DE1228025B - Manufacture of threads from linear polyesters - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

DOIf

German class: 29 b - 3/60

Number: 1228 025

File number: P 30395IV c / 29 b

Filing date: October 18, 1962

Open date: November 3, 1966

One known way of obtaining antistatic fibers is by spinning copolymers. Hydrophilic monomers are in the macromolecular chain by polymerization with a greater proportion of hydrophobic monomers combined. In some cases you have to some extent found useful copolymer compositions, but it did so at the cost of deteriorating physical properties such as strength, elongation, stiffness, durability, alkali resistance.

The invention aims to develop an oriented, synthetic, melt-spun fiber which has essentially antistatic properties. The fiber can also be due to cavities have a high covering power in connection with a glossy surface.

The subject of the invention is a method for producing threads from linear polyesters, in which at least 75% of the repeating units of the polyester chain are at least one divalent carbocyclic Contain a ring with at least 6 carbon atoms as an integral part of the polyester chain, wherein between the two binding sites of the ring to the polyester chain at least 4 ring carbon atoms are located. The method according to the invention is characterized in that a melt of the polyester, which additionally contains a polymeric alkylene ether with a molecular weight contains at least 1300 in amounts of 3 to 15 percent by weight evenly as a separate phase, spun.

The polymeric alkylene ethers are either ethylene oxide, propylene oxide or ethylene oxide-propylene oxide condensation products. The polymeric alkylene ether is preferably a polyethylene oxide which has no more than one hydroxyl group at the ends and is capped by one or more ether end groups of the formula -OR, where R is Is alkyl, aryl or aralkyl group.

Thorough mixing is essential to maintain the polyether compound to distribute sufficiently evenly in the hydrophobic polycondensate. Usually it is enough to put the components in a screw press to melt, although due to the high melt viscosity of the polycondensate and the polymer Alkylene ethers mechanically operating mixers are even more effective.

X-ray images of polyethylene terephthalate threads modified with high molecular weight polyether show features that are characteristic of an oriented crystalline polyether glycol phase, except-

Manufacture of threads from linear polyesters

Applicant:

E. I. du Pont de Nemours and Company,

Wilmington, Del. (V. St. A.)

Representative:

Dr.-Ing. W. Abitz, patent attorney,

Munich 27, Pienzenauer Str. 28

Named as inventor:

Eugene Edward Magat, Spring Valley, Del .;

William Henry Sharkey,

Wilmington, Del. (V. St. A.)

Claimed priority:
V. St. v. America October 20, 1961
(146424)

the features characteristic of an oriented crystalline polyethylene terephthalate phase. In contrast, a terephthalate polyester, which contains polyethylene units in the chain, as described by D. Coleman in J. Polymer Sci., p. 14, (1954), no difference from radiograms of the modified polymer, which both polyethylene terephthalate and polyether terephthalate blocks contains, and the unmodified polyethylene terephthalate.

From the German Äuslegeschrift 1 000 778 there is a method for changing the surface structure of polyester fibers with aqueous solutions of alkali metal hydroxides known, which consists in that polyglycols or their derivatives are added to the solutions. This known method has the Purpose to polyester fabrics in terms of their crease, their feel and their dyeability refine. This type of finishing relies on moderate fiber degradation and was previously made by bare The fibers are boiled with 4 to 20% alkali. Here, however, the difficulty arose

609 709/304

rigkeit that at low alkali hydroxide concentrations the desired effect occurred only after very long treatment times, while alkali hydroxide concentrations were too high led to fiber damage. By adding polyglycols to Alkali according to the German Auslegeschrift 1000 778 succeeds in the desired finishing "the To bring about polyester fabric nicely with decoction baths, which contain less than 4% alkali hydroxide, and thereby avoid damaging the fibers.

However, the treatment of polyester fabrics by the known method cannot Achieve permanent antistatic effect, because the polyglycols used only for surface treatment are water-soluble and can therefore be easily 'washed out' of the "fabric" when it is washed. On the other hand can have an antistatic effect, even if it is obtained by boiling the fabric with alkali with added of polyglycols should also not be permanent because they only affect the fiber surface applied polyglycols are removed from the fabric during its 'normal use' by abrasion will. ·. '. .

By contrast, the method according to the invention achieves a lasting antistatic effect because the polymeric alkylene ether responsible for this effect in .Smelt spinning evenly in the fibers are stored and consequently neither leached out of the fibers by washing nor through Abrasion can be removed from them.

