous dimethylolpropylene urea solution, 10% of a 50% aqueous dimethylol-dihydroxyethylene urea solution, 3.5% oxalic acid and 56.5% water.

The material was squeezed to a bath content of 60% and dried upon the usual drying stretch frame to a residual moisture content of 5%; then it was smoothly rolled up, allowed to stand for 16 hours at 25 C. and then washed as well as neutralized, rinsed and dried.

The mixture cotton polyester gaberdine treated in this manner has good wash-and-wear properties at high wet crease angles and, in addition, has a good dry crease resistance. The abrasion resistance is barely diminished.

It is apparent that the examples set forth above have been given solely by way of illustration and not by way of limitation and that they are capable of many variations and modifications within the scope of the present invention. All such variations and modifications are to be included within the scope of the present invention.

What is claimed is:

1. A process for treating textiles containing at least predominantly natural or regenerated cellulose fibers, comprising the steps of impregnating a textile material with an aqueous bath containing about 6% to 25% methylol compounds selected from the class consisting of cyclic alkylene ureas and cyclic oxyalkylene ureas, and substantially from 0.1% to 6% of a strong acid, removing the superfluous bath from the material, drying the material until it has a moisture content ranging between 4% and 30%, winding it into a roll and allowing it to stand in this condition for substantially 4 to 30 hours at a low temperature, and then rinsing and drying the material.

2. A process in accordance with claim 1, wherein the material is dried to a moisture content of 7% to 20%.

3. A process in accordance with claim 1, wherein the aqueous bath contains ethers of said methylol compounds with low monovalent alcohols.

References Cited UNITED STATES PATENTS Spangler et a1. 117-161 Burks 117-145 Williams 117-139.4 Torke et al. 117-145 Nuessle et a1 117-139.4 Canter 117-143 Reinhardt et a1. 117-139.4 Enders 117-161 Van Loo et al. 117-139.4 Poon 117-139.4 X

15 WILLIAM D. MARTIN, Primary Examiner. M. R. P. PERRONE, JR., Assistant Examiner.