US 2512195 A
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Patented June 20, 1950 METHOD OF WATERPROOFING GELLULOSE TEXTILES Christian Benet, Glmr, Switzerland- No Drawing. Application May '7, 1946, Serial No. 668,004. In Switzerland March 4, 1939 3 Claims.
1 This is a, continuation-in-part of applicant's application No. 332,041 filed March 2, 1940, and now abandoned.
It is a known fact, that textiles or fabrics from natural or transformed cellulose (regeneratedcellulose staple fibres, viscose or other rayons) can be rendered shrinkproof, waterproof and crease-proof by treating these textiles with aldehydes, carbamides or derivatives of carbamides, octadecyl-oxymethyl-pyridinium chloride (as known under the registered trade-mark Velan) or related product and a catalyser, i. e. a weak acid or other substance having an acid reaction. In order to simplify the terminology in the specification and claims only aldehyde, carbamide, Velan and catalysers are referred to but it is to be understood that these terms include the deriva-- tives of these compounds.
This prior suggested method could not be successfully introduced into practice for the reason that by its application the fibre is weakened in some unexplained manner which weakness is very likely due to a considerable reduction in the elasticity of elongation, with the result, that the fibre becomes brittle.
In the known methods for treating cellulose containing textiles, the ratio of aldehyde and carbamide was always so chosen, that the amount of the two constituents was stoichiometrically sufficient to allow the formation of the resin from the two components, those skilled in the art being formerly of the opinion that the desired properties are imparted to the textile by the formation of the resin in and on the fibre. Besides the Velan was intended partially to etherify the cellulose in the presence of the catalyst.
It has now been found as a very surprising fact that this reduction by quality can be avoided in treating the fibre with a great excess of aldehyde. The ratio of aldehyde tocarbamide according to the present invention is so chosen that the carbamide is only present in a fraction of the amount required stoichiometrically for the formation of water-proofness and crease-proofness areob-- tained. The excess of aldehyde avoids the formation of resin in thefibre in a quantity which would otherwise impart brittleness to the fibre which objectionable property was imparted by previous methods discussed above.
The presence of an excess of aldehyde also promotes the etheriflcation of the cellulose by the Velan. Therefore a much more valuable product is obtained than heretofore.
' For example the treatment of fabrics with a solution of the above mentioned type in which the proportion of weight between a 40% formaldehyde solution and dimethylol-urea was 250:30 i. e. 1:0.12 has been found to give very satisfying results. In other words, the ratio by weight between the formaldehyde and dimethylol urea is :30 or 1:03.
In proceeding according to the invention the manner in which the different agents are applied to the textile fibres is immaterial. It may be done either conjointly in a single solution or dispersion or in several component solutions or else by applying the dissolved or dispersed reagents in any desired succession. The work may be effected with or without intermediate drying and, if desired, a heat-aftertreatment may be provided. The latter is, however, required only in particularcases, namely, when certain aldehydes, or substances splitting oil aldehydes, are used, or certain catalysers. As a rule, ordinary drying, that is, hanging the material to dry, sumces for the reaction to be completed.
As substances for bringing about the chemical interaction of the aldehyde the following may serve:
Aldehydes of the aromatic or aliphatic series or derivatives thereof, monoor polyaldehydes, aldehydic acids or aldehyde alcoholates, or other derivatives or substitution products of aldehydes, nitrogen containing aldehyde compounds, aldehyde bisulphites, polymerised aldehyde compounds, as well as compounds capable of splitting oif aldehydes. Specifically the following substances may be mentioned: Formaldehyde,
acetic aldehyde, paraldehyde, trioxymethylena be used, particularly the latter substances, and more explicitly: organic or inorganic acids'or acid salts thereof capable of splitting off acids, acids of the aliphatic or aromatic series or salts thereof,
as well as mixtures of two or more salts, two or more acids, acids with salts or two or more acids. All kinds of mixed catalysers are also applicable without restriction.
