US3508858A - Process and product for improving the textile characteristics of natural and synthetic fibers and fibers obtained thereby - Google Patents

Description

United States Patent 3,508,858 PROCESS AND PRODUCT FOR IMPROVING THE TEXTILE CHARACTERISTICS OF NATURAL AND SYNTHETIC FIBERS AND FIBERS OBTAINED THEREBY Vittorino Cadario and Davide Miglierina, Gozzano, Novara, Italy, assignors to Bemberg S.p.A., Gozzano, Novara, Italy, a company of Italy N0 Drawing. Filed Jan. 5, 1967, Ser. No. 607,384 Claims priority, applicatitg:S Italy, Jan. 11, 1966,

Int. Cl. D06m 13/34 US. Cl. 8115.5 15 Claims ABSTRACT OF THE DISCLOSURE A process for permanently imparting improved textile characteristics to natural and synthetic fibers having in their molecules free hydroxyl or amino groupings or mobile hydrogen atoms. The fiber is treated with an aqueous bath containing a compound having the general formula wherein R is an aliphatic radical formed by a chain of from 14 to 30 carbon atoms, X is a halogen atom, Ar is an aromatic radical selected from the group consisting of benzene, naphthalene, biphenyl, stilbene, and n is an integer comprised between 1 and 4.

This invention relates to a process and a product for permanently imparting improved textile characteristics to natural, and synthetic fibers having in their molecules free hydroxyl and aminic radicals or mobile hydrogen atoms, said groupings being capable of reacting with the halogen atoms of a compound which contains in its molecule at least a symmetrical triazine ring in which the halogen atoms are present as the side substituents so as to form a stable covalent bond between said fiber and said compound.

Processes of this kind are already known. More particularly, dyeing processes are known, of widespread use in the cellulosic fiber field, in which the compound which becomes bound to the fiber is a so-called reactive dye.

In the conventional dyeing processes, a chemical reaction is caused to occur between the free hydroxyl or aminic groupings or the mobile hydrogens of a natural, or synthetic fiber, and one or more halogen atoms which are present as the side substituents of a symmetrical triazine ring which is an integral part of the dyestutf molecule. By so doing, the dyestulf molecule is stably fixed to the fiber by a covalent bond.

The advantage of said dyeing processes with reactive dyes essentialy lies in the improved resistance the dye has to wet treatments, such as, for example, washing.

There have been disclosed, inter alia, reactive dyestuffs which contain, as an integral part of their molecule, at least a symmetrical triazine ring, carrying one or more chlorine atoms as side substituents: for example, a bichlorotriazine, or a monochlorotriazine ring.

Up to now, however, the considerable reactivity towards natural, and synthetic fibers, as exhibited by the compounds which contain in their molecules at least a symmetrical triazine ring with chlorine atoms as their side substituents, had been exploited nearly exclusively for introducing dyestuff molecules into the fiber.

It has now been found that it is possible to impart in a permanent way improved textile characteristics, apart from dyeing, to natural, and synthetic fibers by causing a compound, which contains in its molecule, in addition to the symmetrical triazine ring with halogen atoms as side substituent, also certain radicals, to be reacted with the hydroxyl or aminic groups or with the mobile hydrogen atoms of the fiber.

When processing natural, and synthetic fibers, irrespective of the fact that they are in the form of a thread, a staple, or a yarn, it is customary to revive the fiber with formulations of lubricants, such as mineral oils, synthetic Waxes and other like substances, to impart to the fiber a soft and handy touch and to facilitate the processing from the fiber to the end product.

The lubricant formulations are normally obtained by emulsifying them in water or another non-solvent for the fiber. However, the preparation could also be formed by a mere admixture of the lubricants or even, by a single lubricant.

A drawback which is common to all these preparations is that they can be very readily removed from the fiber by washing, so that the same fiber loses, partly or entirely, that soft and handy touch which had been imparted thereto.

