US3206273A

US3206273A - Cellulosic textile finishing

Info

Publication number: US3206273A
Authority: US
Inventors: Munzel Fritz
Original assignee: Heberlein and Co AG
Current assignee: Heberlein and Co AG
Priority date: 1959-04-01
Filing date: 1961-07-19
Publication date: 1965-09-14
Anticipated expiration: 1982-09-14
Also published as: BE587866A; DE1174740B; CH386384A; US3140197A; GB906324A; NL244572A; CH383326A; BE606332A; GB917151A; NL266456A; CH7815959A4; DE1113677B

Description

United States Patent 3,206,273 CELLULOSIC TEXTILE FINISHING Fritz Munzel, Wattwil, Sanirt Gallen, Switzerland, as-

signor, by mesne assignments, to Heberlein & (10., A.G., Wattwil, Switzerland, a corporation of Switzerland No Drawing. Filed .luiy 19, 1961, Ser. No. 125,689 Claims priority, application Switzerland, July 22, 1960, 8,398/60 8 Claims. (Cl. 8116) This invention relates to an improved method of finishing cellulosic textile materials to improve certain physical properties thereof, particularly the crease resistance, ten

textile, and to the novel product thereby produced.

- not required.

sile or tearing strength, and the abrasive strength of the It is related to Heberlein et al. US. application No. 62,068, filed March 31, 1960, and constitutes an improvement over the method therein described.

The term cellulosic textile material as employed herein is intended to include films, yarns, fibers, filaments or threads as such or in the form of cast sheets, woven, knit, felted or non-woven fabrics, consisting of natural or re generated cellulose, as well as such fibers, fabrics, etc, which are made up of a major portion of cellulose or regenerated cellulose, but which also contain in addition a small quantity of non-cellulosic material.

It is Well known that in order to improve the crease resistance of natural or regenerated cellulose yarns or fabrics, for example, cotton, rayon, or mixed cotton and rayon goods, the yarn or fabric is impregnated with one or more well-known condensable resin-forming substances, for example a synthetic resin precondensate dispersed or dissolved in a fluid carrier containing a condensation catalyst which is usually acidic. Following impregnation the excess resin precondensate is squeezed out and the impregnataed fabric is then subjected to temperatures well above 100 C. for a time snificient to cure the resin. Textiles finished in this conventional manner at elevated temperature are substantially less durable than the unfinished or starting material. While conventional finishing imparts improvedcrease' resistance, this is accomplished at the expense of a marked reduction in fiber strength of the textile product, as evidenced either by appreciably reduced tensile or tearing strength or resistance to abrasion or both.

According to related Heberlein et a1. U.S. application Serial No. 62,068, a method is suggested whereby the cellulosic textile to be finished is first treated .with a condensable or resin-forming substance and subsequently subjected to ionizing radiation, more particularly to electromagnetic ionizing radiation, which facilitates condensation and curing of the resin-forming substance on the textile. The method thereof may be carried out with or without the usual condensation catalyst, but heat is The product produced by the related method exhibits'substantially improved crease resistance as compared with this property of the same conventionally finished textile. Tearing strength of the textile finished in accordance with the related application is in some instances, although not always, improved. Occasionally tearing strength is slightly reduced.

While it is generally agreed that a finish superior to that of the conventional method can be imparted to the textile by the method of the earlier related application, there is still a need for a method which will assure superior crease resistance results accompanied by improved tearing and abrasive strength, without degradation of the cellulose.

I have found that these results can be obtained by following the general procedures outlined in the related application as respects application of the condensable or resin-forming substance, but instead of subjecting the thus treated textile to electromagnetic ionizing radiation,

3,Z5,Z73 Patented Sept. 14, 1965 the impregnated material is irradiated with accelerated electrons of a critical low particle energy to a critical total dose.

