DE1694476B - Polyamide thread - Google Patents

Description

In British patent specification 1 126 213 it is stated that by incorporating certain organic nucleating agents, preferably polymeric nucleating agents, into polyamides melt-spun undrawn threads can be obtained which have defined X-ray parameters, which parameters are the difference between the orientation factors O ₁ and O _{0 of} the above spun threads are expressed. So O ₁ -O _{0 should be} greater than 0.2. By melt-spinning nucleating agent-containing polyamides into filaments with the above-mentioned X-ray parameters and then orienting the filaments by conventional drawing processes, a significant increase in the productivity of spinning is achieved. This increase in productivity can be expressed as the productivity ratio (PV), which is defined as follows:

P. V. =

Verstreek ratio, which has a 30% elongation at break at a

containing thread results

lubricants

Draw ratio, which is a 30% elongation at break with no nucleating agent

containing thread results

The P.V. is only used in processes with high spinning speeds as a measure of the increase in the Productivity used, d. H. in processes where speeds are above approximately 610 m / min can be used. In processes where normally low spinning speeds, d. H. about 457 m / min or less can be used, productivity can be increased by increasing it the spinning speeds can be increased.

It has now been found that certain inorganic materials can also be used as nucleating agents in Polyhexamethylene adipamide or in another polyamide with a comparable linear crystallization rate can be used and result in melt-spun undrawn filaments having the X-ray parameters given above with a similar increase in productivity. It was further found that the Incorporation of these nucleating agents leads to threads of improved quality; for example can a yarn with a more uniform denier and with more uniform dyeing properties over the whole Length can be obtained.

Finally, it was also found that the particle spacing of the nucleating agent in the polyamide mentioned is an important criterion with regard to achieving uniform nucleation of the polyamide with inorganic nucleating agents. For example, with nylon-6.6, effective nucleation is achieved over a wide range of spinning speeds if the average distance between the particles of the nucleating agent in the polyamide, hereinafter referred to as the average nucleating agent particle distance, is less than 1μ. An even more advantageous nucleation is obtained. when the average nucleating agent particle size is less than 0.5 μ. Unless otherwise stated. The nucleating agent particle distances given below relate to values calculated from the weight concentration of the nucleating agent in the polyamide and the average diameter of the nucleating agent particles used in the production of the nucleating polyamide. The mean diameter of the middle particles. for example in an aqueous suspension, can be measured using an electron microscope at a magnification of 99,000 times. At this magnification, I cm corresponds to 0.1 μ. so that, for example, with a centimeter lincal, the size of each particle ^ft 5 can easily be measured to 0.005 μ. A convenient method is to photograph a dilute suspension of the particles and then measure the size of each particle in Λγ photography, from which the mean diameter of the particles can then be calculated.

The average nucleating agent particle distance in the polyamide calculated in the above manner agrees well with the value obtained by direct examination of cross-sections of nucleated Yarns is obtained using the electron microscope.

One factor that affects nucleating agent particle spacing in achieving efficient nucleation Affected is the rate of crystallization of the polyamide, and the maximum nucleating agent particle distance can as a function of the crystallization rate of the polyamide according to can be expressed in the following theory.

Solidify freshly spun filaments obtained by melt extrusion of a polyamide usually rapidly turns into a non-crystalline, supercooled, glassy structure on cooling, whereby the solidification point is somewhat arbitrary and can be referred to as the point at which in the A steady titer is obtained in the cooling zone. This type of cooling can lead to solidification of the polyamide are markedly influenced by external cores, which are generally known gloss effects in the spun threads and can cause variable yarn properties. It was found, that by the addition of a finely divided inorganic crystallization nucleating agent in sufficient Amount of solidification point of the threads just spun through solidification mediating Crystallization can be both increased and stabilized.

When the freshly extruded thread is underneath the melting point cools down, then the crystal fronts move with the crystallization nuclei a speed forward that depends on the temperature depends, and if the crystal faces of neighboring nuclei, which by an average Distance S are separated from each other, meet, then the polymer is solidified. So with that the addition of an inorganic nucleating agent is effective, sufficient cores must be present be in order to fill the yarn with a linear crystal growth before the thread turns into a glassy one State is deterred. The required concentration of inorganic nucleating agent for a given particle size can be determined if the maximum spherulite size in a melt spinning process, which uses a polymer in which no nucleating agent has been incorporated is known. This maximum spherulite size

| ann from the measured spherulite growth rates as a function of the temperature and the time-temperature relationship of the threads at fipinnen are measured. This is how the Spharolithladius becomes by numerically integrating the expression

G (T) dt

where G (T) is the spherulite growth rate at temperature T. The integration is carried out between the spinneret plate and the solidification point, which is defined as the point at which a permanent titer η ik-r cooling zone is reached and which is determined from experimental pull-down curves of the threads spun from the polyamide in question.

