DE2023527B2 - FIBERS AND FEDES MADE OF POLYAETHYLENE TEREPHTHALATE MODIFIED WITH 2.2DIMETHYLPROPANEDIOL-1,3 - Google Patents

Description

a) a shrinkage capacity in warm to boiling water, which shows the shrinkage values that on the continuous shrinkage-temperature curve running through the following points lie, does not exceed:

15th

about 0% at 40 ^c C,

1% at 50 ^c C,

2.7 _% at 60 ⁰ C,

5.5 ° / above at 70 ⁰ C,

9.5% at 8O ⁰ C,

13.8% at 9O ⁰ C,

20 ° / ₀ at 100 ° C,

b) a shrinkage capacity in a hot gas atmosphere, in particular hot air, which is within the range defined by the points

about 0% at 80 ° C, 4.2% at 100 ⁰ C, 11% at 120 ⁰ C, 19.5% at 14O ⁰ C, 29% at 16O ⁰ C, 41% at 18O ⁰ C, 60% at 200 ⁰ C,

as well as by the points

about 0% at 130 ^c C,

1.5% at 14O ⁰ C,

7% at 16O ⁰ C, 12% at 18O ⁰ C, 20% at 200 ° C

running two continuous curves is limited.

2. Fibers and threads according to claim 1, characterized by a shrinkage capacity in warm until boiling water, which is not greater than the shrinkage values indicated by the following Points along the continuous shrinkage temperature curve are:

about 0% at 40 ^c C,

0.1% at 50 ⁰ C,

0.3% at 6O ⁰ C,

0.6% at 7O ⁰ C,

0.9% at 8O ⁰ C,

1.4% at 90 ⁰ C,

2.2% at 100 ⁰ C.

3. fibers and threads according to claim 1 and 2, characterized by a shrinkage capacity in hot gas atmosphere, in particular hot air, which is within the range of the through the points

about 0% at 90 ° C,

2% at 100 ⁰ C,

7.1% at 120 ⁰ C,
14.5% at 140 ° C,
22.5% at 160 ⁰ C,
33% at 180 ⁰ C,
45% at 200 ^° C

as well as by the points

about 0% at 110 ⁰ C,

2% at 120 ⁰ C.

8% at 140 ° C,
15.3% at 160 ⁰ C,
24.5% at 180 ⁰ C,
35% at 200 ° C

running two continuous curves is limited.

25 It is known to produce yarns and fabrics of fibers and filaments having different shrinkability. When the shrinkage is triggered by a chemical or thermal treatment, the more strongly shrinking fiber or thread type then causes the weaker or not at all shrinking component to form arches and crimps. This gives the corresponding yarn or textile a certain voluminosity, which is very desirable for numerous purposes.

The previously known polyester fibers with a significantly higher shrinkage capacity than the normal types (referred to here as polyester high-shrinkage fibers) also have a comparatively high shrinkage value in boiling water, over 20%, or they shrink completely at temperatures around 100 ^° C. Since the absorption capacity for disperse dyes is insufficient at lower temperatures, dyeing must be carried out in the temperature range of boiling water or even above, so that in yarns and textiles which contain the above-mentioned high-shrinkage fibers in a mixture with non-shrinking or less shrinking fibers, after the dyeing process at elevated temperature no longer sufficient volume can be generated. However, this is very desirable with a view to lending textiles made of different colored polyester fibers and threads a voluminous character at will. There is therefore a need for polyester fibers which do not shrink or shrink only very little during dyeing, but which shrink considerably at higher temperatures.