When processing synthetic fibers, moreover, where rather drastic heat treatments are often resorted to in order that quite particular effects, such as bulk and resiliency, may be obtained, another shortcoming appears. As a matter of fact, any heat treatment is such as often to cause an evaporation of the most volatile components of the preparation and, at times, a yellow discoloration induced by the degradation of certain components which are temperature-sensitive. If so, in addition to a damage for the touch of the fiber, the latter losing its softness and slidability, there is a degradation also of the color of the fiber, which turns to be yellowish.

Furthermore, many natural, and synthetic fibers have not, as themselves, an adequate whiteness rating, which, conversely, is required for many uses. In order that said drawback might be done away with, resort has been had hitherto to the so-called optical bleaching agents, a numerous group of Which consists of stilbene derivatives. These optical bleaching agents actually impart a considerable whiteness to the fibers, but are nonetheless affected by the defect that they are not washing fast, especially whenever repeated washings are effected as is the case when washing finished textile products at home. Also the light-fastness is very limited.

All the shortcomings enumerated above, which are inherent in the conventionally used processes for imparting to natural, and synthetic fibers improved textile characteristics, can be virtually done away with by the process according to this invention. According to said process, improved textile characteristics are permanently imparted to natural, and synthetic fibers having in their molecules free hydroxyl or amino radicals or mobile hydrogen atoms, by a treatment in an aqueous bath of a compound having the general formula:

wherein R is a saturated or unsaturated aliphatic radical consisting of a chain of 14 to 30 carbon atoms, X is a halogen atom, AI is an aromatic radical selected from the group consisting of benzene, naphthalene, biphenyl, stilbene, and n is an integer comprised between 1 and 4.

The aliphatic radical being present in the above defined compound is responsible for the characteristics of soft hand and the slidability of the fiber as treated with said compound, said characteristics being conferred, according to the prior art, with the aid of lubricant formulations, which were poorly adherent to the fiber.

It has been found that the best results are achieved with an aliphatic radical having preferably from 16 to 22 carbon atoms, either a saturated or an unsaturated radical. Among the unsaturated radicals, those having a single double-bond in the carbon atoms chain are preferred.

Usually, the aliphatic radical will consist of a linear chain of carbon atoms. However, no departure from the scope of the invention is involved by introducing into the compound as defined above an aliphatic radical having a branched chain of carbon atoms or having side substituents, providing that the same effect of permanent lubrication is retained.

In the compound as defined above, Ar is an aromatic radical selected from the group consisting of benzene, naphthalene, stilbene, in which one or more sulphonic groups are present as side substituents. Said sulphonic groupings render the compound water-soluble, which is an advantage from a practical standpoint. Thus, the vital function of the aromatic radical in the reactive compound is to act as a carrier of solubilizing groups.

The water-solubility of the reactive compound is, in general, a function of the number of sulphonic groupings which are present as the side substituents. Satisfactory solubility values are obtained with two sulphonic groupings. However, when it is desired to dissolve the reactive compound into a nonaqueous solvent, then the presence of sulphonic groupings would be no longer necessary but, conversely, would be undesirable.

As side substituents of the aromatic radical, in lieu of the sulphonic groupings, also carboxyls could be introduced, or both sulphonic and carboxyl groupings could be present in the same aromatic radical. Also in such cases the effect of rendering the compound Water-soluble would be obtained.

If one desires to impart to the fiber, in addition to a soft and slidable band, also optical whiteness characteristics, then the radical Ar should be a stilbene radical. When Ar is a benzene, naphthalene, biphenyl radical, no optical whiteness characteristics are obtained: however, the reactive compound has an improved solubility over that obtained when Ar is a stilbene radical, this fact being susceptible of exploitation to obtain an improved softness of the fiber.

It is preferable, as a general rule, that the halogen atom which is present as the side substituent in the symmetrical triazine ring is a chlorine atom on account of its more intensive reactivity towards the free hydroxyl or amino radicals and the hydrogen mobile atoms of the fiber. However, also other halogen atoms, such as bromine, iodine, fiuorine, exhibit an adequate reactivity.