The amount of inorganic nucleating agent required (Iiυ to achieve the desired effect can therefore be defined with the maximum distance 2 'from the individual inorganic nuclei will. Thus is the maximum nucleation columnar distance S, in which solidification by crystallization takes place earlier than solidification by undercooling, by the expression

xc

<lic

/ \ llfspill-
jeseh ^ indiii-
wedge Tiler des
spun
load> .VC [rrechneler
Spherolite Maximum
Nucleic
ation
inillel- m: iun in the ahsMnd S 1341 Il 50 0.44 µ. 0.88 µ 268 62 45 0.65 µ. 1.30 µ

Proposed polyamide with a linear crystallization rate of the same order of magnitude, which contains a nucleating agent and optionally a matting agent, and in the unstretched state has a molecular orientation that gives an X-ray reflection diagram in which O ₁ - O _{1 is} greater than 0.2, which is characterized that the nucleating agent is inorganic in nature and has an average particle size of less than 0.5 microns and is present in a concentration that the maximum nucleating agent particle distance by the expression

G df

where ί is the line from the spinneret plate and XC is the distance from the spinneret plate of the nucleated solidification point when melt spinning in filaments.

The above expression is used to calculate the mean maximum nucleating agent spacing used for N'ylon-6.6, which occurs at two different Spinning speeds has been spun. where the equation

36 2 47 500

used to increase the spherulite growth rate G (T ") to be calculated, where G in μ per see and / is expressed in C. The above equation is from the equation of J. H. M ag ill. Polymer, Vol. 6, July 1965. p. 367. derived. Details of the two different spinning attempts are in given in the following table.

The results suggest that within this range of spinning conditions for nylon-6.6, the Nucleating particles should be spaced about 1μ or less apart, which works well with the in corresponds to the experimental figures given in the series and what also applies to other polyamides, the crystallization rates are of the same order of magnitude as nylon-6,6.

According to the invention, a thread made of Polyhxamethylcnadipamid or another XC

S <2

is given in which

G is the linear crystallization rate m

μ / sec at temperature T ⁰ C ,
S is the maximum nucleating agent particle distance,

XC is the distance of the solidification point from the spinneret plate for an unnucleated polyamide is when this is melt spun into threads, and

f is the time in seconds it takes a point on the thread to travel from the spinneret plate to a point X , where X is any point between XC and the spinneret plate.

Preferably is the mean spacing of the nucleating agent particles smaller than 1 μ and in particular smaller than 0.5 μ.

Filaments which are spun from the above-mentioned polymer are normally then subjected to a cold stretching experience in order to achieve a molecular orientation. Certain difficulties may be encountered during this stretching process and it is therefore preferred that the polymer contain at least 0.03 weight percent of a matting agent to facilitate cold stretching. At least 0.2 percent by weight matting agent, such as. B. TiO ₂ , should be added in order to achieve a significant degree of matting.

It is preferred to use polyhexamethylcnadipamide, but other polyamides with crystallization rates in the same order of magnitude, such as B. polyoctamethylnadipamide and polydccamethylene adipamide. can also be used successfully.

The most preferred inorganic nucleating agent is calcium fluoride (CaF ₂ ). Also effective inorganic nucleating agents are: Talc. Pyrophyllite, agalite, ash line, antimony trioxide, molybdenum disulphide. Graphite or lead tungsten.

Oi and O " are calculated from measurements made with the large-angle X-ray Laiic diagram obtained from the filaments.

The Laue diagram showing the fiber has two main rings, an inner and an outer Ring, which are reflections from the main paratropic lattice planes of the crystal structure. The intensity these rings (M) on the meridian --- the meridian is a straight line on the X-ray film that is parallel

I 694476

the direction of the grain and through the location of the primary x-ray runs - and (E) at the equator - the equator is a straight line on the X-ray film, which runs perpendicular to the fiber direction and through the position of the primary X-ray beam runs through - can be determined, and

Orientation factors t ^ tf can be calculated. For convenience, these orientation factors are labeled Oj for the inner ring and O ₀ for the outer ring.

The values for O ₁ and O ₁ are determined in the following manner.

The yarn sample is wound up as a parallel fiber bundle on a simple sample holder, which then is brought into an evacuable X-ray camera, (in such a way that the bundle is perpendicular 711m primary X-ray lies. A flat sheet of film is placed perpendicular to the primary beam and on top of the x-ray source opposite side of the fibers arranged so that he has the diffraction diagram of the Can receive fibers. The primary beam is directed to cover the film near the center: n the usual way. The camera will run for a minimum of 5 minutes a vacuum better than 0.2 mm Hg) is evacuated, and each sample is 15 minutes at 40 KV and 15 mA exposed, the camera being continuously evacuated during the exposure. There will be a Ni-fil Trated Cu · Ka radiation from a sealed X-ray tube used, which was connected to a Phillips PW-1008/30 generator is operated.

The exposed film is developed as follows: 5 minutes in Ilford PQX-1 x-ray film developer ib at 20 C). what a 30 minutes or longer continuous washing follows in order to achieve a maximum optical density of the film of approximately 1.0 achieve.

