US2927840A - Process for the treatment of fibrous materials - Google Patents

Description

United States emo PROCESS FOR THE TREATMENT OF FIBROUS. MATERIALS Karl Dithmar and Elfriede Naujoks, Frankfurt am Main,

Germany, assignors to Deutsche Goldund' Silber- Scheideanstalt Germany No Drawing. Application June 28, 1956 Serial No. 594,381

' Claims priority,application Germany July 8, 1955 9-Claims. (Cl. 8-111) The present invention relates to improvements in the treatment of natural or synthetic fibers and textiles produced therefrom with peroxidic compounds, such as hyf drogen'peroxide, perborates, percarbonates and perpyro- I '70" 'C.,"unless boilers are used.

:9 'It is-therefore an object of the invention to provide a manner. in which peroxidic compositions can be rendered more effective in the treatment of textiles at temperatures substantially lower than the boiling point of the aqueous solutions employed.

According to the invention, it was unexpectedly found that the presence of organic compounds containing one or more nitrile groups accelerate the liberation of oxygen from substances containing active oxygen (peroxidic compounds) and to increase the cleaning action to such an extent that the same cleaning action is obtained at, for example, 60 C., as in the usual boil 'washes. :Therefore, carrying out the invention, nitriles are added to the washing liquid containing peroxidic compounds. Very good results are obtained with stoichiometric portions of the nitrilesand the peroxidic compounds, that is, 1 mol mononitrile per mol of peroxide. Diand polynitriles as a result havean increased action corresponding to the number of nitrile groups contained therein. However, the invention is not limited to this molar relationship, as the regulation of the washing velocity must be more suited to the practical requirements than to the chemical requirements.

Organic nitriles, whether mono-, dior polynitriles,

are suitable for the purposes of the invention, as long as they still can be dissolved or suspended in water and are not absolutely insoluble. They can be of aliphatic, aromatic," aliphatic-aromatic, or hydroaromatic nature and the C chains or rings of such compounds may be interrupted by heteroatoms. tained with organic nitriles. containing a plurality of nitrile groups which are not separated too far from'each "other. The activity increases to a certain extent with increase in nitrile group content. On the other hand, cy-anides, that is, salts of hydrocyanic acid, are not suitable, as they tend to discolor textiles.

. I n contrast to such known processes in which the degpmposition ot peroxidic compounds is accelerated with vormals Roessler, Frankfurtam Main, 7

introduced into bleaching practices.

Patented Mar. 8, 1960 the catalytic damage of textiles observed in peroxide baths containing metal compounds is completely avoided. For this reason, metal compounds were never successfully Furthermore, such metal compound accelerators usually led to soiling of the textiles rather than an improved washing elfect.

The following organic nitrile compounds have been found particularly elfective as additions in aqueous washing and bleaching baths containing peroxidic compounds:

Malonitrile Malonic acid amide nitrile Ethylene dinitrile Ethylene diamino tetracetic acid nitrile Tetramethylene dinitrile Nitrilotriacetic acid nitrile Benzonitrile Dimethyl-diamino-succinic acid dinitrile Methylene-bis-imino acetonitrile I Phthalonitrile Terephthalic acid'nitrile The activation of the peroxidic compounds in bleaching and washing baths according to the invention is obtained even in the presence of the usual stabilizers, such as sodium pyrophosphate, sodium silicate or mag nesium'silicate and the like. Also, soaps, wetting agents and chemicals which regulate the pH of the baths can be present. Furthermore, it is also advantageous to .employfiber protection agents in combination therewith.

The components indicated can, if desired, be combined in a washing powder ready for use. The following examples will serve to illustrate several modifications according to the invention:

Example 1 An aqueous washing bath was prepared which, per

7 liter, contained the following composition:

The best results are obmetal salts or organic metal compounds, the present in- I. vention the advantage that in the absence of metals Knitted goods washed in the 10 g. sodium soap 2 g. sodium pyrophosphate 0.7 g..sodium perborate 0.1 g. malonitrile Soiled cotton underwear was washed in such bath at 60 C. with moderate movement. The ratio of underwear to bath was 1:20. After 1 hour, a' washing action was achieved which corresponded to that achieved with a boil wash of'the same duration (without the malonitrile) in which the bath was slowly heated to the boiling point. same way exhibited the same whiteness grade. 7

Example 2 Cotton nettle cloth soiled with tomato juice was treated in the following washing bath at 6 0 C.:

Per liter- 10 g. sodium soap .2 g. sodium pyrophosphate 0.5 g. sodium perborate 0.3. g. malonic acid amide nitrile A :The active oxygen content of the activated bath ae- V cording to the invention diminished approximately in the same manner as in theboil wash, as can be seen from the following table for the indicated baths, each having an initial active oxygen content of 0.056g. 100%) per liter.

Active oxygen content of bath after- Bath 30 min. 60 min. 120 min.