Fibers which contain free hydroxyl groupings are, in general, the cellulosic fibers, both natural and regenerated. Among the free-hydroxyl-containing synthetic fibers, there are the polyesters. Natural fibers, such as wool and silk, and synthetic fibers, such as the polyarnides, contain free amino groups. Polyamides also contain mobile hydrogen atoms, on account of the repetitive presence of the CONH-- grouping in their molecules. In said grouping, the hydrogen atoms is mobile, that is highly reactive. Also the polyurethane fibers contain the grouping CONH-- so that they are enabled to react with the reactive compound as defined above.

To the end of the treatment of the fiber with the reactive compound as defined above, a practice which has proven advantageous was to dissolve the compound into an aqueous bath, having a concentration of from 0.1

t'il

gm. to 3 gms. per liter, 1 gm. per liter being preferred.

The fibers, in the form of bundles, cheeses or staples, are soaked in said bath, the latter being circulated by a pump. Any conventional implementation as used for dyeing fibers or for impregnating them with the already enumerated lubricants could be adopted for carrying out the treatment, provided it is suitable for the particular form of the fiber.

The bath ratio is maintained between 1:10 and 1:30, but is preferably adjusted between 1:20 and 1:30.

The temperature of the bath can be comprised between 40 C. and C., according to the fiber undergoing treatment.

The duration of the treatment varies from 1 to 3 hours, according to the fiber.

In order to encourage the exhaustion of the reactive compound dissolved in the treatment bath, an addition to the bath of alkaline or acidic electrolytes has proven to be advantageous. In the case of cellulosic fibers, both natural and regenerated, the added electrolytes should be alkaline such as sodium sulphate, sodium bicarbonate, sodium triphosphate. Slightly alkaline environments are also suitable for silk. In the case of natural fibers such as wool and of synthetic fibers such as polyamides, polyesters, polyurethanes, the electrolyte should be an acid, both organic and inorganic. In general, however, it is wiser not to work at pH values under 1 so as to prevent any degradation of the fiber.

In order that the invention may be more clearly understood, the following examples are reported, which, however, should not be construed as limitations of the invention.

EXAMPLE 1 The synthesis of one of the reactive compounds whose eloss has been defined by the general formula reported in the foregoing, can be carried out as follows:

A solution of 18.4 gms. (0.1 mole) of cyanuryl chloride (trichlorotriazine) in mls. acetone is poured, with stirring, in 500 mls. distilled water, containing 500 gms. of ice lumps.

To the suspension which has thus been formed, a neutral aqueous solution of 25.3 gms. (0.1 mole) of 2:5- anilinedisulphonic acid in 200 mls. water is added dropwise during a time of about 30 mins. Upon completion of said addition, the pH of the reaction mass is adjusted with aqueous sodium carbonate until attaining a pH of 6.006.5.

The following reaction has thus taken place:

I so rr I HzN 01 C1 N $0311 I f aH 1101 01 -Q l scan The reaction mass is stirred again for 30 mins., whereafter a solution of 26.8 gms. (0.1 mole) of 9-octadeceneamine (commercially known also as oleylamine) in 100 mls. acetone, and a solution of 8.4 gms. (0.1 mole) of sodium bicarbonate in 200 mls. water, are added thereto.

The reaction mass is stirred for about 3 hours at a temperature of 35 C., until completing the reaction.

During this second step of the synthesis, the following reaction takes place:

I HCl Another example of synthesis of one of the reactive compounds whose general formula has been given above, can be effected as follows.

A solution of 9.2 gms. (0.05 mole) of cyanuryl chloride (trichlorotriazine) in 65 mls. acetone is poured with stirring into 250 mls. distilled water containing 250 gms. ice. To the suspension thus formed, a neutral aqueous solution of 14.3 gms. (0.05 mole) of the sodium salt of the p-amino-stilbene-Z:2'-disulphonic acid in 500 mls. distilled water, is added dropwise during a period of time of 30 mins.

Upon completion of said addition, the pH of the reaction mass is adjusted with aqueous sodium carbonate until reaching a pH value of 600-65. The mass is stirred for 30 additional minutes and is diluted with water to make up 2 liters.

