EP0746648A1 - Process for dyeing polytrimethylene terephthalate fibres and use of thus dyed fibres - Google Patents

Abstract

PCT No. PCT/EP95/00455 Sec. 371 Date Dec. 12, 1996 Sec. 102(e) Date Dec. 12, 1996 PCT Filed Feb. 9, 1995 PCT Pub. No. WO95/22650 PCT Pub. Date Aug. 24, 1995The present invention relates to a process for coloring polytrimethylene terephthalate fibers by treating the fibers with an aqueous liquor containing at least one dispersing colorant, in the absence of a carrier and the application of pressure. The temperature of the treatment is carried out at or below the boiling point of the liquid, within 20 DEG C. of the boiling point of the liquor. The coloring process begins at a liquor temperature between 20 DEG and 50 DEG C., and the temperature is raised over a period of 20 to 90 minutes. The liquor is then cooled to a temperature between 20 DEG and 50 DEG C., preferably at a rate of cooling of 1 DEG C. per minute, so that at least 95% wt. % of the colorant is absorbed by the fibers, and the dispersing colorant penetrates the fibers to a relative depth of at least 5% with respect to the diameter of the fibers.

Description

 Process for dyeing fibers of the

Polytrimethylene terephthalate and the use of colored fibers obtainable by this process

description

The invention relates to a process for dyeing fibers of polytrimethylene terephthalate with disperse dyes in an aqueous liquor at or below the boiling temperature of the liquor and the use of the fibers dyed according to the invention.

Polytrimethylene terephthalate (PTMT) is a polyester that has 1,3-propanediol as the diol component and terephthalic acid as the dicarboxylic acid component. Large-scale polyester syntheses can basically be carried out according to two different processes (H.-D. Schumann in Chemiefaser / Textilind. 40/92 (1990), p. 1058ff).

On the one hand, the older process, which was used exclusively until about 1960, via the transesterification of methyl ethyl terephthalate with a diol to the bishydroxyalkyl terephthalate and the subsequent one

Polycondensation of the same. On the other hand, the process of direct esterification of terephthalic acid with a diol, which is mainly used today, and the subsequent polycondensation.

In the transesterification, dimethyl terephthalate is mixed with 1,3-

Transesterified with the addition of catalysts at temperatures of 160-210 ° C and the methanol released was distilled off from the reaction mixture at normal pressure. The reaction mixture, which consists predominantly of bis (3-hydroxypropyl) terephthalate, is further heated to 250-280 ° C. under reduced pressure and the 1,3-propanediol released is removed. The formation of the polytrimethylene terephthalate Bis (3-hydroxypropyl) terephthalate can be catalyzed by the same catalyst as in the transesterification, or another polycondensation catalyst is added after the same has been deactivated.

Reaction scheme

-HO-CH, -CH, -CH, -OH

The preparation of polytrimethylene terephthalate is already described in GB 578079. The transesterification of dimethyl terephthalate with 1,3-propanediol is catalyzed with sodium and magnesium. The alcohols released are distilled off at atmospheric pressure and the reaction mixture is heated further in vacuo until polymeric polytrimethylene terephthalate is obtained.

A composite fiber made of polyethylene terephthalate and polytrimethylene terephthalate is described in GB 1075689 Bei The representation of the polytrimethylene terephthalate is based on dimethyl terephthalate and 1,3-propanediol and titanium tetrabutylate is used as the transesterification and polycondensation catalyst.

From FR 2038039 two catalyst systems for the preparation of polytrimethylene terephthalate are known. Both times it is assumed that dimethyl terephthalate and 1, 3-propanediol. On the one hand, NaH [Ti (OBu) 5] is used as the transesterification and polycondensation catalyst and in the other process "Tyzor TBT" from Du Pont and MgCÜ3 are used as transesterification catalysts and an antimony compound as the polycondensation catalyst.

German Offenlegungsschrift 19 54 527 on catalysts for the production of polyesters describes another possibility for catalysis in the production of

Polytrimethylene terephthalate described. Here too, dimethyl terephthalate and 1,3-propanediol are assumed.

Manganese (II) acetate tetrahydrate is used as the transesterification catalyst and hexagonal crystalline germanium dioxide with a

Particle size less than 2 μm use. These catalysts can also be used to prepare dipolymers from terephthalic acid, 1,2-ethanediol and 1,3-propanediol.

Another non-titanium based catalyst mixture is described in U.S. Patent 4,167,541. Here cobalt acetate and zinc acetate are described as catalysts for the transesterification of dimethyl terephthalate with 1,3-propanediol and antimony oxide is used as the catalyst for the ^' polycondensation.

In U.S. Patent 4,611,049 and German

Publication DE 34 22 733 is a new one

Catalytic system described. Again starting from Dimethyl terephthalate and 1,3-propanediol are added as titanium tetrabutylate as a catalyst. In addition, p-toluenesulfonic acid is added as a promoter so that a higher molecular weight is achieved.

In 1988 CC Gonzalez, JM Perena and A. Bello (J. Polym. Sei., Part B: Polymer Physics 26 (1988), 1397) are linear polyesters starting from dimethyl terephthalate, 1, 3-propanediol and ditrimethylene glycol. As transesterification and Polycondensation catalyst is used tetraisopropyl titanate. Copolymers of terephthalic acid, 1, 3-propanediol and ditrimethylene glycol can also be prepared using the same catalyst.

Only recently have various other catalyst systems been described in EP 547 553. Starting from dimethyl terephthalate and 1,3-propanediol, titanium tetrabutylate, sodium and titanium tetrabutylate, zinc acetate, cobalt acetate and titanium tetrabutylate as well as butylhydroxytin oxide are described as transesterification catalysts. Titanium tetrabutylate, antimony trioxide, butylhydroxytin oxide and the combination of antimony trioxide and butylhydroxytin oxide are used as polycondensation catalysts.

