DE2257926A1 - Polyester fibres with improved adhesion to rubber - made by applying an aq. epoxy cpd., pre-stretching in hot water, drying and stretching - Google Patents

Abstract

Fibres of linear polyesters with intrinsic viscosity over 0.65 are impregnated with 0.1-1.5 wt.% epoxy cpd. from an aq. compsn., pre-stretched in a water-bath at 65-85 degrees C, and after removing the adhering water, stretched substantially at over 200 degrees C. The epoxy cpd. is pref. an aliphatic or aromatic glycidyl ether with mol. wt. below 500 and epoxy equiv. wt. up to 250. It is pref. applied in amount of at least 0.6%, together with an amine hardener in amount of 5-50 wt.% of the epoxy cpd. Pre-stretching is pref. at 70-80 degrees C under tension of 0.15-0.60 p/dtex for 1.5-8 secs. and the subsequent stretching is at 230-240 degrees C. Strong fibres with good bonding properties are obtained with low amounts of bonding agent, which allow them to be processed like untreated fibres.

Description

Improvement of the Adhesion of Polyester Threads to Rubber The present invention relates to a method for improving the adhesive strength of polyester threads Rubber and other elastomers by impregnating the polyester spinning threads with an adhesion promoter based on epoxy compounds and a subsequent one two-stage stretching.

For textile inlays in rubber, especially tire cord, are in the last Increasingly, threads made from synthetic high polymers, including high molecular weight linear polyesters.

These threads have the advantage that their textile values largely match Requirements of the processing industries can be adapted to the above all, high strength of the threads and low elongation are required. Also will these threads have a high binding capacity with respect to rubber and other elastomers required, since most articles that receive such threads as reinforcement, are constantly exposed to high dynamic loads. If the adhesive strength is insufficient there is a loosening of the bond between the elastomer and the thread material over time, the destruction of the textile reinforcement by rubbing or local overheating caused by melting. For the manufacture of reinforced with textile insert Objects made of elastic polymer for motor vehicle tires, V-belts, Conveyor belts and the like, it is therefore of crucial importance that a high-strength insert material is available that works very well with the elastomer adheres.

To ensure adequate adhesion to rubber and other elastomers To achieve polyester threads, it is different from threads made of polyamides or Rayon needed to fill the threads with chemically reactive substances such as isocyanates, oxirane compounds or ethylene imine derivatives, to treat.

There are already numerous methods of improving liability of polyester threads on rubber have been described. In a number of these procedures the adhesion promoter is applied after the thread has been completed or fabric in one or more work steps mostly at a supplier or in the rubber industry. The other methods use one that improves the adhesion Pre-preparation already applied during the production of the polyester thread.

For economic reasons, the procedures are of the second group preferable to the former. The equipment supplier or the rubber industry can be involved in In this case, proceed with the polyester threads in the same way as with the threads from Polyamides or rayon.

Polyester threads pretreated in this way result either after treatment with an aqueous dispersion of resorcinol-formaldehyde precondensate and vinyl pyri dinlatex has a sufficiently high level of adhesion without the additional use of adhesion promoters on rubber or, if this latex treatment is omitted, on self-adhesive ¢ rubber compounds, which contain additives of resorcinol, formaldehyde donors and silica.

In the case of active adhesive equipment in one operation with production of the threads in a conveyor belt mainly find polyepoxides, possibly in combination use with anionic hardeners.

Such processes are described, for example, in DT-AS 1 .199 224 and DT-AS 1 212 245. According to this, the polyester threads are in a first stage treated with a diglycidyl ether and an amine as hardeners and then on 100 to 2450c heated, allowing a slight shrinkage. The bonding agent Glycidyl ether can be used either after drawing or at the same time as the spin finish be applied before stretching '. In a second stage there is a treatment with an aqueous dispersion of resorcinol formaldehyde precondensate and vinyl pyridine latex carried out.

Similar processes for the production of polyester cord are already in place described. From DT-OS 1 444 139 it is known, for example, the glycidyl ether Alcohols' with at least three OH groups, of which at least two to GlycidylSthergru} n are reacted, together with an amine optionally either on the undrawn Threads, the drawn threads, the cord ground yarn, the finished cord or fabric to apply. The processing condition of the polyester threads is good for achieving i Oil strength is obviously not characteristic of the claimed processes.