To the solution thus obtained there are added a solution of 13.4 gms. (0.05 mole) of hexadecylamine (also known as cetylamine) in 50 mls. acetone and a solu tion of 4.2 gms. of sodium bicarbonate in 100 mls. water. The resultant solution is stirred for three hours at a temperature of about 35 C.

After said time the reaction is completed and the aqueous solution, which contains dissolved the synthesized compound corresponding to a general formula of the type defined above, can be directly used after having been diluted to the concentration requested for the bath, for the treatment of the fiber one desires to subject to the action of said compound.

The synthesized compound of this example has the following formula:

N CI LNH CHZCH placed in a device for dyeing hanks, consisting of an arm, to which the hanks are hung and through which a numher of small holes are formed, from said holes the treatment bath pours, thus impinging onto the hanks. The liquid which drops from the hanks is drawn "by a pump and recirculated.

The concentration of reactive product in the bath, whose synthesis has been described in Example 2, is of one gram per liter, the bath ratio being 1:25.

The bath is heated to C., whereafter the hank treatment is started. During 40 minutes, four increments of sodium sulphate are added, until totalling 50 gms. of sodium sulphate per liter of bath.

After this time and still maintaining the temperature of the bath at 80 C., the pH of the bath is adjusted with an addition of sodium bicarbonate (1 gm. per liter) so that the bath has eventually a pH of 8.1-8.3.

About 10 mins. after this addition, sodium triphos phate is added (6 gms. per liter) during 30 mins., and the bath is eventually kept at 80 C. for 60 additional minutes.

The bath is dumped, a washing for 5 mins. is carried out, with soapy water and then a few washings with pure water are effected.

Upon drying in hot air and reconditioning at room temperature, the hanks had a soft and slidable hand and a whiteness rating much higher than that of the usual hanks.

Even after repeated washings with capillary-active agents, the hanks did not show any decrease in softness and slidability and their whiteness was unaltered.

The same treatment made with sodium carbonate in lieu of sodium triphosphate, gave very much the same results.

EXAMPLE 4 Five hanks of raw wool were placed in the dyeing device described in the Example 3. A bath, containing 11.5% of formic acid and which was heated to 50 C., was then circulated for 10 mins. The bath ratio was 1:30.

After 10 minutes, the solution of the compound prepared according to the Example 1 was added to the bath so as to bring the concentration of said compound in the bath to 1%. On completion of the addition, the bath was kept under circulation for 25 mins., still at 50 C. Then the temperature was raised to C. and so was it maintained for 25 additional minutes. After that time, the bath was dumped and 3 fresh water washings were carried out.

Upon drying, the wool hanks exhibited a very soft hand which had a good resistance to wet treatments.

EXAMPLE 5 Seven hanks of natural silk were placed in the dyeing device described in Example 3. The treatment bath contained 1.5% of a compound, whose synthesis has been described in Example 1.

In the bath were dissolved also 20 gms. per liter of sodium sulphate and the temperature was adjusted at 80 C. The bath ratio Was 1:25.

The treatment of the hanks was started and continued for 15 minutes. After that time, 2 gms. per liter of sodium carbonate were added and the bath was circulated for 50 additional minutes, still at 80 C.

Eventually, the bath was dumped and four pure water washings were carried out, each with an intermediate soapy water washing.

The silk hanks, upon drying, had a softness which was much higher than that of the conventional hanks revived with a preparation formed by an aqueous emulsion of several higher fatty acid glycerides, and has an exceptional resistance to washing.

EXAMPLE 6 Ten cheeses of polyamide 6 yarn, matted with 0.5% of titanium dioxide, were placed in a dyeing device formed by a vertical foraminous stalk, into which the cheeses were slipped and from whose perforations the bath was caused to seep, said bath being then recirculated by a pump.

Prior to the treatment with the bath of reactive compound, synthesized according to the procedure of Example 2, a washing was carried out with a solution of a nonionic capillary-active agent, so as to remove from the yarn the lubricant oil formulation applied during spinning of said yarn.