For the first time, a synthetic route for direct esterification is also given here. Starting from terephthalic acid and 1,3-propanediol, the esterification is carried out thermally under pressure and the subsequent polycondensation is catalyzed by antimony trioxide.

All of the publications listed showed different ways of making PTMT or fibers from it. However, none of the publications gave a technical lesson regarding the dyeing of the PTMT fibers.

With regard to other polyester fibers, e.g. B. polyethylene terephthalate fibers, there is already a whole series of investigations regarding the dyeing Behavioral. It is known (Herlinger, Gutmann and Jiang in CTI, chemical fibers / textile industry. 37 J89 _. , February 1987, pp. 144-150) that the use of polyethylene terephthalate in textile technology was always associated with certain problems with regard to dyeings.

Basically, polyester can only be used with carriers or under so-called HT conditions - i.e. H. at elevated temperature, e.g. B. 130 ° C in pressure vessels - optimally stain with disperse dyes (Bela v. Falkai in "Synthesefaser", Verlag Chemie, Weinheim, 1981, p. 176). Carriers are special aids that have to be added to the dye liquors in order to enable dye absorption in practice. Examples of carriers that can also be referred to as fiber swelling agents include a. o-hydroxybiphenyl or

Trichlorobenzene. It is believed that such auxiliaries lower the glass transition temperature above which larger molecular segments of the fibers become mobile in the non-crystalline regions, which accelerates the dyeing process.

The need to remove carriers from the fiber after dyeing in order to avoid an unfavorable influence on the performance properties of the fibers, environmental reasons (pollution of waste water and air by carriers) and problems with dyeing

Polyester-wool blends (wool cannot be dyed using the HT process) led to the development of carrier-free dyeable polyester fibers at cooking temperature.

In order to produce polyesters which can be dyed without pressure at cooking temperature without a carrier, it is known to

Modify polyester chemically or physically (Herlinger et al. In: Chemical fiber / textile industry CTI 37/89, pp. 144 - 150, in chemical fiber / textile industry CTI 37/89, pp. 806 - 814 and in chemical fiber / textile industry CTI 40/92 , February 1990). For the chemical modification, for example, ether modification was carried out _. rtes polyethylene terephthalate. Thus, during the production of polyethylene terephthalate polymer (PETP), polyether blocks consisting of polyethylene glycol (PEG) units were built into the PETP chains, which, because of their mobility, make it easier to pull up the dye. Attempts have also been made to polymerize polybutylene glycol units into polyethylene terephthalate instead of the PEG units. The glass transition temperature is also lower in these types of polyester and the dyeing behavior is significantly improved.

Furthermore, it is known to improve the coloring properties of copolyesters from polyethylene terephthalate and polybutylene terephthalate, which, however, do not have sufficient thermal stability, so that, like pure polybutylene terephthalate, which in principle can also be dyed without a carrier, it has such a low melting point that it does not allowed the high necessary in the finishing steps

Apply temperatures as alternatives are also out of the question.

In contrast, physically modified types of polyethylene terephthalate, which are produced by coextrusion of mechanical mixtures of

Polyethylene terephthalate and polybutylene terephthalate granules were produced.

From DE 36 43 752 AI it is known to dye fibers of the polybutylene terephthalate carrier-free and pressure-free with disperse dyes in an aqueous liquor.

From Ullmann, 4th edition, vol. 22, p. 678 (1983) it is known that sometimes very bright tones of colorations can be achieved with PET by dyeing without pressure without a carrier. Dispersion dyes that are already suitable for this purpose are Diffuse 100 ° C sufficiently quickly in PET fibers, e.g. BCI Disperse _. Red 60. However, as already mentioned above, this procedure results in very weak ring colorations on the fiber surface, whereby as a rule only an extremely small part of what is offered in the fleet

Dye is added. In any case, the result is light shades with low color intensity. This generally applies to all disperse dyes, including those that have a high diffusion coefficient.

Finally, one knows from US 3,841,831

Dyeing process for polyester fibers, in which carrier-free and pressure-free dyeing is carried out with dispersion dyes from an aqueous bath at 25 to 100 ° C. However, this general statement is severely restricted in the description of US 3,841,831, on the one hand on PET fibers, on the other hand to only extremely small amounts of dye in the dyebath, and in addition the dyeing process indicated always includes an additional fixing step in order to allow the dye to penetrate somewhat more deeply to allow in the fiber. All this further supports the fact that the use of PET in textile technology has so far not allowed carrier-free, pressure-free and optimal staining.

Basically, it should also be noted that most of the carrier products which have become known so far and which can be dyed free of pressure at cooking temperature hardly correspond to the idea which the consumer associates with the known polyester fibers; In some cases the initial modulus of elasticity is reduced (lobed grip), the tendency to creases increases, the wash resistance suffers, the ability to recover decreases or the susceptibility to pilling increases.

In view of the prior art set out, it was an object of the invention to provide a process for dyeing fibers of polytrimethylene terephthalate, which is a permanent dyeing which is gentle on the environment Permits polytrimethylene terephthalate fibers and also leads to dyed polyester fibers which both have excellent processing properties and also meet the demands placed on polyester fibers from a thermal and mechanical point of view.

In particular, the dyed fibers should always have an increased resistance to dyeing when using the fibers and textile products made therefrom where there can be increased abrasion on the fiber surface.

These and other tasks not specified are solved by a method having the features of the characterizing part of claim 1. Advantageous method modifications are protected in the claims dependent on claim 1.

