DE1248007B - Process for reducing the water absorbency and for making cellulose-containing textiles crease-resistant - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

D06m

German class: 8 k - 1/20

Number: 1 248 007

File number; C23447IVe / 8k

Filing date: February 20, 1961

Opened on: August 24, 1967

ben been, with the help of which it should be possible to cellulose and formaldehyde, optionally in the presence of metal salts. ode, oxidizing acids, a marriage ·: mix reaction accessible to maeJtien, For the difficulties that always arisen in practice, the term "tendering" has become common in the Anglo-Saxon literature. This is understood to mean a process in which a weakening of the cellulose fiber can be observed, ζ, Β, ίο because of the acidic conditions with which one has hitherto attempted to catalyze ^{the reaction of formaldehyde with the cellulose, albeit with some known ones} . Method occasionally somewhat ^ e friedigende results were obtained SQ it turned §ich over d (he time but imrner back out that with such a. Operation over extended product no uniform products are obtained tion periods of time headboard. Pie occasionally refereed favorable results are therefore not uniform ao reproducible, it is rather υ, να, random, results. in the experiments, DJE regenerated cellulosic fibers with aqueous Forrnaldeliyd and an acidic substance to impregnate the material is subsequently dried and heated. for example on Above IQO ⁰ C / During drying and heating, the reaction with the cellulose takes place. Obviously, some of the primarily sought-after results, e.g. a reduction in water absorbency and an increase in crease resistance and dimensional stability, can only be achieved at a relatively high temperature The reasons for the failure of the above The well-known procedures mentioned can be summarized as follows:

1. The tensile strength of the threads is often, Wahrs.ch.eirH borrowed as a result of the degrading action of the acidic catalyst on the fibers, strongly ver ^ diminishes,

2. The results are not consistent. The material can only be colored unevenly, and the water absorption of the treated fibers changes from load to load, although each is apparently treated in the same way.

3. The formaldehyde bath is being used incompletely. Only a small part can chemically react with the cellulose during the larger part is lost during drying and heating.

Attempts to make better use of the formaldehyde by increasing the proportion of acidic processes to reduce the amount of formaldehyde
Water absorbency and for
Anti-crease finishing of cellulose-containing
textiles

Addition to registration: - C 20423IY c / 8 Hr-Auslegeschrift 1237 527

Applicant:

LipacQ S, A "Basel (Switzerland)

Representative;

Dr, O. DUtmann, patent attorney,

Munich 90, Bereiteranger 15

Named as inventor:
George Cecil Daul,
Thomas Francis Drake,
Mobile, Ala. (V. St, A ₁ )

To achieve a catalyst, have an even stronger shown destructive effect on the fibers, dem-, opposite is an essential iyierkmal of the pin Invention is that, contrary to general practice, certain catalysts explained below in a practically neutral vein, even ba, sische ^ n Medium for the reaction of formaldehyde with Cellulose can be applied.

The patent application C20 423iyc / 8k (German Auslegeschrift 1 237 5.27) extends; to a method for reducing the Wassersa.ugfähigkeit, and crease-resistant finishing of cellulose-containing fabrics by reaction with an aqueous solution of a metal salt and formaldehyde or a aliphatic you or polyaldehyde or an aliphatic hydroxyaldehydes, which contains no more than carbon atoms; it is characte ?. rized that a magnesium halide is used as the metal salt and the textile material is impregnated with an 'aqueous solution of pH at least 5, the molar ratio of magnesium halide to aldehyde being at least 1:12, whereupon the textile material is dried and heated.

709 638/541

3 4

It has now been shown that it is desirable that the cellulose fibers after

Formation of this process as the metal salt zinc sulfate drying and heating 0.1 to 3% chemically

or a salt of a metal from group II of the periobond formaldehyde. This can be described as

dic system with a monobasic acid, which is converted into the amount of formaldehyde, which is

normal aqueous solution at 18 ⁰ C for at least 5 lysis with 12 η-sulfuric acid is set free,

50% is ionized, with the exception of a magnesium determine. The quantities just given are on

halide, in an amount of 0.003 gramol per air-dry weight of the original cellulose

100 g cellulose and a molar ratio based on metal. For cotton, the amount is

salt to formaldehyde of at least 1:17 chemically bound formaldehyde advantageously 0.1

can turn. ■ · i ₀ to 1.25%> while in the case of regenerated cellulose

When reacting with formaldehyde, the cellulose fibers can amount to 0.1 to 3%. If a tissue

loosely in fiber or other form. with higher crease resistance is required, more must

In the case of the salts of group II of the periodic formaldehyde are bound, as if only dimen system can be magnesium salts or earth stability is required. If z. B. an alkali salt (namely salts of calcium, barium and 15 textile fabric made of regenerated cellulose fibers a strontium) and cadmium or zinc salts with high crease resistance (at least 240 ° Monsanto) monobasic acids act. Magnesium salts and should be given in, then 0.8% bound form, a little less calcium salts are given before aldehyde (corresponding to a water absorbency of added. They are stable and effective in aqueous solutions about 40%), although already about 40% the formaldehyde at pH values above 6, e.g. B. 20 0.20% (corresponding to a water absorbency of pH values above 9, containing. About 48%) ^e i ^Qe g ^ute dimensional stability arise.

