DE2749151A1 - Metallised high-shrinking fibres having low surface-resistance - produced by activating fibres with colloidal palladium soln. and chemically plating from alkaline bath - Google Patents

Abstract

High-shrinking, metallised filaments or fibres are produced by (a) activating high-shrinking filaments or fibres with a colloidal Pd soln. at room tepm. and then (b) treating with alkaline metal reducing baths at room temp. High-shrinking, metallised filaments or fibres obtd., having surface resistance max. 1 x 103 OMEGA, measured according to DIN 54345 at 50% RH and 23 degrees C, are claimed. The filaments and fibres are used for the prodn. of antistatically finished textile articles, and may be blended with other synthetic or natural fibres e.g. for floor covers, woven- or knitted fabrics. The surface resistance achieved are lower than those achieved on using ionogenic activating baths and acid metallising baths, e.g. 103 OMEGA compared with >106 OMEGA. Shrinking capacity is unimpaired by metallising. After shrinkage, surface resistance of fibres is hardly above that of the unshrunk fibres but at least 10x below that of C black-contg. fibres. On shrinking, textiles are free from dark stripes or mixt. effects.

Description

Metallized high-shrink threads and fibers

For a number of purposes, a fiber or thread material, which has a high conductivity was found to be desirable.

For example, such a material cannot be mixed with normal or only little conductive synthetic threads or fibers are processed in order to the electrostatic charging of the mixture or an article made from it to belittle.

For this purpose there are already carbon black fibers, metal fibers or Fibers the surface of which has been metallized have been proposed.

It has also already been proposed to incorporate such yarn and fiber mixtures to introduce such soot-containing fibers that are hochschruipfend to shrink from of these high-shrinkage types, the soot-containing dark fibers and threads in the finished article to make it visually disappear.

Metallized threads or fibers now have a lower surface resistance on as soot-containing and would thus be e.g.

even more suitable for this purpose.

The previously known method for the production of metallized Fibers with a firmly adhering metal layer, in particular due to electroless metal deposition however, there are several disadvantages. So they should, before the electroless metal deposition are subjected to de-oiling, etching or mechanical roughening. In the DT-OS 22 50 309 and 18 04 042 it is described that the Ätzvorbehandlun as it is with plastics known is essential because without etching pretreatment the adhesion resistance of the Metal layer on the fiber is degraded and it is impossible to have a metallized To obtain fiber of practical use value.

Furthermore, according to the known prior art, the fibers always with acidic ionic sensitization baths, e.g. acidic tin-II-chloride, sensitized and with acidic ionic activation baths, e.g. 3. Palladium chloride, at increased temperatures of 50 to 90 ° C activated to a subsequent metal deposition at elevated temperatures in acidic metallization baths, preferably at 75 ° C and higher with nickel or copper, especially the latter high temperatures during the metallization treatment do not allow high-shrinkage to produce metallized threads and fibers because of the comparatively high Temperatures of the shrinkage applied to the fibers already during the metallization treatment is triggered in whole or in part.

It has now been found that high-shrink threads and fibers with can be provided with an excellently adhering metal coating without a previous one Etching treatment is necessary when looking at the metal deposition after activation with colloidal systems. Here, in all sub-steps at temperatures be worked in which the threads or fibers to be metallized are not yet or shrink only to a very small extent.

The invention therefore relates to high-shrinkage metallized threads and fibers obtainable by treating them at room temperature with colloidal Palladium activated and the threads and fibers activated in this way at room temperature treated with alkaline metal reduction baths. High shrinkage is particularly preferred Threads or fibers made from acrylonitrile polymers with at least 40% by weight of acrylonitrile metallized according to the invention.

In principle, however, threads or fibers from thread-forming synthetic polymers such as polyamides, polyesters, polyalkylenes, polymodacrylics or polyvinyl halides are metallized according to the invention. Under shrinking According to the invention, threads and fibers are to be understood as meaning those whose heat shrinkage 10 to 70%, preferably 20 to 50%.

