US2938815A - Process for making cellulose materials rotproof - Google Patents

Description

United States Patent PROCESS F OR MAKING CELLULOSE MATERIALS ROTPROOF Cornelis van Bochove, The Hague, and Hendrik J. Hueck,

Delfgauw, Netherlands, assignors to Nederlandse 0rganisatie voor Toegepast-Natuurwetenschappelijk 0nderzoek ten behoeve van Nijverheid, Handel en Verkeer, The Hague, Netherlands No Drawing. Filed June 30, 1958, Ser. No. 745,326

Claims priority, application Netherlands July 4, 1957 5 Claims. (Cl. 117-1385) It has been found that cellulose materials such as cotton can be protected against rotting by treating them with chloracetamide and formaldehyde in a molar ratio of 1 mol chloracetamide on not more than 1 mol formaldehyde; instead of this the material can also be treated with methylolchloracetamide.

The effect is specific; only instead of chloracetamide, bromacetamide or iodoacetamide may be used, but for practical purposes this is unnecessarily expensive. With other halogen carboxylic acid amides one does not nearly obtain the same effect as with chloracetamide. The same holds good for the unsubstituted acid amides. The methylol compounds of the following materials have been examined for example:

Acetamide Butyramide Capronamide Beta-chloropropionamide Dichloracetamide but the effect found, if any, was negligible. Neither did a treatment with formaldehyde only, yield a rotproof product.

As it is suflicient for the reaction when one mol of formaldehyde is present per mol of chloracetamide, and an excess of formaldehyde therefore not only means a waste but may moreover be detrimental not more than one mol of formaldehyde should be present per mol of halogen acetamide. By formaldehyde is also meant a material yielding formaldehyde such as paraldehyde.

The invention will be illustrated with regard to the treatment of cotton; the protection of cotton against rotting is namely very important and therefore this treatment has been subjected to the most detailed examinatron.

The particulars given below are obtained with the following materials:

In impregnating a foulard was used:

Fabric speed: 0.7 m./min.;

Squeezing pressure: 350 kg. across 28 cm. fabric width 65 Squeezing yield: about 60%.

2,938,815 Patented May 31, 1960 lCC The drying and after-heating took place following circumstances:

Drying temperature: C.;

Drying time: 10 min.;

Temperature during after-treatment: see below; Time: 4 /2 min.

In order entirely to remove material which might not have reacted, the foulard was rinsed a few times'with cold water first, and afterwards twice with water. of 70 C.

The burying tests and the tensile strengths were determined according to instruction Vitno-Bio Al.

The treatment is carried out as follows by way of example.

The cotton was impregnated with a solution of methylolchloracetamide in water to which a catalyst was added (e.g. oxalic acid). temperature (130140) followed which lasted a few minutes, and during which the reaction proper took place. After this rinsing was effected.

The cotton treated in this way was subjected to a burying test. After 1, 2 and 4 weeks a number of strips was removed and the tensile strength determined. As a criterion for the behaviour in the ground the rest strength was taken. The definition of rest strength is as follows: the ratio between the tensile strengths after and before the burying, expressed in percents.

The results of a number of these experiments was as follows:

Table 1.--Results of burying tests of cotton, treated with methylolchloracetamide under the blank rest strength (percent) Degree tensile after- Test No. of substistrength tution l (kg/25 mm.) 1 week 2 weeks lweeks 1 Expressed in the number of side groups per 100 glucose units.

From these results it can be concluded that there is an evident correlation between the degree of substitution and the resistance against the influence of micro-organisms. Complete resistance for four weeks of burial is obtained at a substitution degree of about 6. When one week of burial is chosen as a criterion, a substitution degree of l to 2 is sufiicient. These degrees of substitution are extraordinarily low, as compared to other methods for making cellulose material rotproof by chemical modification, such as acetylating and cyanoethylating, in which at least /3 of the total number of OH- groups of the cellulose should be replaced to ensure success, which, however, implies a drastic change of the qualities. The effect at the above-mentioned very low degrees of substitution is strictly specific of the process according to the invention.

Besides a burying test a few samples of treated cotton were subjected to a treatment with enzyme solution for two weeks.

After drying a treatment at a higher "chloracetamide respectively in water.

test.

The results of this can be summarized as follows: Table 2.-Cotton treated with methylolchloracetamide ,For purposes of comparison the results after 1 weeks burial have been inserted in this table. V

1 In this test too it appeared, that the cotton is made re-' sisteut by the reaction with methylolchloracetamide. The

results of this test correspond more or less to those of 1 Weeks burial.

As a matter of course'one is neither bound to the above-mentioned specifications of the fabric, nor to the details of impregnating, .drying and after-treatment.

In order to obtain more certainty about the efiect of the bonded chloracetamide, examination was made, as to what influence loosely applied chloracetamide had on the resistance of cotton. To this end cotton was impregnated with solutions of chloracetamide and methylol- Both compounds were applied to the fabric in various concentrations, which corresponded more or less to the quantity of bonded chloracetamide.

The impregnated fabrics were subjected to a burying Results: I

Table 3.Comparison of "bonded and loose methylj It is clear that "loose" chloracetamide has hardly any efiect at all.

The influence of the variables in the process according to the invention was further examined.

During the reaction of celloluse with methylolchloracetamide the following variables occur:

' (1) Concentration of methylolchloracetamide in the impregnating liquid;

(2) Nature and quantity of the catalyst used.

(3) Temperature and duration of the after-heating. In this reaction the quantity of bonded chloracetamide is a criterion for the degree of conversion. Besides that, this kind of reactions requires that the mechanical properties of the cotton may not be subject to any or scarcely to any alterations. A criterion for this is V the tensile st e investigation was now made as to what influence some of the above-mentioned variables had on the attained degree of substitution and on the loss of tensile strength. (1) Influence of the concentrationof the methylolchloracetamide. p

A series of tests was carried out, in which a cotton was impregnated with solutions of methylolchloracetamide in water with'a content varying from 2 to 20%.