The fact that polytrimethylene terephthalate fibers (PTMT fibers) are treated with an aqueous liquor having at least one disperse dye, the temperature being at or below the boiling temperature of the liquor, no carrier being present, the process is carried out without pressure, with the dyeing at a liquor temperature between 20 and 50 ° C is started, the temperature within 20 - 90 min, preferably within 45 min, brought to the boiling temperature of the liquor or to a dyeing temperature which is at most 20 ° C below the boiling temperature of the liquor, the dyeing at least

20 min at the dyeing or boiling temperature, preferred

30 - 90 min, and then cooled to a temperature of 20 - 50 ° C, preferably at a cooling rate of 1 ° C per min, so that at least

95% by weight of the dye offered in the liquor absorbs onto the PTMT fibers, and the disperse dye penetrates into the PTMT fibers at least at a relative depth of 5% based on the diameter of the fiber to be dyed it dyed PTMT fibers with excellent color properties as well as with excellent mechanical and thermal properties are available, which can be very advantageously processed into all kinds of woven, knitted or knitted fabrics.

Within the scope of the invention it has been found that in principle all known polytrimethylene terephthalate fibers can be dyed carrier-free with disperse dyes. In particular, this also includes the fibers obtainable according to the process disclosed in EP 0 547 533.

This was somewhat surprising since, based on the knowledge gained with regard to the

Polyethylene terephthalate were not readily available with the favorable coloring behavior of the

Polytrimethylene terephthalate was to be expected.

Even if one takes into account that it was known that polyesters made from pure polybutylene glycol terephthalate could be dyed carrier-free, this was not to be assumed from the outset for fibers made from polytrimethylene terephthalate. In addition to the coloring properties, u. a. also the thermal properties of the polyester for its usability to wear. In order for a polymer to be considered as a fiber raw material for textile purposes, the melting point of the underlying should

Esters are well above 200 ° C. However, the melting points of the esters from diols with odd-numbered methylene groups in the diol are generally below the melting points of the esters with the next higher even-numbered methylene groups in the diol. However, this effect can only be seen clearly with the higher methylene group numbers. In the case of polytrimethylene and polybutylene terephthalate, the melting points are almost identical. Also with regard to the glass transition temperature, which should be as low as possible for good coloring properties at cooking temperature without the addition of a carrier, the prior art did not provide any clear indication of its suitability for carrier-free staining for the polytrimethylene terephthalate. So there is very different information from different authors. G. Farrow et al. in Makromol. Chem. 38 (1960), p. 147 settle the glass transition temperature at 95 ° C above that of polybutylene terephthalate, while in US Pat. No. 3,681,188 for polytrimethylene terephthalate

Glass transition temperature of 45 ° C is specified. Jackson et al. in J. Appl. Polym. Be. 14 (1970), p.685 published a glass transition temperature for polytrimethylene terephthalate which was above that of polybutylene terephthalate. All in all, based on the available physical data regarding the coloring behavior, it was not possible to conclude from the outset that there was a relationship to polybutylene terephthalate or polyethylene terephthalate.

Polytrimethylene terephthalate fibers which are obtainable from polytrimethylene terephthalate, which are preferred using a single catalyst, are particularly preferably dyed in the invention

Titanium compounds, for the transesterification and the subsequent polycondensation. It is particularly advantageous here that the transesterification catalyst does not have to be converted into an ineffective form before the polycondensation. Furthermore, the catalytically effective one

In many cases, species are only generated in the reaction mixture and it can remain in the polymer at the end of the reaction.

For the invention, fibers can be made from the PTMT material obtained by all methods familiar to the person skilled in the art getting produced. This is preferred

Polytrimethylene terephthalate for fiber production is subjected to a melt spinning process, the polymer material preferably being dried beforehand at temperatures around 165 ° C. to water contents of less than 0.02% by weight. The polyester staple fibers obtained can optionally be hot-drawn before dyeing with a stretching system known to the person skilled in the art at temperatures of 110 ° C. (heating mandrel) and 90 ° C. (block heater).

Those which can be used in the process according to the invention

Disperse dyes are not limited to specific compounds, but rather include all dyes with low water solubility, which are able to dye hydrophobic fibers from an aqueous dispersion. The disperse dyestuffs in question are familiar to the person skilled in the art, examples being dyestuff classes of the azo series, amino or aminohydroxyanthraquinones or nitro dyes. In addition, there are monoazo dyes which have several nitro or cyano substituents, and heterocyclic azo and

Polymethine dyes. Representatives of these classes of dyes can be used alone or in a mixture of several, representatives of different classes also being able to be mixed with one another, for example to produce green or black shades. Also conceivable in the sense of the invention are dyestuffs for dyeing processes, such as are used in principle for dyeing cotton, in which a diaminoazo compound is dyed by the dispersion process, diazotized on the fiber and turned into black with a suitable coupling component

Trisazo body implements. The invention also includes all so-called coloring variants for disperse dyes.

At the beginning of the invention, the disperse dyes are present in an aqueous liquor. They spread out when staining between the aqueous liquor and the fiber treated with it, such as between two immiscible or limitedly miscible liquids, and finally, if the reaction is carried out appropriately and the substance is selected, are drawn onto the fiber.

The treatment of the fibers takes place in the invention

Process essentially by contacting fibers and liquor (in an aqueous solution containing the disperse dyes and any necessary auxiliaries), for example by immersing the fibers in the liquor and lingering in the liquor. This process plays essential to the invention without the addition of carriers and without pressure, i. H. without using pressures exceeding atmospheric pressure at the boiling point of the liquor or at a temperature below the boiling point of the liquor such that at least 95% by weight of the dye offered in the liquor absorbs onto the PTMT fibers. As a rule, this corresponds to a bathing coloring, i.e. H. the dye offered is completely accepted by the treated fibers within the detection limit.