Percent Percent Percent (a) Activated bath at 60 C 45 31 17 (b) inactivated bath boil wash- 62 35 18 (c) Unactivated bath at 60 C... 90 8G 79 Example 3 A regenerated cellulose staple fiber fabric which was soiled with cherry juice was treated at 65 C. for two hours with a fabric to bath ratio of 1:20 in the following wash bath:

Per liter- 10 g. Marseilles soap 2 g. sodium pyrophosphate 2 g. sodium perborate 0.3 g. ethylene dinitrile As a comparison, the same soiled fabric was given a boil wash in a bath of the same composition, but omitting the ethylene dinitrile.

The original activated oxygen content of 0.22 g. of the baths used in both washes diminished in the same manner, as can be seen from the following table:

The soil removed in the activated bath at 65 C. was as good as in the boil wash.

Example 4 Active oxygen containing substances.

Stabilizer.

3.0 g. hydrogen peroxide 35%---" 5g. sodium perborate-..- 1:5 g. water glass 01 g. magnesium sulfa hydrogen peroxid" Active oxygencontaining substances.

: g. SOdi'liXIl plerboratet, 1.5 g. we or g ass .1 g. magnesium sulfate.-." Stablhzer' 0.3 g. N-pheny1bigua-nide Protective agent.

Both bleaches were carried out at 85 C. and with bath (a), a full white was achieved in 1 hour whereas, with bath (b), a full white was not achieved until after The pH values of the baths were as follows:

(a) 9.4 at start and 9.1 at the end (b) 9.6 at start and 9.3 at the end The action of the fiber protective agent which was present in the bath was not diminished by the presence of the activator, as the loss in strength of the Perlon was only 5% despite a 2 hours peroxide bleach.

Example 5 The nitriles according to the invention are also suited for the activation of finished packed powdered perborate washing compositions. While they promote the liberation of oxygen when the washing compositions containing them are dissolved in water they do not cause a. decomposition of the perborate in the dry compositions.

The stability of the following dry washing powder compositions was, observed over a period of ten months:

Soap shavings (85%) 150 Sodium pyrophosphate 40 Sodium perborate I0 Nitrilotriacetic acid nitrile 4 On the day of production, such composition contained 0.55% of active oxygen and after 10 months storage it still was 0.55%.

6. Soap shavings (85%) 150 Sodium pyrophosphate 40 Sodium perborate l0 Ethylene diaminotetraacetic acid nitrile 4 The composition also as produced contained 0.55% of active oxygen and after 10 months storage it was still 0.54%, so that the stability of the active oxygen in the dry state was not diminished to any substantial extent.

On the other hand, the cleavage of the active oxygen in aqueous wash baths at C. was substantially accelerated, as can be clearly seen from the following table in which the active oxygen content of washing baths containing compositions (a) and (b) were compared with that of a bath (0) of the same composition but omitting the organic nitrile accelerator. In each instance, the bath originally contained 0.56 g./l. of active oxygen. Of course, the smaller the percentage of active oxygen remaining in the bath the greater the activation occurring.

two hours.

The liberation of the oxygen and the bleach was ac- 30 60mm 120 celerated by the presence of the activator, as can be 65 seen from the following table: (0) gi; 32 o a) so 40 14 Active oxygen content'of (b) n 37 27 u bathatter- Bath 30 45 P The pH values of the baths at the beginning of the I tests were above 9.7 and at the end about 9.3. The withmflvflmmmmum 'f; P 5. acceleration of the oxygen liberation in the baths conwithout act!vator.,..-.......-.;-,. 95 94 taining' the accelerators intensified the bleaching action liter was prepared:

i r Active oxygen content of I i ath after- Bath I 30min. 60min. 120mm.

' Percent Percent Percent (a) without accelerator V 99' (b) with accelerator 75 As can be seen from such table, the bath containing the nitrile liberated oxygen much more rapidly than the bath omitting such accelerator. The pH of the wash baths was 9.5.

'- Example 7 An aqueous wash bath of the following composition 7 per liter was prepared:

5.70 g. Marseilles soap 1.50 g. calcined soda 0.75 g. sodium pyrophosphate 0.75 g. sodium tripolyphosphate 0.70 g. dry waterglass 0.60 g. sodium perborate 0.30 g. terephthalic acid dinitrile This bath was used to wash a regenerated cellulose staple fiber textile fabric which had been soiled with blueberries at a fabric to bath ratio of 1:50 for 45 minutes at 60 C. In view of the accelerated oxygen liberation caused by the presence of the nitrile the same whitening effect was obtained as when the same textile fabric soiled with blueberries was washed for 45 minutes at 90 C. in a bath of the same composition but omitting the terephthalic acid dinitrile.

Example 8 A cotton fabric soiled with fruit juice was washed at 60 C. at a fabric-bath ratio of 1:20 for 2 hours in a bath which contained 10 g. Marseilles soap 2 g. sodium pyrophosphate 0.5 gsodium perborate 0.3 g. phthalonitrile per liter.