The impregnated threads undergo a heat treatment at 160 to -245 C exposed. The polyester threads are always drawn in one step Stretching pan at 220 ° C up to a stretching ratio of 1: 6.0.

In another embodiment of this method, the glycidyl ether an alcohol with more than two hydroxyl groups, at least two of which are glycidyl ether groups are implemented, together with an aliphatic or heterocyclic amine in the Spin finishes are used (-DT-AS 1 444 140).

As can be seen from DT-OS 2 056 707, pages 2 and 3, the use of epoxy compounds together with hardening agents can only be used in stretching processes, in which the thread does not overheat in the course of stretching or shrinking Metal surfaces such as heated pins, plates, godets or rollers are guided, because after a short time there will be deposits of the more or less hardened epoxy resin form, which hinder the further course of stretching, if not make it impossible.

The methods known from DT-OS 2 056 707 are therefore Epoxy compounds without hardener in the course of a spinning process on undrawn or incompletely drawn polyester threads are applied. It is here expressly pointed out to the problem with which the manufacturer of the liability must deal with improved polyester cord. The publication teaches that serving as adhesion promoters epoxy compounds as possible on the undrawn Thread should be applied, as only then will the necessary adhesive strength be obtained will. Otherwise the adhesive strength becomes essential worsened. On the other hand, as Example 3 shows, the sleep mediator is necessary in relative terms to be applied in high concentration if the adhesive strength is to be sufficiently high. As a result, there are high amounts of the epoxy compound on the thread, i.

a generally viscous, sticky substance. Because the adhesion promoter is preferably left on the threads, arises during further processing These threads, for example, when twisting, warping, shearing and weaving on the non-steering organs and thread brakes a sticky abrasion that has to be removed again and again. this However, it is practically impossible to carry out, so that after a short time high thread tensions which, in the harmless case, lead to uneven goods, but which also Can cause thread breaks.

The conveyor belt processes described at the beginning also bring problems which so far could not be solved in a satisfactory manner. If the adhesion promoter, as recommended, applied sometime before stretching, you get one fluffy goods with insufficient strength values. With the alternative option however, treating the threads with the adhesion promoter only after they have shrunk instead, the rubber adhesion is significantly worse.

The object of the present invention was to provide a method to develop; in which the identified difficulties of the previously known methods can be avoided, and this leads to polyester threads that have good adhesive strengths Rubber and other elastomers have and are also improved by Characterize textile technological properties.

The solution to this problem was surprisingly achieved by using a other stretching process. The one from the prior art for the production of high strength Polyester threads known stretching at temperatures above 2000C, as e.g. in the DT-AS 1 199 224 and 1 212 245 is described and for the achievement high strength values are considered indispensable, a stretching stage has been successfully implemented upstream, which is carried out in a water bath. Against all expectations becomes the adhesion promoter with which the threads are stretched in a water bath are impregnated, not completely washed out in this way of working. It has rather it is shown that before this stretching on the threads applied Epoxies under these working conditions into the non-oriented polyester threads diffuse in. Only the surface is washed off in the aqueous drawing bath attached excess; an effect) that turned out to be very beneficial since in this way the undesired abrasion is avoided. The new one led procedural step the stretching in the water bath thus fulfills a double function, namely one particularly gentle initial stretching and at the same time washing off the excess Adhesion promoter.

The stretching of polyester threads in aqueous baths is hitherto especially when processing very strong polyester cables like them are present in the manufacture of staple fibers.

With this method of operation, an even warming up should be achieved as quickly as possible of the cable to the stretching temperature.

Therefore, the cable is often heated to a certain temperature in a first bath preheated from e.g. 80 to 1000C and then in a second bath at the same temperature stretched up to six times the original length (DT-OS 1 660 471 and DT-OS 1 660 472).

Two-stage stretching in aqueous baths is also known per se. A method for producing a polyester-cotton type is described in which the tow in a bath at a temperature of 10 to 500C in proportion 1: 2.6 to 1: 3.0 is pre-stretched, where appropriate beforehand at the same Temperature can be preheated, and then in another water bath at 70 to 100 ° C or dry at 70 to 200 ° C up to a total draw ratio of 1 : 3.5 to 1: 4.0 is post-stretched (DT-OS 2 058 272).