In an expedient modification of the method according to the invention, the

Polytrimethylene terephthalate fibers used a liquor which has between 3.0 and 7.0 g of disperse dye per kg of PTMT fiber to be dyed. In a particularly advantageous embodiment of the process, the liquor used contains between 4.5 and 5.5 g of disperse dye per kg of PTMT fiber. The disperse dye amounts mentioned relate in each case to the pure dye contained in the commercial dye.

As is known, commercial dyes can contain large amounts of auxiliaries (up to 80% by weight).

As already stated, dyeing is carried out according to the invention without a carrier without pressure at the boiling temperature of the aqueous liquor or at temperatures below it. Depending on The composition of the aqueous liquor, in particular the content of dye or dyeing aids (no carriers), the boiling point of the liquor can also be above 100.degree. However, it is clearly established that, even at boiling temperatures of over 100 ° C., the dyeing is carried out according to the invention without pressure, ie without using a special pressure vessel, however, for example in a closed dyeing cup. However, the boiling temperature of a dyeing liquor is generally changed only slightly by the addition of dye and / or auxiliary agents. In an advantageous embodiment of the invention, the PTMT fibers are therefore treated at a dyeing temperature between approximately 80 and approximately 110 ° C. The treatment temperatures are very particularly preferably between 90 and 100 ° C.

In the dyeing process according to the invention, an outstandingly uniform distribution of the dyes in the fiber is achieved. The dyes in particular penetrate very quickly into the interior of the fiber. Based on the diameter of the fiber to be dyed, the disperse dyes penetrate into it at least to a relative depth of 5%. The fibers are particularly advantageously completely dyed under the dyeing conditions according to the invention, in contrast to polyethylene terephthalate fibers, which are dyed only in a ring in comparison under identical dyeing conditions.

Dyed PTMT fibers obtainable by the dyeing process according to the invention can be used in many ways. Basically, they can be used in all sectors that were also open to previously known colored polyester fibers. The dyed PTMT fibers obtainable in a process according to the invention are preferably used for the production of woven fabrics, knitted fabrics or knitted fabrics. Because of the excellent mechanical properties of colored PTMT fibers, especially the high ones Elasticity and restorability are also preferred for use in heavily used textiles or as highly elastic fabrics.

The invention is explained in more detail below with reference to the attached figures using examples. Show in the figures

Figure 1: an exemplary temperature and pressure curve in the synthesis of polytrimethylene terephthalate;

FIG. 2: for the dye C. I. Disperse Blue 139, the dye absorption as a function of the dyeing temperature for polytrimethylene and polyethylene terephthalate fibers;

Figure 3: for the dye C. I. Disperse Red 60, the dye absorption depending on the

Dyeing temperature for polytrimethylene and polyethylene terephthalate fibers;

Figure 4: Staining pattern of PTMT and PET fiber polymers with the same dyeing time with C.I. Disperse Blue 139 depending on the dyeing temperature, represented by shades of gray;

Figure 5: Staining pattern of PTMT and PET fiber polymers with the same dyeing time with C.I. Disperse Red 60 depending on the dyeing temperature, represented by shades of gray;

Figure 6: Fiber cross sections of fibers dyed at 95 ° C with C.I. Disperse Blue 139; Polytrimethylene terephthalate (left) and polyethylene terephthalate (right);

Figure 7: Cross-sections of fibers with at 120 ° C

CI Disperse Blue 139 are colored; Polytrimethylene terephthalate (left) and polyethylene terephthalate (right); and

Figure 8: the penetration depth of the dye C. I. Disperse Blue 139 as a function of the dyeing temperature for polytrimethylene and polyethylene terephthalate.

Production of the polymers

The production of the polytrimethylene terephthalate was carried out on polycondensation plants with 2 or 20 dm ^ capacity.

Approach: dimethyl terephthalate 45 mol 8739 g

(Fiber grade from Hüls)

1.3 propanediol 10.125 mol 7705 g

(Degussa AG) titanium tetrabutylate 27 mmol 9.19 g

(Sdpkt: 155 ° C at 0.015 Tor) n-butanol 83.7 g

(Sdpkt: 117 ° C, water content <0.01%)

The batch size is 45 mol, based on the dimethyl terephthalate used, the ratio 1,3-propanediol

(Diol batch D with a 1,3-propanediol content of 99.96%, 0.011% 3-hydroxymethyltetrahydropyran content, 0.005% 2-hydroxyethyl-1, 3-dioxane content, 0.02% carbonyls and 0.04% water content) to dimethyl terephthalate is added 1: 2.25 selected and titanium tetrabutylate comes as 10 wt .-%

Catalyst solution in n-butanol in a concentration of 600 ppm with respect to dimethyl terephthalate.

Transesterification:

Dimethyl terephthalate, 1, 3-propanediol and the catalyst solution are introduced into the polycondensation apparatus and heated to 140 ° C. under a constant gentle stream of nitrogen. After that Dimethyl terephthalate has melted, the stirrer is switched on and the temperature is raised to 220 ° C. The methanol released during the transesterification is distilled off until the calculated amount is almost reached.

Polycondensation:

The pressure in the polycondensation apparatus is gradually reduced and the 1,3-propanediol used in excess and the 1,3-propanediol formed during the condensation are distilled off. The temperature is slowly increased to 270 ° C and the pressure is further reduced until finally oil pump vacuum (p <0.05 mbar) is reached. The end of polycondensation is reached when the dropping rate of the 1,3-propanediol has dropped below 0.5 drops per minute. This information applies to the 2 dm ³ polycondensation plant. The power consumption of the

The agitator motor was used in the 2 dm ³ system as an indirect measure of the progressive condensation. In the 20 dm ³ system, the torque is determined as a measure of the progress of the polycondensation. The vacuum in the polycondensation apparatus is released and the finished polytrimethylene terephthalate under

Nitrogen excess pressure is discharged into a water bath with a gear pump, drawn off with a draw-off device and immediately granulated.