There were now fibers and threads made with 2,2-dimethylpropanediol-1,3 modified polyethylene terephthalate containing 1 to 20 percent by weight, preferably 3 to 7 percent by weight, dimethylpropylene units (based on the polyester) found the are characterized by a shrinkage capacity in warm or boiling water, which is not is higher than curve 1 in FIG. 1 shows (boiling shrinkage 20%), as well as a shrinkage capacity in a hot gas atmosphere, preferably in hot

air, which by the curves 3 and 3 'in FIG. 2 enclosed area (20 to 60% at 200 ⁰ C) is shown, in particular these fibers and threads are characterized by a shrinkage capacity in warm to boiling water, which is not higher than curve 2 in F i g. 1 (boiling shrinkage 2 ⁰ J ₀ ) as well as a shrinkage capacity in a hot gas atmosphere, which is within the range indicated by curves 4 and 4 'in FIG. 2 enclosed area (35 to 45 ° / ₀ at 200 ⁰ C) and which preferably corresponds to the optimal curve 5 in the same figure (hot air shrinkage at 200 ⁰ C 40%).

German Offenlegungsschrift 1,495,625 already discloses that fibers and threads made of polyethylene terephthalate modified with 2,2-dimethylpropane-1,3-diol and containing 1 to 20% (based on the polyester) dimethylpropylene units have valuable high-shrinkage properties. It is also known that such fibers may be shrunk after dyeing upon heating to 18O ⁰ C again. What is not known, however, is that the copolyesters mentioned can be used to produce fibers and threads which satisfy the properties expressed in the curves given above, in particular have no or only a very low boiling shrinkage, but are subsequently able to shrink sharply in a hot gas atmosphere. It was surprising that this aim can be achieved by a simple heat treatment of the drawn filaments made of polyethylene terephthalate of the above-mentioned composition modified with 2,2-dimethylpropanediol-1,3; this changes the rise in the shrinkage temperature curve. For example, this can be done by moistening the drawn threads with water or steam and, without allowing shrinkage, ^{drying them at temperatures between 80 and 160 °} C., or by additionally drying the threads thus dried to a temperature between 120 and 140 without tension ° C heated. While this can greatly reduce the shrinkage in boiling water, it ^{only decreases slightly at temperatures of, for example, 180 to 210 °} C. in air. For the production of staple fibers according to the invention, the heat treatment is carried out on drawn fiber cables, which are then crimped and cut.

The fibers and threads according to the invention are distinguished by a shrinkage capacity in warm or boiling water which is not higher than from curve 1 in FIG. 1 can be seen. In Fig. 1, the shrinkage of the threads or fibers is plotted on the ordinate as a percentage of the initial length before shrinking. The values for the shrinkage temperature are found on the abscissa in ⁰ C. The shock shrinkage is determined for all measurements, ie that shrinkage which is achieved on immersion in water at the specified temperature. The samples are immersed in the water for 5 minutes. The boiling shrinkage, ie shrinkage at the temperature of the boiling water, of the threads and fibers according to the invention is a maximum of 20%. In a preferred embodiment, the threads and fibers according to the invention have a shrinkage capacity which is not higher than curve 2 in FIG. 1 indicates. Despite this relatively low boiling shrinkage of up to 20%, the threads and fibers according to the invention have a considerable shrinkage capacity in a hot gas atmosphere, preferably in hot air.

This shrinkage capacity lies in that of curves 3 and 3 'in FIG. 2 enclosed area. In Fig. 2, the percentage shrinkage of the threads and fibers according to the invention is plotted on the ordinate, and the corresponding temperature of the hot air in ⁰ C is plotted on the abscissa. The shrinkage takes place by suddenly introducing the threads and fibers into an air space preheated to the appropriate temperature, the heat capacity of which is so great that

ίο the temperature by introducing the threads and Fibers is not significantly reduced.