It has already been proposed to employ accelerated electrons (beta radiation) to effect condensation of synthetic resins on cellulosic textiles, but the methods previously described have always employed very high energy beta particles. More particularly, the prior art techniques employ beta radiation of a particle energy of 2 mev. and higher, with the total doses irradiated being between about 5X10 and 7x10 rad. These prior art techniques have been acknowledge to be'insufiicient for the proper finishing of cellulosic textile materials in that they cause very extensive degradation of the cellulosic substrate thus rendering its further use as a fabric impossible. Furthermore, at these high energy levels satisfactory resin condensation is not achieved and an acceptable finish is thus not imparted to the fabric.

It has been established that extensive decomposition of cellulose and regenerated cellulose occurs when it is subjected to total doses of ionizing radiation above 25x10 rad. For example, at total doses of 5 l0 rad at least 10% of the cellulose is converted to sugars. Furthermore, many of the resin precondensates usually employed for the finishing of cellulosic textiles such as urea, melamine and ethyleneurea, are also sensitive to radiation and are extensively decomposed at total doses of more than 2.5 X 10 rad. Accordingly, the unsatisfactory results attending the aforementioned prior art attempts at finishing with the use of high energy beta particles is not surprising.

in accordance wtih the method of the present invention excellent resin condensation on the cellulosic material can be achieved without any significant degradation of the cellulose or the resin precondensate if the textile materials are subjected to the action of accelerated electrons of a critical particle energy of less than 1 mev., and if a total dose imparted is less than 2x10 rad. The present process contemplates the use of accelerated electrons of a particle energy between about 0.05 and 1 mev., and preferably between 0.05 and 0.6 mev., with irradiation being to a total dose above 10 but below 2x10 rad, preferably between 10 and 10 rad.

The excellent results obtained by the method of the present invention mentioned above and set forth in detail hereinafter are indeed surprising, since one skilled in the art would not expect that the irradiation of resin precondensate impregnated cellulosic textiles with accelerated electrons of such a low particle energy and at a comparatively low total dose would produce sufiicient resin condensation to effect the desired crease resistance and dimensional stability improvement. From the teachings of the prior art, one would assume that sufficient resin condensation or linking of the resin to the cellulosic molecule could not be achieved with accelerated electrons since at much higher doses and particle energies poor condensation is achieved and degradation of the cellulosic substrate is appreciable.

It is believed that the success of the method of the present invention is due to the fact that electromagnetic ionizing radiation (gamma rays) pass through the irradiated material on the shortest possible path, with at most only about 1% of their energy being absorbed by the cellulosic textile. On the other hand, accelerated electrons, which possess mass, are slowed down as a result of multiple collisions with the atoms of the cellulosic material or with atoms of the resin precondensate thus forming secondary electrons which-themselves collide with other atoms. At each collision of electrons energy is transferred and a relatively great part of the energy of the accelerated electrons is absorbed by the cellulosic textile and the condensable or resin-forming substance thereon. It has now been found that accelerated electrons of a very high particle energy, that is above about 1 mev., transfer so much energy during their passage through the cellulosic material that numerous scissions of the chain of the cellulosic molecule occur with resulting decomposition and destruction of the textile. If, in accordance with the present invention, accelerated electrons of low particle energy are irradiated into the cellulosic material there is a much smaller transfer of energy so that cellulose chain scission is very greatly reduced or eliminated, but the transferred energy is sufficient, perhaps being different in kind, to provide activation energy for the cellulose or resin precondensate to effect ionization and condensation.

Furthermore, in accordance with the present invention it has been established that decomposition of the cellulose at a certain irradiated total dose, e.g., l0 rad, is very substantially lower where accelerated electrons having a low particle energy, i.e., below 1 mev., are used as compared with electrons of a particle energy above 1 mev. Where, in accordance with the present invention, accelerated electrons of a particle energy of between about 0.05 and 0.6 mev. are employed, the total dose to which the cellulosic textile is exposed can be maintained at a sufficiently low value so that no decomposition of the cellulose worth mentioning takes place.

Accelerated electrons employed in accordance with the preesnt process may be produced by the conventional electron accelerators, such as the cascade, Van de Graaf or linear types. Radioactive substances such as Sr emitting beta radiation of a particle energy of 0.6 mev.,

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finishing of textiles of all kinds, as noted earlier, but is particularly useful in the treatment of sheet materials or fabrics. It is intended primarily for the crease-proof finishing and the imparting of dimensional stability to woven or knit cotton or rayon, or mixed cotton and rayon fabrics, and offers the further very significant advantage in that the tearing and abrasive strength of the starting or unfinished fabric is very substantially increased. The finished fabrics exhibit a pleasant soft hand.