With this method, polyester fibers can be obtained, their Strength is sufficient for processing into staple fibers, but it is sufficient for the Production of high-strength threads would be inadequate.

In order to behave high-strength polyester threads, what was known per se had to be Process of water drawing changed in a suitable manner and with for the production high-strength polyester threads known per se process steps for the present new manufacturing process.

The subject of the invention is thus a method of production high-strength threads made of high-molecular linear polyesters with good rubber adhesion by spinning a polyester raw material with; an intrinsic viscosity higher as o65, impregnation of the threads with an i-iaft mediator based on epoxy compounds and a subsequent two-stage drawing in which the threads are in front stretching with an aqueous preparation of a water-soluble, emulsifiable one or dispersible aliphatic or aromatic epoxy compound in one Application amount of more than about 0.15%, based on the weight of the dry threads, impregnated, these threads are then pre-stretched in a water bath at around 65 to 85 ° C and after extensive removal of the adhering water at temperatures above approx 200 ° C, generally at 220 to 2600C, preferably at 230 to 2400C, if possible largely post-stretched.

The pre-stretching of the treated with the glycidyl ether as an adhesion promoter Threads is done immediately afterwards in a water bath raised to a temperature of from about 65 to 8500, preferably from 70 to 80 ° C. This pre-stretching generally takes place with a tension of about 0.15 p / dtex to about 0.6o p / dtex, preferably from 0.20 p / dtex to 0.50 p / dtex, based on the final titre after second stretching. The residence time in the aqueous drawing bath is about 1.5 to 8.0 seconds, preferably 2.0 to 4.0 seconds. That the threads from the pre-drawing Adhering water is largely, suitably up to about 8 to 15% by weight e.g. removed by stripping or squeezing off before the threads are re-drawn be forwarded.

The applicable pre- and total hiding ratio depends on the Preorientation of the spun threads, among other things, this depends on the intrinsic viscosity of the thread, the take-off speed during spinning, the reheating of the freshly spun Thread immediately under the nozzle. So so the overall drawing ratio is so higher, the lower the pre-orientation. The one to be selected for pre-stretching in water The pre-stretching ratio results in accordance with the stretching stresses listed above depending on the pre-orientation between 1: 1.1 and 1: 3.5. In principle is it even possible not to stretch at all in the water bath and the water bath only to be used to wash off the adhesion promoter that has not diffused in.

However, since the pads have a tension of only 0.05 to 0.1 Having p / tex and thus running through the water almost without tension is the technical one Feasibility in this way of working is difficult.

Suitable as a raw material for carrying out the claimed process all high-melting thread-forming polyesters, especially those which consist predominantly, i.e. at least 80%, of ethylene terephthalate units. The remaining dicarboxylic acid and diol components of these (co) polyesters can be used common co-components in the production of stretched polyester structures, such as Isophthalic acid, p, p'-diphenyldicarboxylic acid, all possible naphthalenedicarboxylic acids, Hexahydroterephthalic acid, adipic acid, sebacic acid and glycols such as trimethylene, Tetramethylene, hexamethylene and decamethylene glycol, etc.

A very preferred polyester is polyethylene terephthalate.

According to the invention, the polyester raw materials used should be high Viscosity, have at least an intrinsic viscosity greater than 0.65. the The desired high viscosity values can be achieved with the aid of known processes such as condensation in the melt, an additional post-condensation in the melt with or without a condensation accelerator or post-condensation in solid state.

In addition, it is advantageous if the raw material used as a raw material high molecular weight polyester is characterized by a low content of free carboxyl end groups which, as is well known, increased them. Resilience to the Exposure to moisture, high temperatures, hydrolysis and damage caused by Rubber as well as the chemicals used in its incorporation into rubber.

At the preferred viscosities, the low carboxyl end group content in a known manner by solid condensation or by end group closure with monofunctional epoxides, isocyanates, Diazomethane and others can be achieved in the melt or in the residual state.

The spinning process is to be carried out in such a way that the described and for a successful implementation of the manufacturing process before beneficial raw material properties as far as possible in the software.

