DE1276590B - Process for improving the crease, tear and abrasion resistance of cellulosic textiles - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

D06m

German class: 8 k- 1/40

Number: 1276 590

File number: P 12 76 590.1-43 (H 38613)

Filing date: February 10, 1960

Open date: September 5, 1968

It is already known to expose cellulosic textiles to the action of ionizing radiation. It is assumed that the irradiation changes the physical structure in two ways Way takes place, namely that an increase in strength is to be expected and that a chemical degradation of the Cellulose would use, so it is important to have a critical dose of irradiation find where the beneficial effects predominate. Experiments in this regard have shown that at the effect of a relatively high radiation dose on the cellulose-containing textile material is very strong Reduction in the degree of polymerization and thus practically destruction of the textile material occurs. When exposed to relatively low doses of radiation, the expected increase in strength cannot be determined will.

It has been found that an improvement in the crease resistance, tear resistance and abrasion resistance of cellulose-containing! Textile material is achieved by ionizing radiation, characterized in that a least 20%, preferably 30 to 40 ^o / o moisture exhibiting textile material in the absence REP is irradiated a modifying agent for cellulose with a total dose of 10 ³ to 2 ■ 10 "and or during irradiation Subsequently, by heating to at least 30 ° C., preferably 50 to 80 ° C., the carbon atoms of the molecular chains are crosslinked.

The cellulose-containing textile material treated according to the invention is in a conventional copper oxide ammonia solution insoluble, but still swellable and shows an increase compared to the untreated textile material the abrasion resistance with approximately the same tear resistance. For fine fabrics from relatively high-twisted yarns, such as voile and marquisette. which has a strong tendency to shrink shrink resistance against washing and thus good dimensional stabilization is achieved. These effects according to the invention are surprising methods for improving the wrinkle, Tear and abrasion resistance of cellulosic! Textile goods

Applicant:

Heberlein & Co. A. G., Wattwil (Switzerland)

Representative:

Dr.-Ing. P. K. Holzhäuser, patent attorney, 6050 Offenbach, Herrnstr. 37

Named as inventor:
Dr. Georg Heberlein,
Dr. Fritz Münzel, Wattwil (Switzerland)

Claimed priority:

Switzerland of May 21, 1959 (73 496),

dated September 7, 1959 (77 907), dated "December 7, 1959 (81541)

and are not to be expected by the person skilled in the art on the basis of the previous irradiation tests been. The method according to the invention is based on the following findings:

The decrease in the degree of polymerisation of cellulosic! Textile goods are based on the fact that the molecules are split when exposed to ionizing radiation. The following table 1 illustrates this reduction:

Tabel ! 1 Irradiated dose in roentgen Primary degradation in ""
immediately after irradiation 5 · 10 ^y 5 10 "' 8th 5 ⁵ 15th 10 « 25th 10 " 40

«W5M / 540

On the other hand, there is also a secondary degradation after the irradiation, which presumably is based on the fact that, upon irradiation in the presence of atmospheric oxygen, hydrogen peroxide groups which over time cause the molecular chains to break down. This secondary The following table 2 illustrates the dismantling:

Table 2

Total irradiated dose
in x-ray Secondary degradation in%
after days of irradiation
Days 3 5 10 .30 -40 - 1 8th 10 12th 13th 13th 5 -10 ⁴ 5 10 13th 15th 17th 17th 105 6th 12th 15th 20th 20th 21 5-1O ⁵ 7th 15th 20th 23 25th 25th 10 ⁶ 8th

In order to avoid excessive degradation of the cellulose, both the primary and the secondary degradation must be kept within acceptable limits. By irradiating a medium A strong primary degradation can be avoided up to a small radiation dose. But still the To achieve the desired crosslinking of the cellulose chains, the material is heated, being assumed is that the hydrogen oxide groups convert into radicals, which in turn by the The effects of heat react with one another and thus a crosslinking or crosslinking bridge formation between the carbon atom of the molecular chains. As a result of the networking that has taken place on the other hand, however, the secondary degradation of the cellulose is also avoided.

It has been shown that particularly favorable conditions for networking and a possible there is little degradation of cellulose if the cellulose-containing textile to be irradiated has a increased moisture content of at least 20%, preferably 30 to 40 ° / q, moisture. This measure is particularly effective when carrying out the irradiation in the presence of Air cheap.

The method according to the invention can be applied to all types of textile material, in particular flat structures, use. There are primarily woven, knitted or non-woven fabrics made from native cellulose such as Cotton or made of regenerated cellulose or such flat structures containing fibers made of natural and regenerated cellulose. The process can also be used on textile yarns, -use thread or twists.

The ionizing radiation is primarily gamma or X-ray radiation, but the effect according to the invention can also be achieved with the aid of beta rays. As a radiation source for the gamma radiation, for. B. Co ⁶⁰ , Cs ¹³⁷ or cleavage products of U ²³⁵ are used. The duration of the irradiation can be between 10 seconds and 4 hours, with a total dose between ΙΟ ³ and 10 ⁷ X-rays being irradiated. The irradiated textile material is preferably for a few seconds to a few minutes with the aid of. appropriately heated air or inert gases, steam or hot water. If the textile material is irradiated in the presence of air, it is expedient to heat it to 70 to 80 ^° C. If, on the other hand, the textile material is irradiated in the absence of air, e.g. B. takes place in a vacuum or in an inert gas, the heating temperature can be reduced ^{to 50 to 60 0C.}

It is also possible to carry out the irradiation and the heating of the textile material at the same time ίο and, if necessary, carry out post-heating at the same or different temperature. The reheating can take place immediately after the irradiation or even some time later take place, whereby the secondary dismantling must be taken into account.