The fibers and threads produced in this way can be made in any presentation at the boiling temperature of the water, e.g. B. as flake, sliver or yarn, dyed and then, together with other dyed, already shrunk known fibers and threads, processed into a fabric. Fibers and threads known as such can be used in addition to polyester fibers, such as fibers made of polyamide, polyacrylonitrile, cellulose. In fabrics produced in this way, the desired volume is then produced by a hot air treatment in that the fibers produced according to the invention contract and the fibers that have already been shrunk are caused to form arches and crimps. It has proven to be particularly advantageous that the shrinking process can be carried out in several stages; so it is B. possible to dry the fabric at 140 ⁰ C and then to heat set at 180 to 190 ^{0 C.} During the drying process, the fabric is pre-compressed and during the heat-setting process, the final compression takes place. This achieves a particularly smooth appearance of the goods which, for example, cannot be achieved using polyester high-shrink fibers made from unmodified polyethylene terephthalate as a result of shock-like shrinkage initiation, but rather has undesirable cracks. Another advantage of the polyester high-shrinkage fibers according to the invention is that yarns which contain these fibrous materials can be steamed in the weaving preparation to calm the twist without the fear of blocking the shrinkage in a hot gas atmosphere. Also to be mentioned as advantageous are the better dyeability mentioned in German laid-open specification 1 494 625, the advantageous handle and a pronounced lack of pill.

The method is described as follows and explained using exemplary embodiments.

Preparation of the spinning material

200 kg of a copolyester of terephthalic acid, ethylene glycol and 2,2-dimethylpropanediol-1,3 containing 5% dimethylpropylene units become through from the melt after drying a spinneret with 90 bores each 0.5 mm in diameter with a delivery of 135 g / min and spun at a take-off of 1400 m / min. 1500 of these filaments are combined into a cable and stretched this in steam in a ratio of 1: 3.7.

example 1

That drawn tow prepared as above is guided between two run at the same speed rolling units through a heated to 14O ⁰ C air section with a residence time of 3.5 seconds. Then it is curled and cut. The following values were determined on the fiber: Tear strength

32p / dtex, elongation at break 11%, boiling shrinkage 20%, Thermal shrinkage in air at 200 ° C 45%.

Example 2

The drawn cable is dried on heated drums at 100 ° C., residence time 16 seconds, and then curled and cut. Fiber values: tensile strength 32 p / dtex, elongation at break 22%, heat shrinkage 5%, thermal shrinkage in air at 200 ° C 45%

Example 3

The drawn cable is dried on hot drums at 80 ° C. with a residence time of 2 seconds and ruffled. It is then heated in a heated steam pipe for 60 seconds at 130 ° C and cuts as usual. Fiber values: tensile strength 29 p / dtex, elongation at break 35%, boiling shrinkage 1.5%, Thermal shrinkage in air at 200 ° C 42%.

Example 4

The procedure is as described in Example 2, but heating the crimped tow in a heated steam pipe 60 seconds on 13O ⁰ C. fiber values: tensile strength 37 p / dtex, elongation 33%, boiling water shrinkage 0.4%, heat shrinkage in air at 200 ° C 45 % ·

Technical progress

The improvement in the shrinkage behavior of the fibers and threads according to the application compared the threads according to the closest prior art (German Auslegeschrift 1 495 625, example 2) is illustrated by the following comparison.

Comparison of the examples of the present application with example 2 of German Auslegeschrift 1,495,625

Present registration Further treatment of the drawn threads a cook
shrink Thermal shrinkage example 1 3.5 seconds through an air gap of 140 ° C 20% 45% (without approval of shrinkage) (Air at 200 ° C) Example 2 16 seconds on a drying drum at 100 ° C 5% 45% (Air at 200 ⁰ C) Example 3 2 seconds on drums heated to 80 ° C, 1.5% 42% then 60 seconds in steam pipe of 13O ⁰ C (Air at 200 ° C) Example 4 3.5 seconds through an air gap of 140 ⁰ C, 0.4% 45% then 60 seconds in a steam tube at 160 ° C (Air at 200 ⁰ C) German interpretation font 1 495 625 Example 2 48% 65% (Air at 180 ° C)

1 sheet of drawings

Claims (1)

Patent claims: 1. Fibers and threads made with 2,2-Dimethylpropanediol-1,3 modified polyethylene terephthalate containing 1 to 20, preferably 3 to 7 percent by weight, based on the polyester, dimethylpropylene units, characterized by