Using a Joyce-Loebl writing double-beam microdensitometer (Model E. 12 Mk. III) diametrical scans are made over the equator and the meridian. The two Measurements are written out superimposed on one another on a recording strip. The usual underground will be billed before the integrity measurements (£ or M) at the equator and at the meridian for the two main reflections.

The ratios

^ f

f. and \ _t ^ f then become

50

definitely.

The nucleation means can be used in an advantageous manner be incorporated into the polyamide during the polymerization of the salt. For example, a Calcium fluoride brci can be injected into an autoclave during the polymerization of nylon salt, and although preferably during a period of 10 to 25 minutes at an autoclave temperature of 225 ° C and a pressure of 17.5 at. On the other hand, the calcium fluoride brci can also be inserted into the spiral & o Injecting a continuous polymerizer, preferably at one point after 60% of the length of the evaporator section. The nucleating agent can be used in situ (e.g. under Use of calcium adipate and hexamethylenediammonium dihydrofluoride) be prepared in the autoclave or spiral polymerization process. The nucleating agent can also be coated by carving be incorporated into the polyamide with an aqueous paste.

The inorganic nucleating agents must be in a finely divided state, that is to say that they have an average diameter of less than 0.5 μ. Preferably, d ^p .r average diameter should be less than 0.1 μ and in particular less than 0.05 μ.

The concentration by weight of the inorganic nucleating agent in the polyamide to be used depends on the particle size of the material and should be chosen so that the maximum Nucleating agent particle distance does not exceed the value given by the expression

.ve

2 yrs

given is.

Effective nucleation of nylon-6,6 is achieved through the use of only 0.008 weight percent Calcium fluoride achieved with an average particle size of 0.03 μ, but a more effective one Nucleation is achieved when the concentration of this nucleating agent is at least 0.66 percent by weight amounts to. These percentages by weight of calcium fluoride correspond to an average Nucleating agent particle spacing of 1 or 0.5 u.

The preferred inorganic nucleating agent. Calcium fluoride can be obtained in a suitable fine particle size by the well-known method of double reacting a suitable calcium salt with a suitable fluoride salt in aqueous solution. For example, solutions of calcium acetate and potassium fluoride can be mixed at or near the boiling point, whereupon the precipitated calcium fluoride is filtered off or separated off by centrifugation. The particle size of the calcium fluoride obtained by this process changes with the precipitation temperature. At 60 ° C., a particle size in the range from 0.01 to 0.1 μ and at 100 ^° C. in a range from 0.05 to 0.5 μ are obtained.

For example, one advantageous method is. Calcium hydroxide and hydrofluoric acid or calcium adipate and hexamethylenediamine dihydrofluoride in solution, as the by-products this implementation are water or nylon salt.

The invention is illustrated in more detail by the following examples. In these examples the concentrations are Expressed in weight unless otherwise specified.

example 1
(a) Production of nucleated polymer

348 grams of potassium fluoride was dissolved in 8 liters of distilled water at the boiling point, and a solution of 474 grams of calcium acetate in 8 liters of distilled water was similarly prepared. The two solutions were mixed slightly below boiling point and stirred for a few minutes. The mixture was then boiled for ^l / ₂ hour, and finally allowed to stand overnight. The clear supernatant layer, which accounted for approximately _^4/5 of the total volume, was decanted and the residual calcium fluoride / centrifuged for 10 minutes at 4000 rpm. The clear protruding layer that roughly

IS

ⁱ U of the volume of the centrifuged suspension was then decanted from the centrifuge tubes.

Finally, the aqueous paste, which contained 60% calcium fluoride, was placed on nylon 6.6 Schnilzel under Addition of pigment nylon in a Gardncr mixer layered so that the final polymer 1.2% Contained calcium fluoride.

(b) Spinning and drawing processes

The polymer was melted in a screw pressure melter and at a spinning speed of 1198 m / min and spun at a spinning temperature of 290 C into a 13-filament yarn.

A control yarn was used to provide comparative information in this and the following examples spun and wound under identical conditions of speed and temperature, a polymer was used which did not contain any calcium fluoride additive, but otherwise contained the possessed the same properties.

Both yarns were drawn at a drawing speed of 460 m / min and the drawing ratios were set so for each yarn. that a yarn with a titer of 40 den and with 0.4 Z twists per 25 mm and with a normal elongation at break of 30% was obtained.

(c) Properties of the spun yarn

Titer per thread (den)

O ₁

O

O ₁ -O _n

DTA freezing point. C.

Draw ratio for one

30% elongation at break. ..

Productivity ratio. . .

\ ln C'.ilciuiii- onirolk- tluorul nuklcicrl 9.2 11.2 -0.64 0.05 - 0.06 -0.41 0.02 0.46 223 237 2.92 3.89 1.33

40

45

The DTA congealing point is the congealing point of the spun yarn sample as measured by differential thermal analysis using the method described in the aforementioned German Patent is described.