The drawing process can be carried out with thread sizes from 250 to 5500 Perform dtex final titer. So stronger threads can be used than it is possible according to the previously known methods, at least for threads with protective twist has been. The threads can be fed to the stretching process in the untwisted state However, it has proven to be more beneficial for the post-stretching process to use them to be provided with a light protective twist.

The adhesion promoters are all aqueous solutions, emulsions or dispersions used, in which the adhesion-promoting substance in a concentration of about 2 to 30, preferably 3 to 20 wt. S is contained, and before the stretching so applied that not on the thread about 0.15 to about 1.5 wt .-%, preferably 0.3 to 1.0 wt .-% are. If necessary, hardeners can be added to these preparations are added, the amount of which is 5 to 50 wt. Of the adhesion promoter used can.

The substances known in the prior art are suitable as adhesion-promoting substances the technology already listed epoxy compounds, as they are detailed, for example in U.S. Patent 2,829,071 and DT-OS 2,056,707, namely aliphatic, aromatic, cycloaliphatic and heterocyclic saturated and unsaturated polyester-polyepoxides and polyether-polyepoxides, which by halogen atoms, Hydroxyyl groups, alkoxyl groups and the like may be substituted as far as These compounds are used to produce aqueous preparations in the concentrations given above can be produced.

The epoxy compounds should expediently have a molecular weight of less than 500 and an epoxy equivalent weight of up to about 250. The higher molecular ones Epoxy compounds are insoluble in water and are difficult to emulsify.

The polyether epoxides are particularly suitable for the process of the invention, as they do by reacting an excess of epichlorohydrin or dichlorohydrin with polyvalent aliphatic or aromatic hydroxyl compounds such as glycerine, Ethylene glycol, diethylene glycol, butanediol, sorbitol, male, pentaerythritol, polyvinyl alcohol, Trimethylo.lpropane, resorcinol, catechol or hydrate quinone can be obtained. One preferred Adhesion promoters that are used include the reaction product of glycerine. Epichlorohydrin, The inventive method can be with and without the addition of a Carry out hardening agent for the epoxy compounds - If used alone of epoxy compounds, these are generally used as aqueous preparations in Concentrations of about 10 to 30% by weight, preferably 12 to 20% by weight, are used, an application amount of more than about 0.6 is expedient. %, preferably 0.8 to 1.2%, based on the weight of the dry threads, is adhered to. Using a curing agent, it is possible to reduce the amount of epoxy used. In this case, the concentration of the epoxy compounds in the aqueous Preparations usually about 2 to 10% by weight, preferably 3 to 8% by weight. In this In this case, an application amount of about 0.15 to about 1.0% is expedient, preferably 0.2 to 0.6%, based on the weight of the dry threads, complied with. Suitable Hardeners are aliphatic, aromatic, cycloaliphatic or heterocyclic Mono- and polyamines containing nitrogen as a heteroatom, such as those described in U.S. Patent 2,902,398, column 6. Preferred compounds used as hardeners are piperazine, hexamethylenediamine, polyethyleneimine, triethanolamine and dicyandiamide.

The production of the threads can, in principle, be carried out in the manner described below Be carried out in a manner (see illustration). The threads that are spun are either in the untreated state or after applying a protective twist of 30 to 60 tpm The drawing line shown in the figure is specified by the reel (1). To They are combined into a group of threads lying next to one another on the device (2) with an aqueous preparation of an epoxy compound, which is also an amine hardener can contain, evenly prepared. This can be done in a known manner either by tangential Touching the threads with a rotating preparation roller, by spraying on or be done in a different way. The threads are then fed to the inlet element (3). You can also proceed in the reverse order and the thread sheet first Feed in the inlet element (3) and then apply the adhesion promoter.

The threads are then placed in a water bath (4) in which they are pre-stretched. The water bath can either be designed so that the Threads are passed through deflection organs under water, or the threads are without Deflection stretched in the surge of a water surge bath. Then the thread sheet dehydrated with the aid of the device (5), which can be done e.g. by squeezing or by suction or blowing with hot air, and fed to the extraction device (6), which runs faster than the inlet element according to the selected predrawing ratio (3).