In accordance with the present method it is also possible to impart to a fabric permanent embossing effects, such as gotfering, ribbing, schreinering, or moire effects, as well as calendaring effects with or Without friction. The method is also effective in the treatment of cellulosic textile yarns, filaments or threads. Excellent results are achieved in fabrics such as voiles and marquisettes fashioned of highly twisted yarns, which fabrics normally exhibit a strong tendency to shrink.

Moreover, fine fabrics of cotton or regenerated cellulose which have been stiffened or transparentized by treatment with concentrated sulfuric acid, cuprammonium solution or sodium zincate cellulose solution are very significantly improved by the present process, Without any decrease in fiber strength.

The method of the present invention will be further apparent from the following typical examples, which illustrate practical applications of the method and describe certain characteristics of the novel finished textile products.

Example I A cotton imitation poplin was singed, desized and bleached and thereupon impregnated with a solution C011- W MIN/ 1 M 11492 My party an Ettlllllft I H l H ill/lit it t. I l" i i and abrasive strength for the starting unfinished cotton poplin fabric and for fabric Sections A, B and C.

- It will be noted that simply impregnating the fabric with dimethy-lolethyleneurea and drying at 60'70 C. appreciably increased the crease angle, but at the expense of lowered tearing and abrasive strengths. Irradiation with 2 mev. particles effected some improvement in the abrasive strength and also in the warp tearing strength, but appreciably reduced the warp crease angle. On the other hand, Section C which was irradiated in accord ance with the method of the present invention employing low energy beta particles exhibited outstandingly superior crease angle, tearing strength and abrasive strength, as well as an improved hand as compared with Section B.

Example III Crease angle Tearing strength Abrasive in degrees in g. strength in number of rotations Warp Fill Warp Fill Starting material 8 200 195 3. 220 Irradiated 100 110 750 740 6. 140

Example IV A spun rayon gabardine fabric, pretreated in the usual manner, was impregnated with a solution of dimethylolethyleneurea, as described in Example I, and dried at 60-70 C. Thereupon it was irradiated with accelerated electrons of a particle energy of 0.12 mev. to a total dose of 10 rad. The thus treated fabric exhibited excellent abrasive strength and crease resistance and unimpaired tearing strength.

Example V A cotton imitation poplin fabric was impregnated with an aqueous solution containing per liter 100 g. melamineformaldehyde precondensate and 15 g. triethanolamine glycolate catalyst, squeezed out and dried at 60 C. Thereupon the fabric was irradiated with accelerated electrons of a particle energy of 0.1 mev. to a total dose of rad. After irradiation the fabric was washed with a soap soda solution at about 60 C., dried and rinsed with cold water. The thus treated fabric had the following properties:

Crease angle Tearing strength Abrasive in degrees in g. strength in number of rotations Warp Fill Warp Fill Starting material 47 59 880 880 15. 400 Irradiated 110 105 1, 030 1, 030 20. 810

6 Example VI The cotton imitation poplin fabric of Example V was impregnated with an aqueous solution containing per liter 102 g. of a diepoxide resin of the formula:

R=1 to 5 CH -groups and 6 g. zinc fluoroborate catalyst. It was then squeezed out and dried at 60 C., washed, dried and rinsed as descrebed in Example V. Thereupon it was irradiated with accelerated electrons of a particle energy of about 0.1 mev. to a total dose of 2 10 rad. The thus treated fabric exhibited the following properties:

The cotton imitation poplin fabric of Example V was impregnated with an aqueous solution containing per liter g. of a glycol polyacetal, the polymeric condensation product of diethyleneglycol and formaldehyde of the following general formula:

where X and Y are either H or CH OH, as described in US. Patent No. 2,786,081, and 40 g. MgCl .6H O as catalyst. The fabric was then squeezed out, dried at 60 C. and washed, dried and rinsed as described in Example V. It was thereupon irradiated with accelerated electrons of a particle energy of about 0.1 mev. to a total dose of 5 x 10 rad. The thus treated fabric exhibited the following properties:

Crease angle Tearing strength Abrasive in degrees in g. strength in number of rotations Warp Fill Warp Fill Starting Material 47 59 880 880 15.400 Irradiated 110 105 1, 890 1, 690 26. 930

I claim:

1. A method of finishing a cellulosic textile of the group consisting of cotton, rayon and mixtures thereof, which comprises impregnating the textile with a crease-resistance imparting condensable resin-forming substance disposed in a fluid carrier, and subsequently subjecting the impregnated textile to beta radiation of a particle energy between about 0.05 and 1 mev. to a total radiation dose between about 10 and 2 10 rad to condense the condensable substance on the textile and substantially improve the abrasion and tensile strengths of the starting textile.

2. A crease resistant cellulosic textile finished by the process of claim 1.

3. A method as set forth in claim 1 wherein the beta radiation is of a particle energy between about 0.05 and 0.6 mev.

4. A method as set forth in claim 1 wherein the fluid carrier is water.

5. A method as set forth in claim 1 wherein the impregnated textile is irradiated in wet condition.

6. A method as set forth in claim 1 wherein the impregnated textile is dried below about 100 C. before it is irradiated.

7. A method of finishing a fine cellulosic textile fabric of the group consisting of cotton, rayon and mixtures thereof, which comprises impregnating the textile with a crease-resistance imparting condensable resin-forming substance dispersed in a fluid carrier, and subsequently subjecting the impregnated textile to beta radiation of a particle energy between about 0.05 and 0.6 rnev. to a total radiation dose between about 10 and 10 rads to condense the coudensable substance on the textile and substantially improve the abrasion and tensile strengths of the starting textile.

8. A fine cellulosic textile fabric finished by the process of claim 7.

References Cited by the Examiner UNITED STATES PATENTS 2,940,869 6/60 Graham.

8 2,998,329 8/61 Sovish et al. 3,101,276 8/63 Hendricks 2.. 117-56 FOREIGN PATENTS 758,735 10/56 Great Britain. 845,690 8/60 Great Britain.

OTHER REFERENCES Blouin: Textile Research Journal, vol. 28, 198204 (1958).

Gilfillan: Textile Research Journal, vol. 25, 773-777 (1955).

Pan: Textile Research Journal, vol. 29, 415-421 (1959).

NORMAN G. TORCHIN, Primary Examiner.

MORRIS O. WOLK, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,206,273 September l4, 1965 Fritz Munzel hat error appears in the above numbered pat- It is hereby certified t etters Patent should read as ent requiring correction and that the said L corrected below.

lines 11 and 12, for "descrebed" read Column 6,

lines 32 to 35, the formula should appear as described shown below instead of as in the patent:

Signed and sealed this 3rd day of May 1966.

(SEAL) Attest:

EDWARD J. BRENNER ERNEST w. SWIDER \ttesting Officer Commissioner of Patents

Claims

1. A METHOD OF FINISHING A CELLULOSIC TEXTILE OF THE GROUP CONSISTING OF COTTON, RAYON AND MIXTURES THEREOF, WHICH COMPRISES IMPREGNATING THE TEXTILE WITH A CREASE-RESISTANCE IMPAIRING CONDENSABLE RESIN-FORMING SUBSTANCE DISPOSED IN A FLUID CARRIER, AND SUBSEQUENTLY SUBJECTING THE IMPREGNATED TEXTILE TO BETA RADIATION OF A PARTICLE ENERGY BETWEEN ABOUT 0.05 AND 1 MEV. TO A TOTAL RADIATION DOSE BETWEEN ABOUT 10**4 AND 2X10**6 RAD TO CONDENSE THE CONDENSABLE SUBSTANCE ON THE TEXTILE AND SUBSTANTIALLY IMPROVE THE ABRASION AND TENSILE STRENGTHS OF THE STARTING TEXTILE.