Example 2
Preparation of the nucleated polymer

45.3 ka nylon-6.6 [Polyhe \ amethy! Enadipamidlpolymer with a relative viscosity of 40 and a content of 0.3 ° η TiO _: was mixed in a Gardner screw mixer with 1.13 kg of pigment nylon. Then 1.13 kg of a 0.4% strength aqueous suspension of CaF were mixed in, so that a CaF, concentration in the polymer of 0.1% was obtained. The average particle size of the CaF _: in the aqueous suspension was 0.03 · χ.

The calcium fluoride slurry was prepared as follows: 1055 a of calcium acetate (purity 91%) were dissolved in 3103 ml of demineralized water. so that a saturated solution was obtained, and 760 g of potassium fluoride (94% purity) were in 3103 ml dissolved in demineralized water. The solutions were filtered and the potassium fluoride solution was brought to the same volume as the calcium acetate solution. The nitrated solutions were then separated at room temperature and at the same volume velocities with the aid of a micropump pumped into the arms of a glass T-piece with an inner diameter of 6.3 mm, where the Stoichiometrically balanced solutions reacted and calcium fluoride precipitated. The precipitation was together with the potassium acetate solution through the open end of the T-piece into a suitable container printed. To increase the rate of the reaction, a stainless steel stirrer was inserted into the open end of the tee is introduced into the reaction zone and at a speed of 1500 rpm set in rotation.

The resulting suspension contained 500 g calcium fluoride with an average particle size of about 0.03. measured with an electron microscope at 1,000 times magnification. This suspension WiU thixotropic.

The gel suspension was diluted to give a final ' A concentration of 0.6% calcium fluoride can be achieved by making up to 83 liters with demineralized water would. The flocculated calcium fluoride was allowed to settle for 4 to 5 hours, and the supernatant clear liquid was siphoned off. The suspension was then diluted again to 0.6%. Allowed to settle for 48-04 hours, and the clear supernatant liquid was decanted off, and further demineralized water was added, again achieving a concentration of 0.6% would.

Spinning process

The polymer chips coated with CaF were transported at a speed of 680 m / min a polymer throughput of 3.5 kg hours in 12 monofilaments spun. The threads were quenched in the Spinnkamiti and after a distance of 107 cm from the spinneret plate using a; Monofilament spinning tube merged, however The spinning center line was offset from the chimney. The yarn was traversed using a traverser Strokes of 58.7 mm with one Frequer. of 700 cycles min wound, with the withdrawal tension below 6 g the suitable ': Adjustment of the angle of rotation around the finish roller and the finish rollers pens was held. Good biscuit builders were obtained that were within the range from I to 13% were independent of the moisture content. Both! used high speed passed dit There is a tendency for the spin finish applied to the threads to be thrown off. This was done by the use of a modified thread pull eliminated, with the threads over the godets in Grupper by four thread lines, each of which contained three threads, after the spin finish was applied and then on the splitter pin again into the individual threads.

Stretching

The monofilament was unte on a stretching twist at a speed of 1280 dr. Min Use of a draw ratio of 4.71 to a denier of 15 drawn. The stretched one

109 549.'49:

Monofilament was wound into package with a long-short structure. A matt chrome steel drawing pen heated to a temperature of 120 ° C was used. The draw pin surface temperature measured by a thermocouple, was '18 "C, while the yarn temperature at a distance of 25.4 or 50.8 mm below the drawing pin 94 and 91 ⁰ C, was the two temperature measurements using Hastings-Raydist temperature measuring device, Table 1 shows the relevant process data and yarn properties.

Processing in hosiery

Six packages of yarn weighing 1.36 kg that have been spun from the nucleated polymer were knitted into women's stockings. The stockings were both in appearance and in Very satisfactory use.

B ice ρ i ^p . 1 3 Example 2 was repeated, with the difference

that the percentage of calcium fluoride was increased to 0.2% (0.03 µ average particle size).

The results of this experiment are given in Table I.

Example 4

Example 3 was repeated, but using spinning speeds of 893 and 1198 m / min became. The results of this experiment are given in Table 1.

table

Spinning speed m / min 680

% CaF ₂ 0.1

Average nucleating agent

particle distance (μ) of CaF ₂ 0.43

O ₁ -0 0.51

DTA freezing point. C 235

Example 5 Production of nucleated polymers

4.53 kg of nylon 6.6 polymer chips with a relative viscosity of 36 and a content of 0.3% TiO ₂ were coated with calcium fluoride by adding a 5% aqueous dispersion of calcium fluoride (average particle size 0.03 μ) together with 1.13 kg of pigment nylon / i was mixed. The calcium fluoride concentration in the polymer is true 0.09%.

Spinning process

The polymer-coated chips were spun into a yarn, with the threads in a Distance of 120 cm from the spinneret plate and the point of convergence Was indented 50.8 cm from the chimney.

Proceed in a stretched twist

The yarn was on a draw twister at a drawing speed of 1000 m min and stretched to a stretching ratio of 4.00. A chrome-plated steel drawing pencil; was used that was heated to 100 "C. The drawn yarn had a linear density of 70 den and contained 20 threads.