The treatment bath contained 0.8% of the reactive compound and 3.5% of formic acid. The bath ratio was 1:25.

The bath, heated to 50 C., was circulated while simultaneously raising the temperature to 95 C. during 90 rnins. The temperature of 95 C. was maintained for 40 additional minutes.

After that time, the bath was dumped and there were carried out two washings with fresh water, one Washing with soapy water and a further fresh water washing. The yarn of the cheeses was then subjected to a. false twist treatment which involves, as is known, a rather drastic heat treatment. In spite of this, however, the yarn did not lose in any way its softness, nor its warm feel and was snow-white: no treatment-induced change was detected.

A polyamide-G yarn, which, contrarywise, had the conventional spinning preparation only, when subjected to the false twist treatment, lost by evaporation a part of the components of the formulation, this fact being clearly evidenced by the fumes evolved in the heat treatment area, and its color took a slightly more yellowish hue as compared with the untreated yarn.

What is claimed is:

1. A process for permanently imparting improtved textile characteristics to natural and synthetic fibers having in their molecule free hydroxyl or amino groupings or mobile hydrogen atoms, said groupings or atoms being capable of reacting with the halogen atoms of a compound containing in its molecule at least a symmetrical triazine ring, in which the halogen atoms are present as side substituents so as to form a stable covalent bond between said fiber and said compound, characterized in that the fiber is treated for a time variable from one to three hours, at a temperature of from 40 C. to 100 C., with an aqueous bath containing from 0.1 to 3.0 gms. per liter of a compound having the general formula wherein R is a saturated or unsaturated aliphatic hydrocarbon radical having a chain of from 14 to 30 carbon atoms, X is selected from the group consisting of chlorine, bromine, fluorine, and iodine, Ar is an aromatic radical selected from the group consisting of benzene, napththalene, biphenyl, and stilbene, and n is an integer of from 1 to 4.

2. A process according to claim 1, characterized in that the natural, or synthetic fiber is subjected to the treatment in the form of hanks or yarn cheeses.

3. A process according to claim 1, characterized in that the natural, or synthetic fiber is subjected to the treatment in staple form.

4. A process according to claim 1, characterized in that the fiber undergoing treatment 'is a natural fiber.

5. A process according to claim 1, characterized in that the fiber undergoing treatment is regenerated cellulose.

6. A process according to claim 1, characterized in that the fiber undergoing treatment is wool.

7. A process according to claim 1, characterized in that the fiber undergoing treatment is natural silk.

8. A process according to claim 1, characterized in that the fiber undergoing treatment is a polyamide.

9. A process according to claim 1, characterized in that the fiber undergoing treatment is a polyester having mobile hydrogen atoms.

10. A process according to claim 1, characterized in that the fiber undergoing treatment is polyurethane.

11. A natural or synthetic fiber treated according to the process as claimed in claim 1.

12. A process according to claim 1 characterized in that the fiber being treated is a cellulosic fiber and an alkaline electrolyte selected from the group consisting of sodium sulphate, sodium bicarbonate and sodium triphosphate in an amount capable of encouraging the exhaustion of the bath is added to the aqueous bath containing the compound which is reactive towards the fiber.

13. A process according to claim 1 characterized in that the fiber being treated is a synthetic fiber and formic acid in an amount capable of encouraging the eX haustion of the bath is added to the aqueous bath con taining the compound which is reactive towards the fiber.

14. A process according to claim 1 wherein Ar is stilbene.

15. A process according to claim 14 wherein X is chlorine.

References Cited UNITED STATES PATENTS OTHER REFERENCES Advances in Textile Processing, vol. 1, 1961, Textile Book Publishers, 'Inc., pp. 65-66.

Marsh, Crease Resisting Fabrics, Publishing Corp., p. 134.

H. Zollinger, Dyeing Mechanisms and Molecular Shape, American Dyestuft Reporter, March 1960, pp. 142-149.

196 2, Reinhold HERBERT B. GUYNN, Primary Examiner M. L. HALPERN, Assistant Examiner US. Cl. X.R.