After the take-off device (6), the threads are passed through a hot zone (7) which can e.g. be a duct that heats with hot air or radiation or a heated metal surface. In doing so, they are between the discharge organs (6) and (8) brought to the desired overall draw ratio. To carry out the subsequent fixation is between the conveyor elements (8) and (10) a built-in heated zone (9) for which similar devices can be used, as for the heated zone (7), and the speed of the conveyor element (10) opposite the conveying element (8) is reduced according to the desired shrinkage. Possibly before winding (12) on the device (-11) a subsequent preparation with a a lubricant-containing preparation take place.

The threads obtained can be twisted, warped, be warped and woven. In order to ensure the corresponding higher liability between such To get twisted or woven fabrics with rubber, they have to be, as is the case with rayon and Polyamide Usual, in a known manner with an aqueous preparation of a resorcinol-formaldehyde precondensate and a vinylpyridine-styrene latex and then heated. Otherwise it is necessary to use so-called self-adhesive rubber compounds, e.g.

are described in French patent 1,483,340.

The advantage of the claimed method over the prior art lies primarily in the fact that threads of high breaking strength and very good adhesive strength to be obtained rubber, the Order to adhesion promoter on finished thread is very low. This is the properties of the thread surface practically identical to those of a thread without an intermediary and the threads are to handle without difficulties in the further processing stages.

Another advantage of the process is the very even heating of the thread in the first drawing stage in water, which results in a very even drawing and thus high degrees of stretching without occurrence of capillary breaks, even with strong ones Thread titers made possible.

In the following examples, unless expressly stated otherwise indicated, the parts are parts by weight and percentages are percentages by weight.

Example 1 Filaments of polyethylene terephthalate of intrinsic viscosity 0.72 spun with a take-off of 600 m / min from 200 individual capillaries and have a spinning denier of 6500 dtex, are turned up to 50 tpm and presented to the stretching device shown in the figure.

The water bath used has a length of 1 m and a temperature of 73 ° C, the stretching channel an air temperature of 235 ° C and the shrinking channel of 240 ° C. In front of the inlet element (3) an aqueous one is applied with the aid of the device (2) 15% preparation of a reaction product from one mole of glycerine and 3 moles of epi- ' chlorohydrin (epoxide equivalent 161), its production in Houben-Weyl, methods of organic chemistry, Volume XIV / 2, page 543, is described on the threads A galette is applied so that it sits on the thread before immersion in the water bath 0.9% epoxy compound. The threads run over the inlet organ (3), the passes it on to the subsequent water bath at a speed of 15 mXmin. After the water bath, the adhering water is applied to the squeezing device (5) to removed to 12%. The threads are taken up by the take-off device (6), whose Rollers move at a peripheral speed of 33 m / min. Between Inlet element (3) and the squeezing device (5) they have a voltage of 450 p / thread, erit speaking 0.41 p / dtex, based on a final denier of 1100 dtex.

After squeezing, the threads have 0.55% of the above listed agent. Between the discharge elements (6) and (8) takes place second stretching in the hot air duct at 235 ° C., in a ratio of 1: 2.8, with the Rolls of the take-off element (8) have a peripheral speed of 93 m / min. Between the conveying elements (8) and (10) there is a shrinkage of 3.5% in the channel (9) approved, aftertreated in the device (11) with a preparation containing paraffin oil and finally wound with the winding head (12).

The threads obtained can be easily processed on a double twisting machine, as described e.g. in Koch-Satlov, Großes Textil-Lexikon, page 282, Process into a thread of construction 1100f200 Z 360 x 3 S 360. This thread will in a known manner with an aqueous dispersion based on resorcinol-formaldehyde precondensate and Viny 3pyridin-Styrene-Butandiene-Latex (RFL) treated, heated to 220 ° C, and vulcanized into a Karlcass mixture 1 of the following composition: 100 Parts smoked sheets 40 "SRF-soot 4" spruce tar 1 lt phenyl-ß-naphthylamine 5 " Zinc Oxide, Active 0.8 "N-Cyclohexyl-2-benzthiazole-sulfenamide 2.5" Sulfur One Another sample of the said thread is put into a Rubber mixture 2 vulcanized in with the following composition: 100 parts smoked Sheets 30 SRF carbon black 15 "precipitated silica 2.5 t resorcinol 5 lt zinc oxide, active 2 "stearic acid 1 lt" phenyl-ß-naphthylamine 1.8 "hexamethylene tetramide 1" N-cyclohexyl-2-benzthiazole sulfenamide 2.5 "sulfur When testing the bond strength with the one listed below If the mode of operation is measured, good values are obtained for both rubber compounds.