Process details and the yarn properties are in Table 2 along with those of one Verification sample given.

example

680
0.2

0.33
0.54
234

843
0.2

0.33
0.60

234

1198 0.2

0.33 0.55

232

Control check

425

-0.08

225

Average particle size

of CaF ₂ (μ)

Average distance between

Particles of CaF ₂ (μ)

Draw ratio for one

30% elongation at break

O ₁ -O ₀ ■

DTA freezing point. "C

Productivity ratio

example

0.03 0.45

4.00 0.43 234 1.32

Ver

equally probc

3.03 225

Table I. example

Ver

sample

Spinning speed m / mm
CaF- ,. Weight percent

110

llU The spun from the nucleated polymer Yarn was puffed on a false twist crimper and the puffed yarn was turned into a Textile knitted. The comparison yarn, which is made of a polymer without a content of calcium fluorine was spun. was puffed in the same way and converted into a textile material. There nucleated yarn gave satisfactory bulk behavior and the fabric made from it was wa uniform and free from defects.

Example 6 Preparation of Nucleated Polymer

A calcium fluoride slurry with an average Particle size of 0.03 μ was during the Polyrm Injecting hexamethylene diammonium adipate into a spiral for continuous polymerization The spiral used for continuous pole; merization was such as it was in the british Patent 924 630 is indicated. The polyhex; methylene adipamide polymer. the calcium fluoride

1806

held, was pressed as a thick ribbon into a water bath and then shredded. The concentration of calcium fluoride in the shredded polymer was 0.06% and the relative viscosity of the polymer was 46. The polymer contained 0.2% TiO ₂ .

Spinning process

The nucleated polymer chips were turned into a yarn at a speed of 308 m / min 68 threads that have a three-lobed cross-section like - (<en. spun, resulting in a throughput of 14.9 kg / hour. corresponded. A very good thread run was obtained in the chimney. The thread wound from the spun yarn Wraps were good too.

Stretch-bulking process

The nucleated spun yarn was triple-folded and then draw-bulked. and to a stretched, uncrimped titer of 3650 den on a stuffer box crimping machine With subsequent standard fixation. The threads in the finished yarn had good cross-sectional shapes.

Process details and yarn properties are in Table 3 along with those for one Comparison yarn indicated, that of an unnucleated Polymer and was obtained at a spinning speed of 217 m / min.

Making a carpet

The triple-gathered nucleated yarn was tufted so that a loop pile carpet was obtained which was then tested with a standard mixture of red, blue and yellow nylamine test dyes was colored. A similar comparative yarn was made from a polymer with no nucleating agent processed into a carpet and dyed in a similar way. The nucleated yarn made one satisfactory carpet of which the appearance was more uniform. than that of one from the comparison yarn manufactured carpet.

Example 7

Example 5 was repeated with the difference that the concentration of calcium fluoride (average particle size 0.03 · ι) was increased to 0.132%. Process details and yarn properties are given in Table 3.

Example 8
Production of nucleated polymer

Nucleated polyhexamethylene adipamide was prepared in an autoclave with a capacity of 2270 1, wherein a Calciumfluoridbrei (average particle size 0.03 μ) slowly into the autoclave over a period of 25 minutes at an autoclave temperature of 225 ⁰ C untl ίο a pressure of 17.5 at was injected. The polymer had a relative viscosity of 40 and contained 0.2% calcium fluoride and 0.2% TiO ₂ .

Spinning process

> 5 The nucleated polymer was converted into a yarn with 68 threads, which had a three-lobed cross section, spun on a standard spinning machine at a spinning speed of 325.5 m / min, with a throughput of 15.9 kg / hour. was obtained. Both the thread course in the chimney and the structure the thread wrap were good. The spinning temperature was 274 ° C. and the spinneret plate temperature was within the range of 274 to 279 C, which is about 15 C lower than the temperature required for unnucleated polymer is used.

Stretching bulging

The yarn was drawn-bulked as in Example 5, and the processing behavior made no difference. Trouble.

Details of the process and the yarn properties are given in Table 3.

Making a carpet

The yarn was nucleated "along a mil" Comparison Yarn processed in standard tufted carpets with a standard irbstoff ^r were dyed as in Example 5. FIG. The carpet made from the nucleated garr had a more uniform crimp and tuft structure and colored uniformly than the carpet made from the comparative yarn Satisfactory spinning temperature below that which is normally considered to be the minimum temperature in order to achieve useful product quality.

Table 3

Spinning speed mm ^; n

CaF ₂ . Weight percent

Average particle size of CaF, (; j.) Average distance between the particles of the

CaF, (μ)

O ₁ -O ₁ ,

DAT freezing point. C.

Spinning temperature. C.