As particularly effective catalysers the following may be mentioned: boric acid, lactic acid, succinic acid, acetic acid, chloracetic acid, formic acid, oxalic acid, sulphonic acids of the organic series, such as benzene sulphonic acid, sulphanilic acid, 2-amino-8-naphth0l-6-sulphonic acid, l-naphthol-5-sulphonic acid, -amino-B-naphthol-3.6-disulphonic acid and other naphtholoramino-naphthol-sulphonic acids and their salts, ammonium-sulphate, ammonium sulpho-cyanide, salts of phosphoric acids and persulphonic acids, persulphonic acids, salts of the acids derived from sulphur-0r chlorine, aluminium chloride, silicium tetrachloride, acetate of'alumina, anda number of salts of the heavy and light metals. These compounds are given by way of example only without limiting the present inven to be obtained to which end also the temperature -mus.t be taken into account dependent upon whether a heat-aftertreatment is to follow immediately or separately at a later time. It is advantageous if the fabric is preliminarily dried ata low temperature in order to prevent premature reaction, which, by way of example, is
- absolutely necessary if anintermediate shaption to these. catalysers, stress being laid uponthe'fact that the aforementioned products can be applied not only singly but also as mixed cat-w alysers in any desired combinationsandin any. desired number of varied mixing ratios without restriction to the number or percentage of the component parts of the mixed catalyser. In connectioniwith reactions of thealdehy'de: with the cellulose, it advantageous to use means of transmission or buffering agents in adchosen, themust-be carried outat terns,
ing treatment or any suitable mechanical finishing operation, for example, a non-shrink finishing treatment is to take place. .Dependent upon the substances particularly. the catalyser peratures ranging between 60'I5 C. Indrying non-shrink goods, the-measures ordered must be The'same holds'good if sheet-aftertreatment is provided for fixing the'goods'true -'to'the measures ordered. In the course of this dition to the catalysers. Substances ofithis kind are capable-.of-reacting with the aldehyde 'and of splittingit oii again, so. that, the. expression transmission means is warranted. i As: substances, foraserving this purpose the following. enter. into the question: Small amounts of urea, thio-urea,
methylene-urea, methylal, dimethyl-urea,- the procedure the dimensions of the goods, having been stretched outof-true'length' in the preare adjusted to thecorrect lengths advantageously by means of- .tentering frames, needle frames (with .or without-inherent lead). 4 felt calenders shrinkage, or machines now being built forthispurpose. If desired, this 'rectiflcation can be: effected byallowance for the ordinary shrinkage-in the wash and the goods accordingly dimensioned is then fixed by low water soluble condensation stages of 'urea,.
thio-urea-or mixtures thereof with aldehydes, especially formaldehyde, further, the lower condensation stages of the resins of a character similar to that of sulfines, compounds of aldehydes with polysulphides, yellow or colorless ammonium sulphide (NH4MS, also of salts of the rhodanic acid, etc. Concerning these substances it is emphasized that the same are not intended to form artificial resins in or on the fibre, but, in consideration of their presence in an entirely too small proportionate amount for producing an effect similar to that obtained by means of artificial resins, these substances act as mere transmission and reaction mediating means and as substances for-regulating the course of the reaction.
with the one or more impregnating liquors important additions may be incorporated, such as sizing materials, starch, gelatine, glucose, various sugars, soluble cellulose derivatives, such as methyl-cellulose, etc., further, emulsions of natural or synthetic rubber (latex), natural or synthetic rubber with or without vulcanising agents, colours, pigments, softening agents, fillers, wet ting agents or water repelling or refractory subtances, if desired.
The chemicals used for carrying the method into effect may be incorporated with the fabric singly or jointly in dissolved or dispersed state, either by impregnating the fabric throughout or by local application to the fabric in the form of a pattern by printing, spraying, reserve printing, or by partial immersion as well as by mechanical reserving (forming pockets in the fabric by knotting) i with this mode of procedure it is immaterial washingso asto be fast to dimensional change in subsequent washing.-
If it is required to give-to-the goods a lasting form, for example, a stamped form or otherrelief patterning, this must be effected on the preliminarily impregnated-ware in moist or dry state prior to the interaction of the aldehyde,
and under certain circumstances the plasticity may even be obtained by swelling the goods. This mechanical forming of a pattern may be combined with the application of colours, pigments or metal powder, if desired, incorporated with binders, so that the raised or the depressed portions become light reflecting.
In the afore-mentioned modes of procedure also the preliminary drying or the adjustment to the desired degree of humidity content must be effected under such conditions that no substantial reaction with the cellulose takes place. If it is required to improve the quality of the were in the course of the non-shrink treatment permanently in respect of lustre, feel and "substance," by ordinary calendaring, breaking, schreinering, ruilling. or chasing, this finishing measure must likewise be efiected by a heat treatment prior to the initiation of the interaction with the fibre.
The heat aftertreatment is dependent on all the factors hereinbefore mentioned and is carried out in accordance with the finishing effect required to be produced and in consideration of the agents used. Whereas the production of permanent stamping and molding eflects. as well as non shrink finishing brings with it the necessity for applying a separate heat treatment as a precautionary measure, which is also required in carrying out certain modes of the method for tween 140 to 150 C. Further, it is possible to carry out this treatment in autoclaves under pressure and/or under conditions of alternating superand sub-atmospheric pressures in presence or absence of the reaction solution. Moreover, the heating may take place in a gas atmos- CJI phere under pressure or without pressure in which I case the gas or steam'may constitute, substitute or amplify one of the reaction components, or the catalyser.