The reproducible temperature control during the synthesis is guaranteed by a microprocessor-controlled temperature program. The other conditions such as pressure and stirrer speed are changed manually according to the same time program.

The end of the polycondensation was determined in preliminary tests by means of torque absorption on the stirrer shaft; the torque increases with increasing molecular weight and passes through a temperature-dependent maximum. After passing through the maximum value, the torque drops again, since the degradation reaction now runs faster than that Chain construction. The optimal condensation time for the respective temperature is determined and kept constant in the subsequent tests.

A drop in temperature with a reaction time of approximately 210 minutes can be seen in FIG. The reason for this is the rapid distillation of large amounts of 1,3-propanediol, with more energy being withdrawn from the reaction mixture than can be supplied to it from the outside by the heating.

It is also noteworthy that the predetermined end temperature of the polycondensation apparatus is 240 ° C. This temperature is reached 75 minutes before the end of the polycondensation and then kept constant until the end of the polycondensation. However, as can be seen from FIG. 1, the melting temperature rises to the end of the

Polycondensation continues continuously up to 267 ° C. The heat required for this is not supplied from the outside by the heating, but is generated by the heat of stirring in the apparatus itself. The fact that this effect only occurs towards the end of the polycondensation can be explained by the steadily increasing viscosity of the polycondensation melt.

A number of polymers are produced in the manner described. The most important properties of the polymers used in the subsequent spinning tests are listed in Table 1.

Table 1

PolymerCharge COOH L * a * b *

(g / mol) [meq / kg]

A) PTMT 20/14 49 700 34 69 -1.8 +6.7

PTMT 20/11 50400 35 69 -1.6 +7.4

PTMT 20/13 51000 27 70 -1.5 +5.8 B) PTMT 20/12 53 100 29 70 -1.7 +6.2

PTMT 20/18 55200 • 24 69 -1.7 +5.7

PTMT 20/19 55 900 26 69 -1.6 +5.9

C) PTMT 20/15 57300 26 70 -1.8 +6.4

PTMT 20/16 59400 25 70 -1.7 +5.6

PTMT 20/17 60 100 25 69 -1.7 +5.3

PET Rhodia Standard: 34 matt granules M _n = 20500

The analytical data in Table 1 were obtained as follows:

Molecular weight (M ^ (g / mol)):

The weight average molecular weight is determined using static light scattering. For this purpose, polymer solutions of concentrations 2, 4, 6, 8 and 10 g / 1 in 1, 1, 1, 3, 3, 3-hexafluoroisopropanol are prepared. The filtered solutions are brought into the beam path of a helium laser (λ = 633 nm) at 20 ° C and the intensity of the scattered light is determined as a function of the observation angle. Toluene is used as the standard for determining the optical constant and for tempering the samples. The scattered light intensities are in

Dependence on the angle and the concentration plotted in a Zimm diagram.

There is a device from the Societe francaise d 'instruments de contrδle et d'analyses; Photogonio / diffusoetre from Wippler & Scheibling.

The refractive index increment is determined using the Wyatt Opilab 903 Interferometric Refractometer Technology Corporation.

Carboxyl end groups (COOH [meq / kg]):

To determine the carboxyl end group content, 4 g of polymer are dissolved at 80 ° C. in 70 ml of a solvent mixture of phenol / chloroform = 1: 1 (g / g). After cooling to room temperature, 5 ml of benzyl alcohol and 1 ml of water are added, and the solution is conductively titrated with 0.02 normal benzyl alcoholic potassium hydroxyl solution. The potassium hydroxyl solution is added continuously with a Dosimat 665 from Methrom and the conductivity is monitored with a DIGI 610 from WTW, to which a conductivity measuring cell (cell constant: 0.572) is connected.

Color measurement (L *, a * and b *):

The color of the polymers is specified using the CIELAB color values. The polymer granules are measured with the Minolta CR 310, whose spectral sensitivity is closely matched to the CIE 2 ° normal observer function. The measuring field diameter is 5 cm and the calibration is carried out using a white standard.

Manufacture of the fibers

Drying

Before the spinning tests, the polymers are dried in batches of about 25 kg each in a tumble dryer with a capacity of 100 dm ³ from Henkhaus Apparatebau. The polymer batches PTMT 20/14 + PTMT 20/11 + PTMT 20/13, PTMT 20/12 + PTMT 20/18 + PTMT 20/19 as well PTMT 20/15 + PTMT 20/16 + PTMT 20/17 mixed to obtain mixed batches A), B) and C) (see Table 1).

Table 2 shows the drying conditions.

Table 2:

1 hour 80 ° C [130 ° C] p <0.2 mbar

1 hour 100 ° C [130 ° C] p <0.2 mbar

10 hours 165 ° C [180 ° C] p <0.2 mbar

The temperatures given in square brackets refer to the drying of polyethylene terephthalate, which is processed into fibers under conditions similar to those of polytrimethylene terephthalate.

The tumble dryer is then allowed to cool to room temperature over 12 hours and aerated with nitrogen.

The water contents of the dried polymers are below 0.0025%, so that significant polymer degradation in the melt spinning process can be ruled out.

Melting spinning:

In the spinning tests, a structure and properties of fibers made from polyethylene / polybutylene terephthalate mixtures is produced by the T.I. 1989, Univ. Stuttgart, described spinning system used.