Relative viscosity of the polymer

example j ^X 308 325.5 comparison ή 0! "P 0.2 308 0.03 0.03 217 (Λ C \ C 0.39 0.33 - 0.03 0.29 0.29 - 0.51 235 235 0.24 290 274 0.01 236 46 40 223 290 290 46 45

1806

Example 9
Production of nucleated polymer

A number of polyhexamethylene adipamide polymers have been made that contain calcium fluoride in variable form Concentrations from 0.003 to 0.25%. based on the polymer. In all cases These polymers were obtained by injecting a suitable amount of a calcium fluoride slurry (average Particle size 0.03 μ) in the evaporator part of a continuous polymerization spiral 4.1 kg / hour made at the 60% injection point.

Spinning process

IS

The calcium fluoride-containing polymer emerged from the spiral at a spinning speed of 119P in each case. m / min into 10-ply yarns • xtruded. The polymer had a relative viscosity of 33 and contained 0.3% TiO _{2 in} addition to the calcium fluoride.

Draw twist process

25th

The nylon yarns were in each case at a drawing speed of 1000 m / min Stretched titer of 30 denier stretched. The stretching ratios used were set in such a way that «Let the drawn yarns have an elongation at break of 30%. Process details and yarn characteristics are given in Table 4.

Continuous titer grading
and strip classification

35

The nylon 6.6. 30 denier yarns prepared containing various amounts of CaF were applied to the continuous titer uniformity and tested for stripe grading as described below. the Results are included in Table 4 below along with those for a comparative sample.

Continuous titer classification (C. T. E.)

This is shown as the greatest deviation in titre within 7.6 m of a 182.9 m long test piece of the stretched yarn using a konliiuiiei borrowed titer testers determined.

Stripe classification (D. S. Fi.I

5s

This is determined by knitting a flat piece of the yarn and then grading it according to arbitrary standards after dyeing in the blue Karhstoff CI 34 140. The same pieces were given a stripe rating of 1.2 or 3 ^ ⁰ in order of the intensity of the visible stripes, v.o'nci a rating of 3 showed a high stripe ink-i'.äi.

With a nucleating agent particle distance of less than 1 µ was shown by the yarn with a CaF, content noticeably better values for the continuous titre deviation and the stripe classification than that unnucleated yarn.

Example 10

Example 9 was repeated, with the difference that calcium fluoride with an average particle size of 0.11 μ was used at concentrations of 1 and 2% in the polymer. The numbers for this example are given in Table A.

Calcium fluoride slurry with an average calcium fluoride particle size of 0.11 μ was made as follows:

(a) 382 g of potassium fluoride were demineralized in 6.3 liters dissolved water.

(b) 527 g of calcium acetate were dissolved in 6.4 liters of demineralized water.

(c) Solutions (a) and (b) are boiled.

(d) Solutions (a) and (b) are mixed quickly

(e) The resulting suspension is boiled for 4 hours and allowed to settle.

(f) It is decanted, further demineralized water is added, and the suspension is allowed to settle again and the supernatant liquid is poured off.

(g) It is diluted with demineralized water to a 1.2% dispersion of CaF _2.

(h) The suspension is injected into the spiral at the 60% injection point at a rate of 1.1 l / hour. or 2.2 1 / hour injected. whereby a concentration of 0.5 or 1% CaF ₂ im (lain is achieved.

Example 11

Example 9 was repeated again, with the difference that calcium fluoride with a through Use an average particle size of 0.20 μ with concentrations of 1 and 2% in the polymer became. The test numbers for this example are given in Table 4.

Calcium fluoride slurry with an average calcium fluoride particle size of 0.20 ■>. was made as follows:

(a) 1898 g calcium acetate were demineralized in 8 l Dissolved in water.

(b) 2412 g of potassium fluoride were dissolved in 3 liters of mineralized water.

(c) Both solutions were filtered.

(d) 100 liters of demineralized water were heated to 100 C in a large container, and

(e) the calcium acetate solution was added while heating to 100 ° C.

lf | The potassium fluoride solution was increased to 90 (!

Ig) The hot potassium fluoride solution was while ·.! 1 minute with gentle mixing to (given el.

(hl The resulting suspension was heated to 100 ° C. for 30 minutes and stirred.

(i) It was allowed to cool to room temperature overnight.

(j | The supernatant: liquid was decanted, and the suspension was demineralisicrieni Water again diluted and again allowed to settle and decanted.

(1 <| The CaF- was again dispersed to produce a 2.5% suspension. To add the CaK to keep in suspension it was necessary to stir.

II) The suspension was injected into the column at a rate of 1.1 or 12 hours for 1 hour. a concentration of 1 or 2% CaF ₂ in the polymer was obtained.