The invention is explained in more detail using the following examples:

example 1

An imitation opeline with 36/19 threads per ¹ U French inch and the narrow yarn numbers 40/30 in warp and weft is singed, desized and bleached. Then it is subjected in the presence of air at 2O ⁰ C to the action of a gamma radiation source ⁽¹³⁷ Cs) for 15 seconds at 20 ⁰ C, so that a total dose of 0.25 ■ 10 ⁶ X into the tissue is irradiated. The .Gewebe is then by means of superheated steam for about 10 minutes to about

8O ⁰ C heated. The treated tissue is insoluble but still swellable in a conventional copper oxide ammonia solution. The tear strength, measured in the weft direction with a pendulum apparatus, is 20.8 kg per 2.5 cm strip width (22 kg for the untreated fabric). The abrasion resistance, measured with a test apparatus containing a disc rotating on the fabric surface and covered with a standardized woolen cloth, is 96,800 tours (13,800 tours for the untreated fabric). The average degree of polymerisation of the fabric decreased from 1500 to 1420 during the treatment.

Example 2

A conventionally pretreated mixed fabric, the warp and weft yarns of which consist of 70% cotton and 30% rayon, is ^{subjected to the action of a gamma radiation source (Co 00} ) in a vacuum for 3 hours, so that a total dose of about 2 × 10 ° X-rays are irradiated into the tissue. The fabric is then heated to about 55 ° C. for about 10 minutes by means of a stream of warm air. The treated tissue is insoluble but still swellable in a conventional copper oxide ammonia solution. Compared to the starting material, it has a greatly increased shear strength and an only insignificantly reduced tear strength.

B e i s ρ i e 1 3

Cotton full voile with 16/14 threads per 1/4 French inches and the narrow yarn numbers 100/2 and 100/2 in warp and weft is singed, desized and bleached. The tissue is then exposed to a gamma radiation source (Co ⁰⁰ ) for 3 hours in the presence of air at 20 "C, so that a total dose of 1.1 × 10" X-rays is irradiated into the tissue.

The fabric is then heated ^{to 60 °} C. for 5 minutes by means of a stream of warm air; after this treatment it is insoluble but still swellable in a conventional copper oxide ammonia solution.

Sections of the treated tissue as well as the untreated starting tissue have been measured, Subjected three times to a 30-minute hot wash with a soap solution, in a tension-free Condition dried and measured again, whereby the following results could be determined:

Treated
tissue

Shrinkage in the warp direction

Shrinkage in the weft direction

1.3%
1.3%

Untreated fabric

5%
9%

Example 4
Full cotton marquisette,

merges with

16/18 threads per> / - i French customs and the English Yarn numbers 100/2 and 100/2 in warp and weft are, as described in Example 3, irradiated and warmed.

Sections of the treated fabric as well as the untreated starting material are, as in Example 3 described, measured, washed, dried and measured again, with the following results be achieved:

exposed and irradiated a total dose of 6 ■ ⁵ x 10 in the tissue, then it is heated by means of a warm air flow for about 5 minutes at 8O ⁰ C. The treated fabric is insoluble, but still swellable in a conventional copper oxide ammonia solution and, compared with the starting material, has a greatly increased resistance to abrasion and only slightly reduced abrasion and only slightly reduced tear resistance.

Example 6

A conventionally pretreated cotton Renforce fabric, which has a moisture content of 40%, is ^{exposed to a gamma radiation source (Co 60} ) in the presence of air and a total dose of 8 · 10 ⁵ X-rays is irradiated into the fabric; it is then heated for 5 minutes by treatment in boiling water. After this treatment, the fabric is insoluble but still swellable in a conventional copper oxide ammonia solution and, compared to the starting material, has a greatly increased resistance to abrasion, with only a slightly reduced tear resistance.

Shrinkage in the warp direction

Shrinkage in the weft direction

Treated

tissue

2.1%
2.5%

Untreated fabric

35

12%
18%

40

Example 5

A conventionally pretreated cotton imitation poplin fabric, which has a moisture content of 35%, is exposed to a gamma radiation source (Co ⁶⁰ ) in the presence of air.

Claims (1)

Claim: Process to improve the crease, tear and abrasion resistance of cellulosic! Textile material by ionizing radiation, characterized in that textile material containing at least 20%, and preferably 30 to 40% moisture, is irradiated in the absence of a modifier for cellulose with a total dose of 10 ³ to 2 · 10 ⁶ REP and during the irradiation or subsequently through heating are cross-linked to at least 30 ⁰ C, preferably 50 to 8O ⁰ C, the carbon atoms of the molecular chains. Considered publications:
German Auslegeschrift No. 1042 521;
U.S. Patent No. 2,895,891;
Text. Res. Journ., 27 (1957), pp. 87 to 92
Chem. Zentralblatt, 1957, 8-8679). 809 599/540 p. 65 Q Bundesdruckerei Berlin