Spinning machine: extruder screw: 30 mm; 25 D

Spinnerets: 32 x 0.20 mm (32 x 0.35 mm)

Spinning pump: 2.4 cm ³ / rev spinning temperature: 250 ° C [290 ° C]

Winding speed: 2000 to 5000 m / min When an aqueous preparation ^'emulsion of 10% Limanol PVK and 1.6% Ukanol R is used. The preparation overlay is about 0.5%.

The density of the polymer melt must be known in order to produce defined spinning titers. The same applies to a defined preparation pad:

Polytrimethylene terephthalate: p 250 ° C = 1.09 g / cm ³

Polyethylene terephthalate: p 290 ° C = 1.29 g / cm ³ Preparation solution: p 20 ° C = 0.923 g / cm ³

In addition to polytrimethylene terephthalate, commercially available polyethylene terephthalate was also spun in the spinning tests. The spinning speeds are varied at a spinning titer of 16 tex with 32 individual filaments in the range from 2000 to 5000 m / min. The spinning titer is varied at a constant spinning speed of 3500 m / min in the range from 9.6 to 22.4 tex with 32 individual filaments each. This corresponds to a fineness of 0.3 to

0.7 tex per single filament.

In the case of polytrimethylene terephthalate, the spinning temperature is varied in the range between 240 and 270 ° C, with the best results being achieved at 250 ° C. In addition, different spinnerets with nozzle hole diameters of 200 to 350 μ are used for polytrimethylene terephthalate. The best results are achieved with a 200 μm nozzle.

The staple fibers obtained are drawn on a stretching system from Diens Apparatebau. The stretching factors are chosen so that the drawn fiber has about 25% elongation. The mechanical properties of the staple fibers and the drawn fibers made of polytrimethylene and polyethylene terephthalate are listed below:

Polytrimethylene terephthalate staple fibers:

Spinning speed- Titer maximum tensile force initial module elongation [tex] [CN / dtex] [CN / dtex] [%]

[m / min]

2000 15.9 1.68 19.9 139

2500 16.1 1.97 20.8 107

3000 16.1 2.25 22.0 85

3500 16.1 2.48 23.2 68

4000 16.3 2.59 23.6 60

4500 16.3 2.53 23.3 59

5000 15.8 2.59 22.9 55

3500 9.6 2.54 23.2 68

3500 12.9 2.49 23.0 68

3500 16.1 2.48 23.2 68

3500 19.4 2.44 22.7 67

3500 22.7 2.34 22.4 64

Drawn polytrimethylene terephthalate fibers:

Spinngeschwin¬ stretch-stretch high module elongation factor titer tensile force [CN / dtex] [%]

[m / min] [tex] [CN / dtex]

2000 1.78 9.0 2.76 24.1 42

2000 1.90 8.8 2.92 24.3 38

2000 2.00 8.4 2.97 24.8 32

2000 2.11 7.9 3.20 26.2 26

2000 2.20 7.9 3.34 24.6 24

2000 2.32 7.2 3.75 26.8 22

2000 2.41 7.1 3.98 27.1 20 Drawn polytrimethylene terephthalate fibers:

Spinning speed • stretching-stretching-high modulus elongation factor titer tensile force [CN / dtex] [%]

[m / min] [tex] [CN / dtex]

2000 2.16 7.9 3.26 24.7 26

2500 1.87 9.2 3.43 25.1 26

3000 1.66 10.4 3.52 25.3 24

3500 1.44 12.1 3.29 25.5 25

4000 1.37 12.8 3.38 25.4 26

4500 136 12.8 3.34 25.1 25

5000 1.35 13.1 3.35 25.4 27

3500 1.44 7.1 3.49 25.8 24

3500 1.44 9.6 3.41 25.8 25

3500 1.44 12.1 3.29 25.5 25

3500 1.44 14.5 3.29 26.0 24

3500 1.44 16.8 3.24 24.4 22

Polyethylene terephthalate staple fiber:

Spinning speed- Titer maximum tensile force initial module Dehnu: digkei [tex] [CN / dtex] [CN / dtex] [%]

[m / min]

2000 15.8 1.82 21.3 156

2500 15.8 2.07 23.5 131

3000 15.3 2.29 27.1 110

3500 15.9 2.55 33.3 93

4000 15.9 2.67 41.2 79

4500 15.6 2.86 51.4 68

5000 14.8 3.21 60.2 60

3500 9.6 2.63 40, 6 89

3500 12.8 2.56 37.2 90

3500 15.9 2.55 33.3 93

3500 19.0 2.54 32.9 93

3500 22.2 2.46 31.4 93 Drawn polyethylene terephthalate fibers:

Spinning-speed-stretch-titer maximum module elongation factor [tex] tensile force [CN / dtex] [%] [m / min] [CN / dtex]

2000 1.79 8.9 3.45 68.1 43

2000 1.88 8.5 3.75 76.7 38

2000 1.98 8.1 3.93 82.8 31

2000 2.08 7.8 4.01 91.5 24

2000 2.20 7.4 4.26 104.0 17

2000 2.29 7.1 4.50 108.7 9

2000 2.42 6.8 5.25 117.2 6

2000 2.07 7.8 4.10 97.5 24

2500 1.85 8.7 4.08 100.2 25

3000 1.69 9.2 4.20 103.0 24

3500 1.55 10.5 4.21 103.3 26

4000 1.46 11.1 4.19 106.8 26

4500 1.38 11.6 4.06 105.1 25

5000 1.31 11.5 4.34 112.6 25

3500 1.55 6.4 4.26 110.5 24

3500 1.55 8.4 4.31 108.0 25

3500 1.55 10.5 4.21 103.3 26

3500 1.55 12.6 4.17 102.3 25

3500 1.55 14.6 4.15 101.8 25

Staining attempts

The glass transition temperature of the polymers in aqueous medium is of greater importance for the dyeing behavior of the synthetic fibers. DR Buchanan and JP Walters, text. Res. J., 42 (1977), 398, define a color transition temperature. For this purpose, the dye absorption of the synthetic fibers is determined as a function of the temperature. The temperature at which the dye absorption is 50% of the equilibrium value is defined as the coloring transition temperature. However, the dyeing transition temperature depends on the dyeing time and the dye structure.