18 06

table

example ",. CaF,
in the polymer Medium
CaFV particle
distances 1 12 DTA
EP o, - o " Stretching ratio
Door a week
Elongation at break Pmduklivitfns-
ratio CTE. .- DSE. in; i C. 9 (a) 0.003 1.4 TTT 0.7 2.8 6.9 3 9 (b) 0.006 1.1 223 0.12 3.4 2.0 1.7 9 ic) 0.012 0.86 227 0.21 3.6 1.0 9 (d) 0.025 0.69 234 0.29 3.8 1.0 9 (e) 0.055 0.52 234 0.31 3.8 1.0 9 (0 0.072 0.48 235 0.44 4.1 1.0 9 (g) 0.086 0.45 237 0.42 4.0 1.0 9 (h) 0.222 0.31 236 0.44 4.1 , 6 1.0 9 (i) 0.521 0.24 238 0.48 4.3 , 6 1.0 10 (a) 1 0.74 233 0.23 3.30 , 5 - OK (b) T 0.59 234 0.29 3.41 T - 11 (a) 1 1.4 234 0.12 3.23 , 7 - 11 | b) T 1.1 234 0.18 2.24 1.4 - comparison - 0.08 2.85 1.5 B e i s ρ i e , 0 - , 19th - , 27 - .33 - .33 3.8 .44 , 40 .44 .51 .16 .19 .13 , 14 .0 Draw ratio for a 3% igc
D PiRrlnliiiiiniT

In this example the CaF _{2 was} precipitated in situ using the following method: 5240 g of nylon 6,6 salt was mixed with 2706 ml of lime water. which contained 1.67 g / l calcium hydroxide, and a solution of ammonium fluoride (NH ₄ F). containing 4.52 g of NH ₄ F in 22 ml of demineralized water and 6 g of acetic acid was added. The resulting mixture was placed in an autoclave with a capacity of 13.6 liters and polymerized in the usual manner.

The polymer was spun at a spinning speed of 1198 m / min and on a titer of 40 denigrated. Process clarity and yarn properties are given in Table 5.

Table 5

45

CaF ₂ (%).

0.09

O, O _n 0.48

DTA freezing point. C 239

Productivity ratio 1.40

Example 13

This example illustrates the use of a static copolymer of nylon-6,6 and nylon-6.

A mixed polymer of nylon-6,6 and nylon-6 in a weight ratio of 95: 5 with a content of 0.1% CaF ₂ (average particle size in the pulp 0.03 μ) and obtained by chip coating the polymer, was spun and drawn in monofilaments with a titre of 20 den at an average spinning speed of 305 to 685 m / min. Process details and yarn properties are given in Table 6.

table

Spinning speed m / min

Average particle size of CaF ₂ in a ..,
Draw ratio for a 30% elongation at break

O ₁ -O _n

DTA solidification point C.

305 610 0.43 0.43 4.7 4.5 0.23 0.35 223 225

685 326 0.43 4.5 4.75 0.42 - 222 217

Examples 14-18

Nylon-6,6 with a relative viscosity of 40 and an Oehult of 0.2% TiO ₂ , which was micronized at various concentrations by means of £ aF ₂ , which had an average particle size of 0.03 μ, was produced at a rate of 230 m / min spun into a yarn in which each thread had a linear density of 150 den. These conditions are for the practical purposes of boundary spinning conditions. Details are given in Table 7.

17th ■ '"CaK, the thread
Igespnnnenl 1 694476 DTA o, - ο, Ii) 18th Particle Nothing 150 EP.
C. 0.01 [U distance 0.0026 150 Table 7 222 -0.02 Solidification - 0.0052 150 TTT 0 Yerstreck ^ ratio punkl'l in the fireplace
cm 1.5 example 0.010 150 223 + 0.17 IUr .! (! "Urn
Kiss stretching 120 1.2 comparison 0.050 150 231 + 0.25 4.68 90 0.92 14th 0.10 150 234 + 0.25 4.44 80 0.54 15th 235 4.30 - 0.43 16 4.65 60 17th 4.66 60 18th 4.59

• | In the chimney, cm below the spinneret plate.

These results show that, among these boundary spinning threads, a yarn with O, - O ₀ > 0.2 with a maximum nucleating agent particle distance of less than? 1 µ is obtained; this agrees well with the preferred conditions for nucleation under normal spinning conditions.

Although with nucleating agent particle spacing greater than 1μ, the full benefits of the Invention are not obtained, there is still a useful effect, namely because the solidification point in the spinning chimney is raised and thus higher Spinning speeds can be applied.

Example 19

classified. The temperature of melting and quenching for the various polyamides used in These tests have been used are as follows; specified.

To determine whether other inorganic additives in polyamides have an effect as nucleating agents result, d. H. result in undrawn threads with the above-mentioned X-ray orientation parameters, readout tests were carried out as follows:

Water-insoluble inorganic additives were dispersed at 290 ⁰ C under nitrogen in a glass tube in the polymer, the glass tube was equipped with a stainless steel stirrer • piralenförmigen. Water soluble compounds were added to the polyamine salt prior to polymerization.