The method according to the invention makes also possible a further improvement of the process. In the known processes the effect imparted by the Velan was only regarded as a secondary effect to resin formation on the fibre.
amounts. In the present process however considerably better results and a total suppression of the weakening due to the reduction of the elasticity of elongation are obtained if such amounts of Velan are used which correspond to one part by weight of a 40% formaldehyde solution to 0.4-1 part by weight of a 10% Velan solution or 0.4 part by weight of formaldehyde to 0.04-0.1 part by weight of Velan. This increase of the concentration of Velan favours the reaction between Velan and aldehyde, which results in an enhanced etherification of the fibre.
For carrying out the method all textile materials made of natural or artificial cellulose as well as mixtures thereof in the form of flocks, yarns, mixed yarns, fabrics, mixed fabrics, hosiery, or matted goods are suitable. The textile material canbe treated according to the present method in any condition, such as crude, bleached condition or having been mercerized with acids or alkalies, parchmentized, dyed, printed, embroidered, etc. Also mixed yarns or mixed fabrics made of the afore-mentioned textiles and of animal fibres or artificial resin fibres or patented goods of all kinds are suitable for being subjected to this refining.
Example 1 A cotton fiock in bleached white condition or preliminarily dyed (particularly with genuine dyestuffs) is thoroughly soaked at 35 C. for a longer time with a solution containing 250 g. of 40% formaldehyde solution 100 g. of 10% Velan PF solution 30 g. of dimethylol urea 8 g. of ammonium sulphate 28 g. of sodium acetate diluted with water up to 1000 g.
and is then centrifuged, dried at 60 C., and subsequently heated to 150 C. for 10 min. This flock is used as a nap for spinning together with cotton, and the yarn or fabric made therefrom then receives 50 little color that a pronounced nap color effect is obtained.
Therefore this substance was only used in little' Example 2 A crepe-satin-fabric made of viscose is impregnated in a solution containing and is printed by adding a small amount of a thickener (gum, tragacanth, methyl cellulose), and is subsequently dried at low temperature. Thereupon the fabric, when provided with a required moisture content, inclusive of dry condition, is subjected to a mechanical shaping (stamping, calendering, shoving, etc), and is" then heated to 145 to 155 C. for 6 min. The fabric can then be washed, if desired, whereupon a permanent stamping effect is created. In applying the reaction mixture topically, washing out or slight steaming is required, so that the stamping effect is removed from the area not treated and is thus retained only on the patterned portions.
Alternatively, the processing may be such that the fabric after having been impregnated is printed with reserves of a kind preventing reaction with the fibre, whereupon the fabric is subjected either directly to a condensation treatment or prior to this to a. stamping treatment. In the former case the reserved portions are tinged darker shades during the subsequent dyeing, whereas in the latter case the reserved portions display no shaping or fashioning after the fabric has been washed out.- This modification can be varied by adding dyes or pigments toin the presence of a, catalyst dimethylol urea, an
aldehyde, and octadecyloxymethyl pyridinium chloride, respectively, in the approximate ratios by weight of 3:10-20:1-2 wherein the dimethylol urea is present in a quantity which if used alone would not form a crease-proofing resin coating,
and thereafter curing the treated textiles at a temperature which" causes a reaction with said textiles and imparts shrink-proof water-repellent and crease-proof properties thereto.
2. A method for treating cellulose textiles whereby they are rendered shrink-proof, waterrepellent, and crease-proof which comprises applying to said textiles in an aqueous medium and in the presence of an acidcatalyst dimethylol urea, formaldehyde, and octadecyloxymethyl pyridinium chloride, respectively, in the approximate ratios by weight of 3:10-20:1-2 wherein the dimethylol urea is present in a quantity which if used alone would not form a crease-proofing resin coating, and thereafter curing the treated textiles at a temperature which causes a reaction with said textiles and imparts shrink-proof, water-repellent, and crease-proof properties thereto.
3. A method for treating cellulose textiles whereby they are rendered shrink-proof, waterrepellent, and crease-proof which comprises applying to said textiles in an aqueous medium and in the presence of an acid catalyst dimethylol urea, formaldehyde, and octadecyloxymethyl 7 pyridinium chloride, respectively, in the approximate ratios by weight of 0.3:1:0.1 wherein the dlmethylol urea is present in a quantity which if used alone would not form a crease-proofing resin coating, and thereafter curing the treated textiles at a temperature which causes a reaction with said textiles and imparts shrink-proof, water-repellent, and crease-proof properties thereto.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 2,142,623 Whinfleld Jan. 3, 1939 2,238,839 Watkins Apr. 15, 1941 2,301,352 Wolf Nov. 10, 1942 FOREIGN PATENTS Country Date Great Britain July 10, 1930 Italy Aug. 19, 1936 Great Britain Feb. 15, 1938 Great Britain Nov. 14, 1938 Great Britain Nov. 18, 1938 Great Britain Feb. 1, 1939 Great Britain May 30, 1939 Great Britain June 27, 1939 OTHER. REFERENCES Hall: Article in Amer. Dyestufl Rep., June 19, 15 1933, pages 379-381, and 399-401.