The monocarboxylic acid is preferably an inorganic For this purpose, the erfordernische on the cellulose acid, _z; Bi hydrogen chloride, hydrogen bromide, borrowed amounts of formaldehyde while drying, hydrogen iodide, nitric acid, perchloric acid or thi- somewhat larger. You can add 0.5 to 6 percent by weight of cyanoic acid. But it can also be 25 benzenesulfonic acid. Using textiles made from regenerated cellulose usually require 1 to 6%, while in the case of Baum examples for catalysts, which are necessary for the invented wool fabric, 0.5 to 4%. The processes according to the concession have proven successful are: Magne- tration of formaldehyde in aqueous solutions, the sium nitrate or perchlorate, calcium chloride, calcium bromide, to apply the formaldehyde to the cellulose iodide, nitrate or thiocyanate, strontium chloride, 30 fibers are used , are usually in the barium chloride, cadrnium chloride, zinc chloride or the same order of magnitude,
-nitrate, zinc sulfate and magnesium benzene sulfonate. As mentioned earlier, the amount of als

It is advantageous to use magnesium salts or an alkaline earth catalyst with a salt that acts as a salt of cellulose ^; the hydrates, when incorporated, form at least 0.003 gram mol per 100 grams of air heating _; at 90 ° C not all of their water 35 cellulose; it can lose between 0.0038 and 0.09 grammol. This is the case with magnesium perchlorate in particular 0.008 to 0.054 gram mol per 100 g and nitrate, calcium chloride, bromide, iodide and cellulose,
-nitrate, strontium chloride and barium chloride. In addition, the molar ratio of the salt to

According to the method according to the invention. formaldehyde at least 1:17, preferably min-

The cellulose used can also be in the form of paper, cardboard or at least 1:12; it can be as high as 1: 4 and

available as a film. However, it is especially valuable to be even 1: 1. This is especially true when

for textile fibers made of cellulose. Magnesium salt or an alkaline earth salt can be used for fibers.

natural fibers such as cotton, linen, in the case of zinc nitrate, the molar ratio of catalyst

Hemp, jute, ramie or sisal, or around regenerated sator to formaldehyde preferably no greater than

act artificial cellulose fibers, e.g. B. those that are 45 1:12.

with viscose, cuprammonium or the nitrate- The pH of the aqueous solution of molding processes produced or by saponifying fibers aldehyde, catalyst and water that of cellulose from cellulose esters, "e.g. cellulose acetate, obtained before drying and heating is incorporated have been. 'at least 5. If cotton is treated, is

The cellulose fibers can be in the same shape 50 the pH value preferably at least 6. If necessary, present, as in the description of the patent, the pH can be adjusted by adding sodium C 20 423 IV c / 8k (German Auslegeschrift carbonat, Bicarbonat oder Hydroxyd adjusted 1237 527) is given. Are particularly suitable. Commercially available formaldehyde can be used Textile fabric. ' aqueous formaldehyde with a concentration of

If desired, the cellulosic fibers can be used before about 40 percent by weight,

after impregnation. The drying of the impregnated cellulose can take place at

■■ The treatment of the cellulose fibers with mold 30 to 110 ⁰ C take place, preferably so that the

Aldehyde, metal salt and water can be made as the water content of the material to about 5%> loading

this in the description of the patent application is calculated on the weight of the completely dry

C20 423IVc / 8k (German Auslegeschrift 1237 527) 60 material, is reduced.

is specified. An aqueous solution is advantageous. The subsequent heating can be at 110 to 180.degree

of formaldehyde and metal salt on the fibers for a period of 30 minutes down to the bottom

brought. Then it is squeezed out and centrifuged for a few seconds. Using

until the fibers the desired amount of the solution of magnesium chloride as a catalyst becomes a

contain. The solution can also contain other solutions sufficient reaction of the formaldehyde with the

medium, such as methanol or ethanol, contain. You cellulose by heating to 160 ⁰ C for a period

but should reach at least 10 percent by weight of water in 1 to 8 minutes. In the case of some others

contain. Salts, e.g. in the case of barium chloride, require a longer

heating during or a treatment at elevated temperatures is desirable, e.g. B. 15 minutes or more, at 160 ° C. Strict heating conditions should be avoided if the pH is the Liquid in the material before drying is less than 6.

After the heat treatment, the cellulose-containing textiles can be washed with water, if desired with water that contains ammonia, urea or other substances that interact with formaldehyde react to remove the salt and any unbound formaldehyde.

In the following examples, the percentages are percentages by weight.

For example

Samples of viscose rayon staple fibers that have not yet dried at all, which are still in the gel state after spinning, are impregnated with aqueous solutions that contain 3 percent by weight HCHO, varying amounts of Mg (NO ₃ ) ₂ · 6H ₂ O and so much NaOH that the pH is 6.6. The samples are centrifuged until about 140% liquid, calculated on the dry weight of the fiber ίο containing at 8O ⁰ C heated 6 minutes and dried at 155 ⁰ C. They are then tested for water absorbency as well as for the strength and expansion of the individual fibers. The results are as follows :, .. '■ ... "', '.