Substrates:

The use of fiber flake in dyeing tests has the disadvantage that the fibers can knot and then can no longer be washed around uniformly by the dye liquor. The uneven dyeings obtained from this cannot be used to determine the dye content. The dyeing tests are therefore carried out using knitted fabrics made from stretched fibers. A circular knitting machine of the Elba type from the Lucas machine factory was used to manufacture the knitted fabrics into a knitted tube (diameter 10 cm).

Knitted fabrics made from the following fibers are used for the dyeing tests:

Polymer spinning speed spinning titer stretch factor stretch titer [tex] [tex]

[m / min]

PTMT 3500 16.1 1.44 12.1

PET 3500 19.0 1.55 126

In order that the stretch titer and thus the fiber diameter of the fibers to be dyed are comparable, a higher spin titer was chosen because of the different stretch factors for the polyethylene terephthalate fiber.

The fibers are knitted on a

Circular knitting machine washed to remove the preparation applied during spinning. Pretreatment:

To remove the spin finish, the knitted fabric is washed as follows:

Washing conditions: Apparatus: Mathis LAB Jumbo Jet with washing drum

Temperature: 30 ° C Duration: 120 min Wash liquor: 1 g / 1 Kieralon® EDB from Bayer AG

Fleet ratio 1:50

To avoid shrinkage during dyeing and to improve the dimensional stability of the knitted fabrics, they are heat-set at 180 ° C. for one minute. The tensions in the fiber that arise during stretching are relaxed. The thermofixed knitted fabrics show the

Polytrimethylene terephthalate has a greater surface shrinkage than with polyethylene terephthalate.

Fixing conditions: Apparatus: Mathis dryer temperature: 180 ° C

Duration 1 min

Dyes:

Two disperse dyes are selected that differ significantly in their diffusion coefficient: Dye diffusion coefficient

[10 10 cm ^

C.I. Disperse Blue 139 0.8 mono-azo dye resolin marine blue GLS from Bayer AG

C.I. Disperse Red 60 3.4 antrachinone dye Resolin Red FB from Bayer AG

The extinction coefficient of the pure dye must be known for the quantitative determination of the dye absorption. The cleaning of the above-mentioned disperse dyes is described in detail by E. M. Schnaith (dissertation 1979, Univ. Stuttgart).

The dyeing temperatures are varied between 60 ° C and 140 ° C.

The coloring is always started at 40 ° C and the heating rate selected so that after 45 minutes

Dyeing temperature is reached. The cooling rate is always 1 K / min until the bath temperature reaches 40 ° C.

Staining conditions:

Dyeing machine: Ahiba Polymat dyeing time: 60 min liquor ratio 1:20 liquor: 1 g / 1 dye

2 g / 1 Avolan® IS from Bayer AG 2 g / 1 sodium dihydrogen phosphate dihydrate Reductive post-treatment:

The dyeings are reductively treated to remove the dye that has deposited on the fiber surface. The heating rate of the reduction liquor is 2 K / min, the cooling rate is 1 K / min.

Reduction conditions:

Apparatus: Ahiba Polymat temperature: 70 ° C liquor ratio: 1:20 liquor: 3 g / 1 sodium dithionite

1.2 g / 1 sodium hydroxide

1 g / 1 Levegal® HTN from Bayer AG

Finally, the knitted fabric is acidified with 5% formic acid.

Dye uptake:

To determine the dye absorption, the fibers dyed at different temperatures are extracted exhaustively with chlorobenzene. The extracts are diluted to a defined volume and the extinctions of the solution are determined with the aid of a Lambda 7 UV / VIS spectrophotometer from Perkin Elmer in Bodensee. From the extinction of the extraction solution at the characteristic wavelength

C.I. Disperse Blue 139 604 nm and C.I. Disperse Red 60: 516 nm

the dye content can be determined using the corresponding calibration line. The dye content FG in g / kg of goods is determined using the numerical equations:

C.I. Disperse Blue 139:

Volume of extraction E + 3.2 x 10 ^{~ 3} solution [ml]

FG [g / kg goods] = x

0.05948 mass of extracted

Sample [mg]

C.I. Disperse Red 60

Volume of the extraction + 4.67 x 10 ^"4 solution [ml]

FG [g / kg goods] = x

0.04115 mass of sample extracted [mg]

Figures 2 and 3 show the dye uptake of polytrimethylene terephthalate fibers as a function of the dyeing temperature in comparison to polyethylene terephthalate fibers.

In Figures 2 and 3, the horizontal line marks the amount of dye in the dye liquor based on the amount of substrate used.

From Figure 2 it can be seen that the dyeing of the polytrimethylene terephthalate fiber begins at about 70 ° C, while the polyethylene terephthalate fiber is noticeably colored only at temperatures above 90 ° C.

The maximum determinable dye absorption is around 95% of the maximum possible dye absorption, since the fiber samples are reductively aftertreated before the extraction. The dye adhering to the fiber surface is reductively destroyed and the maximum determinable dye content is thereby reduced. Fig. 2 also shows that at a dyeing temperature of 100 ° C, the entire dye from the dye liquor on the polytrimethylene terephthalate fiber. On the other hand, at a dyeing temperature of 100 ° C, only about 15% of the dye offered is absorbed by the polyethylene terephthalate fiber.