As the preferred acrylic fibers or threads according to the invention all such fibers are metallized after a dry spinning process or Wet spinning processes have been produced, preferably by the dry spinning process of acrylonitrile polymers from strongly polar organic solvents such as dimethylformamide, Dimethylacetamide or dimethyl sulfoxide.

Acrylonitrile polymers can be used for the production of synthetic Acrylic fibers known polymers are used. It is mainly to those substrates that are either 100% acrylonitrile or at least 85% by weight consist of acrylonitrile and also, for example, (meth) acrylates, vinyl carboxylates, (Meth) allyl carboxylates, (iso) butenyl carboxylates, maleinates, fumarates, (meth) acrylamides as well as N-substituted derivatives, vinyl ethers, styrene and derivatives, methacrylonitrile, also coloring additives, such as (meth) acrylic acid, itaconic acid, maleic acid, vinyl, (Meth) allyl styrenesulphonic acid, sulphoalkyl (meth) acrylates, vinyl (meth) allylphosphonic acid, Contain N-sulfoalkyl- (meth) -acrylamide.

It is of course also possible to use acrylonitrile copolymers, whose acrylonitrile content is far below 85% by weight, i.e. so-called modacrylics, e.g. from acrylonitrile and / or vinyl or vinylidene halide in amounts of 40 to 60% by weight.

The production of shrinking or highly shrinking threads and fibers is generally known and does not need to be explained in more detail here. E.g. the production of high-shrink acrylic fibers in DT-AS 16 60 328 and in the DT-OSes 25 04 079 and 25 04 080.

The individual metallization is as follows: Dem13 der DT-AS 11 97 720 becomes an activating solution of colloidal with tin-II salts Made of palladium.

The pH of the solution should always be ffi 1, and there should be an excess tin (II) ions are present.

The material to be activated is then with dwell times of a few seconds to a few minutes, for example 10 seconds to 2 minutes at room temperature treated in this activation bath. However, the treatment can take several minutes without any negative influences being ascertained.

The material activated in this way is then removed from the activation bath and rinsed with water, preferably at room temperature.

It has proven to be particularly beneficial to rinse as long as until the wash water reacts neutrally.

If necessary, the rinsing process is carried out in several stages.

Then the material treated in this way is for about 30 seconds to about Treated for 2 minutes in an acidic or alkaline medium at room temperature. In the case of the treatment in an acidic medium, the treatment in a 5 show sulfuric acid or approx. 20 show hydrochloric acid, which has proven to be excellent. Preferably however, the material is treated in an alkaline medium. Showed about 5 goat sodium hydroxide solution or about 10% strength by weight soda solution at preferably room temperature let best results.

The material is then placed in water, preferably at room temperature briefly rinsed, for example up to 30 seconds, to remove excess treatment medium to remove.

After this rinsing, the material is placed in at about 18 to about 30 OC an alkaline metal salt bath in which the metal precipitates on the property takes place.

Such metal salt baths are preferably baths of nickel salts, cobalt salts or their mixtures, copper salts, gold salts or other salts that are made up of let the alkaline baths precipitate.

Ammoniacal nickel baths are very particularly preferred according to the invention or alkaline soda copper baths are used. Mixtures can of course also be used from ammonia and caustic soda used to maintain the alkaline environment will.

Such metallization baths are used in the technology of electroless metal deposition known.

Baths of the following composition have proven to be particularly advantageous Proven: A nickel bath of 0.2 mol / l nickel-II chloride, 0.9 mol / l ammonium hydroxide (25 wt .-% solution), 0.2 mol / l sodium hypophosphite and enough ammonia that the pH value at 300C is 8.9 or a copper bath of 30 g / l copper (II) sulfate, 100 g / l Seignette salt and 50 ml / l 37% by weight formaldehyde solution. This copper bath is adjusted to a pH of 11 to 12 with sodium hydroxide.