Mg (NO ₃ ) _a . 6H ₂ O HCHO Molar ratio
Salt to HCHO Mole of salt water Trockeni _-:; Dry ° / o
in solution ° /.
in solution 1: 12.8 per 100 g
Cellulose absorbency
% strength
g / the ...,., strain
7o, 2.0 3 1: 8.5 0.0109 59 . 2.38 ■ · -. · 13.8 3.0 ■ 3. 1: 6.4 0.0163 53 2.16:. ·. 11.9 4.0 3 1: 5.1 0.0218 51 1.98 I: 10.4 5.0 3 1: 4.3 0.0272 50 1.94 10.3 6.0 3 0.0326 45 2.01 9.7

A control sample has a water absorbency (after drying) of 100%> a dry strength of 2.4 g / den and a dry elongation of 21%.

Example 2

The process according to Example 1 is _{repeated with Mg (C10 4} ) ₂ · 6H ₂ O as a catalyst. The pH of the solution is adjusted to 6.0. The results are as follows:

Mg (Cl ₄ )., · 6H ₂ O HCHO
⁰ U Mole
relationship
Salt too water
Suction
able to Dry
know-
consolidate Dry
know-
stretch 0 /
/ 0 in HCHO speed speed tion in solution solution 7o g / den 7o 2.4 3 1:13 44 2.24 10.3 3.0 3 1: 10.7 41 1.87 9.1 4.0 3 1: 8.1 40 1.82 8.1

Example 3

The procedure of Example 1 is _{repeated with ZnCl 2} as the catalyst at pH 5.4. The results are as follows:

ZnCl ₂ HCHO Molver water Dry Dry % % ratio suck firm deh in in Salt too capability speed tion solution solution HCHO % g / den % 0.9 3 1:15 56 2.04 13.0 1.8 3 1: 7.5 51 2.00 10.4 2.4 3 1: 5.7 43 1.98 19.2 3 3 1: 4.5 42 1.85 8.3

Example 4

The procedure of Example 1 is repeated with zinc sulfate as the catalyst. The pH of the solution is 5.5. The results are as follows:

ZnSO ₄ • 6H ₂ O HCHO Molver
holds nic water
Suction Dry
know- Dry
know- % ilclllIHo
O} | 1 ₇ 711 able to consolidate stretch % in HCHO speed speed tion in solution solution % g / den 7o ■ 1.8 3 1:16 58 1.99 12.7 2.4 3 1:12 55 1.90 12.3 3.0 3 1: 9.6 52 1.88 12.0 4.0 3 1: 7.2 48 1.89 8.8 5.0 3 1: 5.7 46 1.93 10.3 6.0 3 1: 4.8 45 2.16 12.5

Example 5

The following tissue is treated:

Warp and weft: yarns 3.25 cm cotton count, spun from 1.5 denier viscose rayon staple fiber of 4 cm in length;

35 warp yarns per centimeter;
24 wefts per centimeter.

The fabric is impregnated with the following bath and squeezed so far that about 90% of the Bath, calculated on the dry weight of the fabric:

To

Aqueous formaldehyde weight

(400 g per liter) 16 parts

Calcium chloride crystals
(CaCl ₂ · 2H ₂ O) 8 parts

Polyethylene emulsion 1 part

Water made up to 100 parts

The fabric is then ^{dried at 120 °} C. and ^{heated at 160 °} C. for 6 minutes. In comparison with the previously treated tissue, it shows a strongly

reduced change in dimensions and a greatly reduced water absorbency after the To wash.

Claims (6)

Patent claims: 1. Further development of the method according to patent application C 20 423 IVc / 8k (German Auslegeschrift 1 237 527) for reducing the water absorbency and for crease-proofing of cellulosic textiles by reaction with an aqueous solution of a metal salt and formaldehyde, whereby the material with the aqueous solution impregnated with a pH value of at least 5, then dried and heated, characterized in that the metal salt used is zinc sulfate or a salt of a metal of Group II of the Periodic System with a monobasic acid, which in normal aqueous solution at 18 ⁹ C to at least 50 <y _{0 is} ionized, with the exception of a magnesium halide, in an amount of 0. QQ3 gramol per 100 g of cellulose and a molar ratio of metal salt to formaldehyde of at least 1:17. 2. The method according to claim 1, characterized in that that the salt of an inorganic acid is used. 3. The method according to claim 1, characterized in that the salt of magnesium of an alkaline earth metal with an inorganic acid in a molar ratio of the salt to formaldehyde of at least 1:12 is used. 4. The method according to claim 1 to 3, characterized in that the metal salt is calcium chloride, bromide or iodide is used. 5. The method according to claim 3, characterized in that that magnesium nitrate or perehlorate is used as the metal salt. 6. The method according to claim 1 to 5, characterized in that the cellulosic textile material Cotton fibers or regenerated ceilu, lp.sefas, ern uses vyerden. Considered publications: German Patent Nos. 918 387, 936 325;
French patents nos. 877 371, 881 324, 547. 709 638 * 41 8.67 Bundesdruckerei Berlin