The stated tendency of the fabric to generate static electricity is given as the traction current resistance in ohms / unit area (the unit of area is insignificant here). - This value is determined according to the A / ATCC method, C-76-59, parallel to the fabric surface at the specified temperature and humidity. The numerical values are given as »log R« , ie the decadic logarithm of the resistance in ohms. High values indicate the tendency to take up and retain a static charge. Adequate antistatic protection is achieved when the behavior of the cotton is achieved; log R for cotton is 13.1 at 30% relative humidity.

Of the. Washing test, which serves to imitate home washing, is carried out as follows: The fabrics. are ^: washed in a drum washing machine at a water temperature of 38 ° C; the washed fabrics are squeezed to remove excess water and then drum dried at 77 ° C. -

"Average molecular weight" is to be understood here as the number average molecular weight.

The expression "stable under melt-spinning conditions" means that the poly (alkylene ether) does not decompose or volatilize during the spinning process.

“Microscopic” here means a particle size of about 0.05 to 2 or more microns Understood diameter. The length of the polyether particles, or "fibrils", is Va- to 10-fold of the thread diameter estimated. These particles are almost always visible in a light microscope. It can be assumed that these fibrils are connected to one another in some way, so that electrical Charges to earth are diverted.

In the following examples, parts and percentages are by weight, if nothing other is indicated.

" Example 1

Polyethylene terephthalate is prepared in the usual way by adding dimethyl terephthalate with Ethylene glycol converts with evolution of methanol. When the evolution of methanol stops

ίο, the reaction product is converted into a Autoclave and starts evacuating, glycol is developed when the high molecular weight condensation

_ sat is formed. Approximately in the middle of the condensation process, a nonylphenyl-capped poly- ether alcohol added in a glycol slurry. The condensation continues until a polyester of spinnable molecular weight. After the end of the polycondensation, the polycondensate becomes as a ribbon, squirted out, flaked

ao cut and then using a screw melt press spun into threads. The thread bundle is stretched and in a satin with weft woven flor. Samples of the test yarn and an unmodified control sample A are used five times Washed treatment followed by hand ironing for synthetic fabrics usual fixing temperature. After washing and ironing 5 times, each sample is subjectively to their static behavior against, the unmodified Polyester control sample A at 25% relative humidity

'tive moisture rated. The rating scale is enough from 1 (strong static) to 5 (no static). Cotton that is acceptable has a value from 3 to 4.

Table I.

By Conc valuation try cut tration of the static as proof Molecular-. Behavior after of the technical weight a 5-time. Progress Vo Washing ironing none __ Treatment. A (comparison) 4,600 6th 1 = 0 B. 4.6

Examination of the threads of sample B in the light microscope shows no visible streaking, but _B does. _B at higher magnification in an electron microscope, tiny stripes can be seen.

Example 2

There will be (a) 6% of a polyether compound of molecular weight 20,000 with hydroxyl end groups and (b) 6% of a polyether compound of molecular weight 20,000 terminated with methoxy groups in polyethylene terephthalate incorporated, which is spun as described above and ge-So in satin with weft pile is weaving. Samples of these products are labeled A υ and B, respectively.

The technical progress

^ The evaluation of the static behavior of this Samples after washing and ironing 5 times and an unmodified control sample C is given in tables. Samples of the tissue are made dyed with a disperse dye and 40 hours

exposed in a Xenotester to determine the lightfastness. It is found that the control sample C no fading, with the methoxy-capped polyether product (sample B) a very small change in hue and, for sample A, a serious change in Coloring is done. Strands from these yarns are boiled in dilute caustic soda, it becomes the Weight loss of these samples compared with the weight loss of control sample C.

Table Π

A. sample
B. C.
(Control sample; 20,000
6th 20,000
6th no 4.2
strength
change
880 4.3
low
change
100 1.0
no
change
100

Polyether compound

Molecular weight

Amount added,%

Evaluation of the static behavior after a

5 times washing and ironing process

Lightfastness of the disperse dye

Alkali sensitivity,% of control sample

It is seen that Sample B shows alkali sensitivity (amount of weight loss) which corresponds to that of the control sample, while the as The amount of weight loss for Sample A is almost nine times as fast.

Claims (1)

Claim: Process for the manufacture of filaments from linear polyesters in which at least 75% of the repeating units of the polyester chain at least one divalent carbocyclic Contain ring with at least 6th carbon atoms as an integral part of the polyester chain, wherein between the two binding sites of the ring to the polyester chain at least 4 ring carbon atoms, thereby characterized in that one melts the polyester, which is also a polymer Alkylene ethers with a molecular weight of at least 1300 in amounts of 3 to 15 percent by weight contains evenly as a separate phase, spun. Considered publications:
German publication No. 1000 778. 609 709/304 10.66 © Bundesdruckerei Berlin