The residence time of the material to be metallized in the metallization bath described depends on the desired metal layer cover on the surface of the goods. Preferably the dwell time is selected between 1 and 5 minutes. With a dwell time of Approx. 5 minutes, the deposited metal could be layered with a thickness of approx. Determine 0.2 pm.

Surprisingly, the metalization according to the invention, i. E. when using colloidal palladium activation solutions at room temperature, without prior degreasing, etching, roughening or other pretreatment, and using alkaline metallization baths at room temperature on the metallized fiber material which are powers of ten lower than that when using achievable by ionic activation baths and acidic metallization baths.

According to the invention, therefore, metallized threads and fibers can be produced whose surface resistance, measured according to DIN 54345, at 50% r.h. and 230C is max. 1 x 103 r, while metallized threads and fibers are those made from ionogenic Activation baths and acidic metallization baths have been metallized, surface resistances of about 106 and above.

It has been found to be particularly surprising and advantageous that the filaments and fibers metallized according to the invention hardly have any shrinkage properties are significantly lower than before the metallization. Even after the trip After shrinkage, the surface resistance of the threads and fibers is hardly higher than that Original value in the untrumped state, but with a few powers of ten below that of threads and fibers containing carbon black.

The high shrinkage metallized fibers of the invention and Threads are ideal for mixed processing with other fibers or threads another synthetic or native material, e.g. polyamide, polyester, polyalkylene, Poly (mod) acrylics, cotton or wool, for the production of textile fabrics, such as textile floor coverings, woven or knitted goods that are sufficient for practical use Have antistatic.

By shrinking out the metallized high-shrinkage ends according to the invention Fibers in the textile article, as e.g.

when dyeing the piece or when cooking, steaming, printing, latexing and other heat treatments happens, the proportions of the invention are withdrawn Fiber back into the piece of textile so that there is practically no streaking of dark spots or melange effects occur.

The admixture is preferably carried out in amounts of 0.1 to 20 Cew.-X, based on the total mixture.

Example 1 Staple fibers made from an acrylonitrile polymer dtex 5.0 / 110 mm cutting length (94% acrylonitrile, 5.5 X methyl acrylate, 0.5 X sodium methallyl sulfonate) with a boiling shrinkage of 32.7 X are placed in a hydrochloric acid bath at room temperature immersed in a colloidal palladium solution at pH 1 according to DT-PS 1 197 720. To Linger with a slight movement of the bath or goods for between 30 seconds and 2 minutes the staple fibers rinsed with water. Then they were placed in a 5% sodium hydroxide solution at room temperature with slight movement of goods.

After treatment for 30 seconds to 2 minutes, the staple fibers became rinsed with water. They were then placed in an alkaline nickel salt solution at room temperature. This solution had the following composition: 0.2 mol / l nickel-II-chloride, 0.9 mol / l ammonium hydroxide, 0.2 mol / l sodium hypophosphite (pH 8.9 and 23 0C) To about 15 sec. the surface of the staple fibers began to turn dark. To The fibers were warped with a fine layer of nickel metal for about 30 seconds.

After about 5 minutes a nickel layer of about 0.2 nm was on the surface deposited the staple fiber. After removing it from the nickel bath, it was rinsed Fiber thoroughly up to a neutral reaction of the washing water.

The surface resistance according to DIN 54345 at 23 ° C and 50% r.h. measured in ohms was 2. lolil, after a blind dyeing 1 # 103 #, after a blind dyeing and a laundry 1 # 104 #. The boiling shrinkage of the nickel-plated fiber was 31.0%.