The additives became thinner by determination of the DTA congealing point and by melting Sections of the polymer in silicone oil for 30 minutes, subsequent quenching in Siliconö! during 15 minutes and cooling to room temperature polymer

Sehmel / -I temperature

Starting temperature

Polyhexamethylene adipamide

(Nylon-6.6) 300 245

Polyoctamethylene adipamide

(Nylon-8,6) ^! 280 225

Polydecamethylene adipamide i

(Nylon-10.6)! 270 210

Poly- (3,3'-p-phenylene-bis-j

propyl-adipamide) \

(Nylon-3.P.3,6) j 260 205

The sections were examined under a polymerization microscope to determine the size of the spherulite to determine. Effective nucleation is indicated by a noticeable increase, i.e. H. 10 C or more of the DTA freezing point, although a smaller increase in the DTA freezing point in Combination with maximum spherulite sizes of 20 μ or less also results in effective nucleation Show. The results of the readout test are given in Table 8 below.

polymer (• .in / clheitcii the /uv.t/e Ta at ic 8 - - - N - noticeable ent
opaque
Nucleus - - ■ - - - Nukicicrungstesl ation Nylon-6,6 N description source Level, that is Nucleus the / tisal /
in Polvmer
dispersed maximum
Spherulite size ation Calcium Calcium approximate
Particle size would UTA- N - ■: easy to Nylon-6,6 fluoride acetate + finished 4th Freezing
Point N Potassium- I to 20 polymer "C fluoride 233 talc trade (3 MgO usual finished 20th 4SiO ₂ product 4 to 30 polymer H ₂ O) 223

continuation

It

Individual healing Jer additives approximate
Partial greetings Level at which Succession tests DTA- N = noticeable the addition
in the polymer
dispensed Solidification
Point Nucleus
ation description source 0.5 to 6 would tTuixirnale
Spherulite size C. N = easy to polymer finished 230 ent
opaque
Nucleic talc trade polymer 15th ation Nylon-6,6 usual -N Product, With. one flowable gen Me dium ground 220 Comparison 1 to 100 60 Nylon-6,6 sample 6.6 salt 230 A.galit 3.x trade 15th Nylon-6,6 (Calcium usual N. magnetic product sium- silicate, 59% SiO ,, 28% MeO. 5% CaO 6.6 salt 229 microni- trade 20th Nylon-6,6 more usual N Asbestos product (a CaI- cium- Magnetic sium- 1 to 2 Silicate) finished 231 Antimony- trade Polymei 20th Nylon-6,6 trioxide usual N (Senar product 1 to 30 monit) finished 228 Molybdenum- trade polymer 20th Nylon-6,6 disulfide usual I to 40 N product finished 229 graphite trade polymer 15th Nylon-6,6 usual 1 to 10 N product finished 223 Lead wolf Blciacctate polymer 15th Nylon-6.6 ramat + Sodium 1 to 20 N wolframate finished 224 CaF ₂ Calcium polymer 20th Nylon-8,6 acetate N + Potassium - fluoride I to 20 - 206 Comparison
sample
CaF ₂ - finished 30th 204 Nylon-8,6 Calcium polymer 15th - Nylon-10.6 acetate N + Potassium - Comparison
sample
CaF ₂ fluoride 1 to 20 - 200 - 3 P 3,6 salt 60 190 Nylon-10.6 Calcium 10 - Nylon-3P3, acetate N + Potassium fluoride

I 694476

continuation

Individual healing of additives approximate
Particle size Level at which Nucleation test DTA- N = noticeable the addition
in the polymer
dispersed Solidification
Point Nucleic description source would maximum
Spherulite size C. N = easy to polymer 179 ent
opaque
Nucleic Comparative 0.5 to 6 40 ation Nylon 3P3.6 test finished 225 Barium- barium polymer 15th Nylon-6,6 fluosilicate chloride N + Fluo- silica. with the energy one flow capable Medium c grind

The above results show that many inorganic Additives can be used to prepare the polymer of the invention provided that they are used in the correct particle size (less than 0.5 μ).

Claims (4)

30 claims: 1.Thread made of polyhexamethylene adipamide or another polyamide with a linear crystallization rate of the same order of magnitude, which contains a nucleating agent and optionally a matting agent, and in the undrawn state has a molecular orientation which gives an X-ray reflection diagram, in which O ₁ O _{1 is} greater than 0.2. characterized in that the nucleating agent is inorganic in nature and has an average particle size of less ais 0.5 μ and is present in a concentration Jass the maximum Nukleierungsmittelteilchenabstand by the expression xc G (T) ul üceebcn is. G is the linear crystallization rate in ■ j. see is at temperature TC.
S is the maximum distance between nucleating agents, XC is the distance from the solidification point to the spinneret for an unnucleated polyamide when it is melt-spun into filaments, and t is the time in seconds it takes for a point on the thread to travel from the spinneret to a point X , where X is any point between XC and the spinneret. 2. Polyamide thread according to claim 1, characterized in that it is at least 0.03 percent by weight Contains matting agents. 3. Polyamide thread according to claim I or 2, characterized in that it is used as a nucleation center! Contains calcium fluoride. 4. Polyamide thread according to Claim 3, characterized in that it is made of polyhexamethylene adipamide and calcium fluoride with an average particle diameter of 0.03 μ at a concentration of not more than 0.008 percent by weight.