The whitening effect obtained was the same as with an analogously conducted boil wash in a bath omitting the nitrileactivator. Example 9 Work pieces of Bemberg silk (cuprammonium rayon) which had been soiled with tea were washedfor 2 hours at 60 C.'at a fabric to bath ratio of 1:25 in a bath containing 10 g. Marseilles soap 2 g. sodium pyrophosphate 0.5 g. sodium perborate 0.3 g. tetramethylene dinitrile perliter.

. it, 7 The washing elfect corresponded about to'that obtained with a boil wash analogously conducted with a bath of the same condition but omitting the nitrile activator.

Example 10 A wash bath containing 10 g. Marseilles soap 2 g. sodium pyrophosphate 0.5 g. sodium perborate 0.2 g. methylene-bis-iminoacetonitrile per liter was prepared and rayon staple fiber fabric soiled with red wine placed therein and treated therein for 45 minutes at 65 C. ata fabric to bath ratio of 1:50. The cleaning effect obtained was satisfactory, 56% of the active xygen content of the bath was consumed during the treatment. 0n the other hand, in a bath of the same composition but omitting the methylenebis-iminoacetonitrile only 6% of the active oxygen was consumed.

Example 11 Cotton nettle cloth which had been lightly soiled with chocolate milk was treated for 2 hours at 60 C; in an aqueous bath containing 5.70 g. Marseilles soap 1.50 g. calc. soda 0.75 g. sodium pyrophosphate 0.75 g. sodium tripolyphosphate 0.70 g. dry waterglass 0.60 g. sodium perborate 0.30 g. dimethyl-diamino-succinic acid dinitrile per liter. 1

As a comparison, a portion of such soiled cloth was treated under the same conditions in a bath of the same composition but omitting the nitrile activator. The ratio of cloth to bath in both instances was 1:50.

The soil was removed to a much greater extent in the activated bath than in the unactivated bath.

Example 12 Swatches of fabric which were soiled with a copying pencil were treated at 60 C. with occasional movement in a washing and bleaching bath containing 10 g. Marseilles soap 7 2 g. sodium pyrophosphate 2 g. hydrogen peroxide (30%) 0.3 g. nitrilotriacetic acid nitrile per liter. The ratio of fabric to bath was 1:50. A comparative test was carried out with the same bath but omitting the nitrilotriacetic acid nitrile under boil wash conditions. The degree of lightening of the fabric was the same in the bath containing the nitrilotriacetic acid nitrile at 60 C. as was obtained in the boil wash in the absenceof such activator.

The active oxygen content of both baths was about the same, as can be seen from the following table:

Active oxygen content of bath af ter- Bath 30 min. 60 min. min.

- Percent Percent Percent activated wash at 60 C 68 48 39 unactlvated boil wash 66 51 36 Example 13 Poplin which had been dyed with Sirius light blue GL, a dye which is sensitive to oxygen bleaching agents, was treated for 1% hours at 60 C. with a washing bath at a fabric to bath ratio of 1:50. The bath used contain d V p v a 7.0 g. soap shavings 2.0 g. sodium 'p'yrophospliate' 1.0 g. sodium perborate 0.2 g. nitrilotriacetic acid nitrile per liter.

It was found that the thus treated fabric lightened up as much as a fabric treated in the same bath but with the omission of the nitrilotriacetic acid nitrile under slow heating to the boiling point.

We claim:

l.' In a process for the treatment of organic fibrous materials with an aqueous bath containing an inorganic peroxidic bleaching compound, the step which comprises carrying out such treatment in the presence of an organic 'nitrile compound possessing at least limited solubility in said bath.

2. The process of claim 1 in which the proportion of nitrile compound present is sufficient to provide about one nitrile group per mol of peroxidic oxygen.

3. The process of claim 1 in which said treatment is carried out at a temperature between 50 and 80 C.

4 The process of claim 1 in which said bath also contains a detergent.

5. The process of claim l'in which said bath also contains a stabilizer for said peroiiidic compound. 6. The process of claim 1 in which said bath also contains a protective agent for the fibrous material treated; 7. A bleaching composition comprisingan inorganic peroxidic bleaching compound and an organic nitrile compound possessing at least limited solubility in water.

References Cited in the file of this patent UNITED STATES PATENTS 2,152,520 Lind as. Mar. 28, 1939 2,205,995 Ulrich et a1 June 25, 1940 2,730,428 Lindner Jan. 10, 1956 FOREIGN PATENTS 211,283 Switzerland Dec. 2, 1940

Claims (1)

1. IN A PROCESS FOR THE TREATMENT OF ORGANIC FIBROUS MATERIALS WITH AN AQUEOUS BATH CONTAINING AN INORGANIC PEROXIDIC BLEACHING COMPOUND, THE STEP WHICH COMPRISES CARRYING OUT SUCH TREATMENT IN THE PRESENCE OF AN ORGANIC NITRILE COMPOUND POSSESSING AT LEAST LIMITED SOLUBILITY IN SAID BATH.