Example 2 A knitted fabric made from a fiber yarn made from an acrylonitrile polymer (94 X acrylonitrile, 5.5% methyl acrylate, 0.5% sodium methallyl sulfonate), Yarn no. Nm 25.2 / 1 of the raw yarn (the cooking shrinkage of the raw yarn was 37.9%) at room temperature in a hydrochloric acid bath of a colloidal palladium solution at pH 1 immersed in accordance with DT-PS 1 197 720. After lingering with a slight movement of bath or goods the knitted fabric was rinsed with water for between 30 seconds and 2 minutes. Then one gave it in a 5% sodium hydroxide solution at room temperature with gentle movement of the goods.

After a treatment of 30 seconds to 2 minutes, the knitted fabric was with Rinsed with water. It was then added to an alkaline nickel salt solution Room temperature according to example 1.

After 5 minutes a nickel layer of about 0.2 µm was on the surface the remaining elastic knitted fabric deposited.

After removal from the nickel bath, the trick is split thoroughly with water until the washing water reacts neutral and dried.

The surface resistance of the knitted fabric according to DIN 54 345 at 23 ° C and 50 X r.F. was 4. 101 ohms.

The boiling shrinkage of the nickel-plated raw yarn was 35.1%.

The resistance of the thread to be pulled out when pulling out the severable knitted piece was 1.6-10 cN before nickel plating.

After 5 minutes of nickel plating, the resistance was 2.8-15 cN. So you can practically not tear the knitted piece with the same force and wind up the nickel-plated, shrinkable thread, so that it can be used for other purposes to use.

Bl ind staining The metallized, high-shrinkage samples are given in a vessel with acetic acid, which has a pH of 4.8.

Then the acetic acid with the sample is heated to boiling, whereby the shrinkage is triggered. Cook for an hour from the start of boiling. It is then allowed to cool, the sample is removed, rinsed with water, dried and measured the change in the surface resistance ohms according to DIN 54 345.

Washing The metallized sample is placed in a vessel containing 5 g / l emulsifier contains in water and washes at 30 OC for 30 min.

long in a washing machine. After washing, drying and air conditioning at 23 OC and 50% r.h. the surface resistance of the sample is measured.

Boiling shrinkage To determine the boiling shrinkage, 20 individual capillaries are used attached at the ends with clamps and hung vertically, the capillary length is determined. After that, they are immersed in boiling water for ten minutes, dried and then measured their length again in a normal climate. The difference between the initial and final length is set as a percentage of the initial length. The measurement is carried out and averaged ten times.

Another common way to measure shrinkage is by cooking a 12 g heavy shrink strand in water. Proceed as follows: Man exhibits a skein of yarn high-shrinkage, synthetic fibers, in this case from high-shrinkage polyacrylonitrile fibers. The length of this So-called. Shrink strand is measured by placing the strand with a 2 kg weight loaded and determines the length. The shrink strand is then boiled for 30 minutes at 95-98 ° C in water, then allowed to cool in this water to 30-40 ° C, takes out and dry. The now shrunk strand is then used again Loaded 2 kg and measured the length. The difference between non-shrunk and the shrunk strand gives, expressed in%, the yarn shrinkage of the metallized Yarn on formula LA - LK Carnschrumpf% = ~~~~~~~~. 100 LA LA = clear width of the Strand before shrinking LK = inside width of the strand after shrinking

Claims (5)

Claims 1. Highly shrinking, metallized threads or fibers. 2. Highly shrinking, metallized threads or fibers with a surface resistance, measured according to DIN 54345 at 50, r. F. and 23 OC of a maximum of 1 x 103.. 3. Highly shrinking, metallized threads or fibers, thus obtainable, that you can high-shrink threads or fibers at room temperature with a colloidal Palladium solution activated and the threads and fibers activated in this way at room temperature treated with alkaline metal reduction baths. 4. Process for the production of high-shrink, metallized Threads or fibers, characterized in that high-shrinkage threads or fibers are used activated at room temperature with a colloidal palladium solution and the activated in this way Threads and fibers treated with alkaline metal reduction baths at room temperature. 5. Use of high-shrink, metallized threads and fibers according to responses 1 to 3 for the production of antistatic textiles Articles.