The dyeing temperature must be increased to 130 ° C in order for the dye to be completely absorbed onto the polyethylene terephthalate fiber. This has the consequence that the bath-exhausting dyeing of the polyethylene terephthalate fiber must be carried out in closed vessels under pressure (HT dyeing conditions).

With C.I. Disperse Red 60, a disperse dye with a higher diffusion coefficient, an almost identical course of dye uptake with the dyeing temperature can be observed as with C.I. Disperse Blue 139.

In the case of the CI Disperse Red 60, however, the curve is shifted by about 5 to 10 K to lower temperatures than in the CI Disperse Blue 139. This fact can be explained with the higher diffusion coefficient of the CI Disperse Red 60, since the dye molecules diffuse faster into the interior of the fiber can.

Dyes with C.I. Disperse Red 60 show a maximum dye absorption of the polytrimethylene terephthalate fiber from a dyeing temperature of 95 ° C.

For polyethylene terephthalate fiber, the maximum

Dye uptake only reached at 120 ° C dyeing temperature, so that here too the bath-exhausting dyeing must be carried out in closed apparatus under pressure.

The color transition temperature of polytrimethylene and

Polyethylene terephthalate are therefore: PTMT PET

C. I. Disperse Blue 139 91 ° C 107 ° C C. I. Disperse Red 60 84 ° C 100 ° C

The dye transition temperature is about 7 K lower than in the case of dyeing both polymers with C.I. Disperse Red 60, due to its higher diffusion coefficient

Colorings with C.I. Disperse Blue 139. However, the difference of 16 K in the color transition temperatures of the two polymers remains constant.

4 and 5 show dyeing patterns of both fiber polymers with the same dyeing time depending on the

Dyeing temperature. The difference in dye absorption is best seen here. The color intensity differences are represented by shades of gray.

Dye distribution:

The dye distribution in the fiber can be assessed using fiber cross-sections. A distinction can be made between solid colors and ring colors. Fiber cross sections are obtained by embedding the fibers in acrylic acid esters and cutting them to a thickness of 10 μm with a Minot microtome from Jung. The cross-sectional images are taken with a Zeiss Axioplan microscope. The authenticity of a dyeing, when the dyed fabric is subjected to abrasion, is higher in the case of dyeing through than in the case of ring dyeing, in which the dye is only embedded in the outer layer of the fiber.

For the cross-sections, stains with CI Disperse Blue 139 were chosen because this dye is very has low diffusion coefficients. When using other dyes with higher diffusion coefficients, a full coloration can be expected even at lower dyeing temperatures.

6 and 7 show cross sections of polytrimethylene and polyethylene terephthalate fibers which are dyed at 95 ° C. and 120 ° C. with C.I. Disperse Blue 139.

In the case of polyethylene terephthalate fiber, the titanium dioxide particles with which the polymer granulate used is matted can be seen.

The cross sections of the fibers show that the dye can penetrate the interior of the polytrimethylene terephthalate fiber more quickly than is the case with the polyethylene terephthalate fiber.

Fig. 8 shows that related to the fiber diameter

Depth of penetration of the dye depending on the dyeing temperature.

Comparing FIG. 8 with FIG. 2, the following can be determined:

The polytrimethylene terephthalate fiber can be

Excellent color for cooking temperature with C. I. Disperse Blue 139. The fiber absorbs all of the dye offered in the dyeing liquor. The dye concentration is highest in the peripheral areas. In the case of HT dyeing, the dye diffusion is accelerated so that a uniform dyeing can be observed over the entire fiber cross section.

In contrast, the dye absorption of the polyethylene terephthalate fiber at cooking temperature is significantly lower. The dye absorption of the fiber is only 10% of the dye offered in the dye liquor. The polyethylene terephthalate fiber can also be used under HT conditions stain well. All of the dye on offer penetrates the fiber, but there is no discoloration of the fiber with CI Disperse Blue 139.

Further advantages and embodiments of the invention result from the following patent claims.

Claims

claims

1. Process for dyeing fibers of the

Polytrimethylene terephthalate (PTMT fibers), in which the PTMT fibers are treated in an aqueous liquor containing at least one disperse dye at or below the boiling temperature of the liquor, characterized in that the PTMT fibers are dyed without pressure and without a carrier, the dyeing being carried out at a Liquor temperature between 20 and 50 ° C is started, the temperature within 20 - 90 min, preferably within 45 min, brought to the boiling temperature of the liquor or to a dyeing temperature which is at most 20 ° C below the boiling temperature of the liquor, the coloring at least 20 minutes at the dyeing or boiling temperature, preferably 30-90 minutes, and then cooling to a temperature of 20-50 ° C., preferably at a cooling rate of 1 ° C. per minute, so that at least 95% by weight % of the dye offered in the fleet absorbs onto the PTMT fibers, and the disperse dye at least in a relative Ti efe of 5% based on the diameter of the fiber to be dyed penetrates into it.

2. The method according to claim 1, characterized in that a liquor is used which has between 3.0 and 7.0 g of pure disperse dye per kg of PTMT fiber to be dyed.

3. The method according to claim 2, characterized in that a fleet containing Disperse dye of 4.5 to 5.5 g pure dye / kg PTMT fiber is used.

4. The method according to any one of the preceding claims, characterized in that at a dyeing temperature between 80 and 110 ° C, preferably between 90 and 100 ° C, is treated.

5. The method according to any one of the preceding claims, characterized in that the fibers are dyed through.

6. Use of dyed PTMT fibers obtainable in a process according to one of the preceding claims for the production of woven fabrics, knitted fabrics or knitted fabrics.