In addition, the non-latexed threads have some analytical functions Determinations made, the results of which are summarized with the adhesion values in the table are. These determinations are made according to the following methods.

The determination of the content of adhesion promoter takes place with the help of Chlorine determination according to Wickbold by burning the thread, potentiometric determination the chlorine content and calculation of the originally present amount of epoxy from your Chlorine content, which for the present product is 11.8%.

The extractable preparation order is determined by two-way extraction of the threads with methanol in a Soxhlet and weighing of the dried Extract.

To determine the abrasion, the prepared thread is driven at a speed pulled through a grid at 50 m / min, so that it is alternately above and below the grid wires.

The grid used consists of 11 steel wires of the diameter 0.1 mm, which are attached at a distance of 1 mm. The amount of rubbed off Dissection is done by weighing the grid before and after passing the sutures determined.

To determine the rubber adhesion, the force that is required is measured is to pull the thread to be tested out of the test item. The length of the The thread in the test specimen is exactly 10 mm.

Example 1 a (blind test for Example 1) polyethylene terephthalate threads are produced according to Example 1, but using the preparation device (2) no adhesion promoter applied.

As can be seen from the table, the methanol extract for this is Thread 0.85%, the abrasion 0.19 mg / 250m. The comparison shows that in the way of working according to the method according to the invention, as described in Example 1, only one minimally higher abrasion is obtained than in the blind test 1 a without adhesion promoter.

Example 2 (comparison with example 1) This comparative example shows that difficulties in further processing arise when large quantities of the adhesion promoter remain on the threads.

A polyethylene terephthalate raw material with an intrinsic viscosity of 0.72 is made in a known manner by a continuous spinning draw process like it for example, in U.S. Patent 3,216,187, filaments of denier 1100f200 processed and the spin finish 10% of that described in Example 1 n ;; ago Epoxy compound added.

The thread resulting from this method of operation is made on a double twist machine turned up to 360 tpm with Z-twist.

It starts to work on the thread brake after a short running time to deposit a sticky, rubbery coating that first becomes a thread with a increasing number of loops, until finally the friction in the thread brake becomes so large that the thread breaks. Proper processing of the thread is impossible because of its high epoxy content. The results of the analytical determinations can be seen from the table.

Example 2a (blank test for example 2) The procedure is analogous to example 2 worked, but no adhesion promoter applied.

The comparison of this blind test with Example 2 shows that the high abrasion, which is measured for Example 2, does not apply to this procedure removed adhesion promoter.

Example 3 The .Polyäthylenterephthalatfäden are according to Example 1 produced, but on the device (2) instead of the 15% preparation of the Only 6% epoxy compound used, the 0.6% piperazine hydrate as a hardener is admitted. About the effect of the water bath on the content of epoxy compounds to demonstrate, the Apply before immersion in the bath determined and measured 0.42%, while on the finished thread only 0.23 % are detectable.

As the inert ones in the table show, the threads obtained can Process flawlessly, show little abrasion, and it will be suitable for both the latexed Twine in thread mix 1 as well as for the raw thread in thread line 2 good tensile strengths obtain.

Example 4 The polyethylene terephthalate threads are essentially manufactured as described in Example 1, but on the device (2) instead of the reaction product of glycerol and epichlorohydrin, an 8% aqueous solution Preparation of 1,3-butanediol diglycidyl ether with the addition of 0.8% hexamethylenediamine applied to the threads.

The resulting threads can be turned on the double twisting machine Process flawlessly, resulted in only little abrasion and have rubber compounds on both good adhesive strength.