The results are given in Table 4.

Table 4.--Connection between bath concentration and degree of substitution and tensile strength Reaction conditions:

pH of the impregnating bath: 2.5 Catalyst: oxalic acid Drying at 70-80 C. After-heating: 5 min. at 140 C.

. .Methylol Degree of Tensile Loss 01 Test No. chloracetsubstistrength tensile; amide tution, (kg/25 strength, (percent) percent mm percent (2) Influence of nature and quantity of the catalyst used and of the temperature of after-heating. Oxalic acid was chosen for a catalyst.

With oxalic acid as a catalyst the pH was adjusted to 4.5 and 2.5. Besides this a test was carried out with a pH of 6.5, which was obtained by adding a few drops of NaOH to a solution of methylolchloracetamide, which in itself had a pH of about 5.5. So here no oxalic acid was added.

The results are given in Table 5.

Table 5.Influence of the pH of the impregnating bath and the reaction temperature on the degree of substitution Reaction conditions:

Bath concentration 16.7%, V After-heating at and C. respectively for 5 minutes.

Tempem- Degree 0! Loss of Test No. pH -ture substltensile 0.) tution, strength,

percent percent From all these tests it is evident, that by the treatment according to the invention a product is obtained which is extremely rotproof.

Some tests were carried out in order to compare the present process with known processes.

(l) Influence of repeated washing and dry-cleaning on the rotproofness of cotton, treated in the following ways:

(a) According to the invention (substitution degree 6;

of. Table I);

(b) Copper naphthenate (approx. 0.7% Cu); (0) Lauryl-pentachlorophenol (+water repellent agent) (approx. 2%).

These three samples were washed 5 times and drycleaned 5 times. Both treatments were carried out in a conventional domestic washing machine manufactured by the Allgemeine Elektrizitats Gesellschaft, a well known manufacturing firm of West Germany.

For the washing the washing agent Savonine Compleet was used. Savonine Compleet stands for a detergent of the following composition in percent by weight: common soap 20%; sodium carbonate anhydrous 45%; sodium meta silicate 91-1 0 12%; .sodium salt of carboxy methyl cellulose (NaGMC)...1.2%;..the: rest.wa-

ter. This preparation was applied in a quantity of g./litre. The weight ratio of dry sample to bath liquid was 1:20. The washing took place for one quarter of an hour at 80 C. After this rinsing in distilled water took place twice, each time for 5 minutes, and drying at 60 C.

Dry-cleaning took place in trichloroethylene at 20 C. for 10 minutes. After this drying at the air took place.

After the termination of the washing tests the samples were subjected to a burying test for two and four weeks.

In Table 6 below is indicated what procentual rest strengths the strips had that had been buried.

From this the following is apparent:

Washing and dry-cleaning have only very little influence on the rotproofness of cotton which has been treated according to the invention.

Cotton treated with copper naphthenate will stand dr cleaning, but does not stand washing quite as well.

The etfect of lauryl-pentachlorophenol disappears entirely, both by dry-cleaning and by washing.

These results clearly show the difference between the effect of chemical reaction with the cellulose according to the invention and the effect of impregnating loosely with the usual fungicides.

Some exposition tests were also carried out.

On the roof of a building a comparative test was carried out in a number of racks, in which a number of cotton strips, which had been treated in various ways, were exposed to the sunlight. In this test one half of the strips was put behind frames of Plexiglas, by which the influence of the sunlight was not eliminated, but that of the rain was.

After the termination of the exposition (1, 2, 4 and 8 months) a certain number of the strips were subjected to a burying test (2 weeks).

The following treatments were applied:

(a) Treatment according to the invention (degree of substitution 6);

(b) Treatment with copper naphthenate (0.8% Cu);

(c) Treatment with lauryl-pentachlorophenol+Water repellent agent;

(d) Treatment with copper-S-oxyquinoline (0.7% Cu).

In the following Table 7 the rest strengths (in percents of the non-buried samples) are again given.

From these results it is evident that cotton treated according to the invention, when exposed to atmospheric influences, is much slower to lose its rot-preventing qualities than cotton which has been impregnated according to the usual processes. This should be ascribed to the chemical reaction which has taken place when treating it with methylolchloracetamide.

What we claim is:

1. Process for improving the resistance against microbiological attack of cellulose-containing materials by impregnating the material with an aqueous solution of halogeno-acetamide and formaldehyde and an acid catalyst, the amount of formaldehyde being not greater than one mole per mole of halogeno-acetamide, drying the impregnated material and subjecting it to a temperature References Cited in the file of this patent UNITED STATES PATENTS 2,270,520 Riehen I an. 20, 1942 2,446,864 Abrams Aug. 10, 1948 2,587,957 Bauer et al Mar. 4, 1952 FOREIGN PATENTS 495,714 Great Britain Nov. 14, 1938

Claims (1)

1. PROCESS OF IMPROVING THE RESISTANCE AGAINST MICROBIOLOGICAL ATTACK OF CELLULOSE-CONTAINING MATERIALS BY IMPREGNATING THE MATERIAL WITH AN AQUEOUS SOLUTION OF HALOGENO-ACETAMIDE AND FORMALDEHYDE AND ACID CATALYST, THE AMOUNT OF FORMALDEHYDE BEING NOT GREATER THAN ONE MOLE PER MOLE OF HALOGENO-ACETAMIDE, DRYING THE IMPREGNATED MATERIAL AND SUBJECTING IT TO A TEMPERATURE OF BETWEEN 110 AND 160*C.