Example 5 Polyethylene terephthalate threads of the 6500f200 spinning machine are made spun analogously to Example 1 and twisted three of these threads together to form a thread with 30 tpm. This thread is presented to the drawing system sketched in the figure, in the device (2) with an aqueous 7.5% preparation of that described in Example 1 Reaction product of glycein and epichlorohydrin with the addition of 1.0% piperazine hydrate prepared and in one Water bath at 1 m length and one temperature of 76 ° C. at an infeed speed of 20 mm in a ratio of 1: 1.6. Then in the channel (7) at 2400C in a ratio of 1: 3.7 and then between the conveying organs (8) and (10) in the channel (9), the temperature of which is 2110 ° S has shrunk by 3.8 F.

Threads with a titre of 3240f600 are obtained, from which a thread of the construction 3240f600 Z 160 x 2 S 160 is produced, which according to Example 1 Equipped with an RFL latex and in rubber compound 1, as well as without RFL equipment is vulcanized into mixture 2. Both cases will be good Adhesion strength measured.

Example 6 (comparative example) A polyethylene terephthalate thread of the Titers 6000f200 is treated with the following preparation when spinning: 96Q parts Water 100 parts butyl stearate 100 parts to addition compound of 20 moles of ethylene oxide to 1 mole of sorbitol monolaurate 100 parts 1,3-butanediol diglycidyl ether 10 parts piperazine hydrate (6H2 0) The result is an application of 0.7% to 1,3-butanediol diglycidyl ether and a methanol extract of 2.2% on the spun thread It is not possible to do this Threads, as described in DT-AS 1 212 245, at 2250C in a ratio of 1: 6.0 stretch.

They are therefore only stretched 5.5 times at the same temperature and at 245 0C under a tension of approx. 300 thread shrunk. The resulting The thread is very fluffy and breaks even with this reduced stretching ratio several times off.

A further processing of the thread on the twisting machine is not possible T a b e l le Example 1 1a 2 2a 3 4 5 6 Adhesion promoter content % 0.42 0.0 0.95 0.0 0.23 not 0.31 0.70 determined methanol extract% 0.92 0.85 1.42 0.84 0.87 not 0.97 2.20 determined abrasion mg / 250 m 0.27 0.19 1.18 0.34 0.31 0.18 0.24 -workability 1100f200 not bad - good good 3240f600 not on the Twisted 2360-3S360 determined break Z160-2S160 processing machine good good bar rubber adhesion in 17.2 - 17.9 - 18.1 15.8 23.4 - mixture 1 kg / cm - rubber adhesion in 16.7 - 16.5 - 17.7 14.4 22.2 - mixture 1 kg / cm -

Claims (8)

Claims 1. A method for producing high-strength threads high molecular weight linear polyesters with good rubber adhesion by spinning a Polyes: ter raw material with an intrinsic viscosity higher than 0.65, impregnation the threads with an adhesion promoter based on epoxy compound and then Drawing, characterized in that the threads are applied before drawing an aqueous preparation of an epoxy compound in an amount of about 0.1 to 1.5%, based on the weight of the dry thread, applies these threads afterwards pre-stretched in a water bath at temperatures of about 65 to 85 ° C and after extensive removal of the adhering water at a temperature above 200'0C as far as possible post-stretched. 2. The method according to claim 1, characterized in that on the undrawn Threads an aqueous solution, emulsion or dispersion of an aliphatic or aromatic Glycid ethers with a molecular weight below 500 and an epoxide equivalent weight up to 250. 3. Method according to claim 1 or 2, characterized in that the epoxy compounds in an amount of at least 6%, based on weight of the dry threads. 4. Process according to Claims 1 to 3, characterized in that an aqueous preparation containing about 2 to 30 wt .-% of epoxy compounds applied will. 5. The method according to claims 1 to 4, characterized in that together with the epoxy compound a curing agent, especially an aliphatic one or heterocyclic mono- or polyamine, in an amount of about 5 to 50% by weight the epoxy compounds used are applied to the threads. - 6. Procedure according to claims 1 to 5, characterized in that the pre-stretching in "a" water bath takes place at temperatures of 70 to 800C. 7. The method according to claims 1 to 6, characterized in that the pre-stretching takes place under a stretching tension of 0.15 to 0.60 p / dtex. 8. Process according to Claims 1 to 7, characterized in that the dwell time of the threads in the water bath is about 1.5 to 8.0 seconds. 9, method according to claims 1 to 8, characterized in that the post-stretching is carried out at temperatures of 230 to 240.degree.