JPS58203112A - Production of polyester fiber - Google Patents

Abstract

PURPOSE:A polymer mainly consisting of ethylene terephthalate units is subjected to melt spinning, the filament is heated in a chimney right beneath the spinneret at a specific temperature, then cooled, taken up at a high speed and drawn to produce the titled fiber with a specific optical birefringence and density without filament breakages. CONSTITUTION:A polymer that is composed of more than 90mol% of ethylene terephthalate unit as recurring units in molecular chains and 0.80-1.30 in its intrinsic viscosity, when it passes through the spinneret, is subjected to melt spinning through the spinneret. A heating chimney 12 of 5-25cm height is set immediately beneath the spinneret 11 to keep the atmosphere in the space from the rearsurface of the spinneret to 5-30cm below at a temperature of the polymer melting point to 400 deg.C and arrange the temperature so as to lower downward and the extruded yarn is passed through the chimney. Then, the yarn is cooled in the cooling chimney 15 by blowing air and taken up by means of the taking-up roller 21 that is driven at a peripheral speed of 1,500- 3,000m/min to give the undrawn yarn satisfying formulas I (rho is density), formula II(A is the formula III) and formula IV (DELTAn is optical birefringence). Without being wound up, the resultant undrawn yarn is heat drawn at a ratio of 1.5-3.0 and wound up to give the objective yarn.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing polyester, particularly polyethylene terephthalate.

Polyethylene terephthalate or B tire cord 11I
It is well known that i-zukyou Q, but in recent years, dimension stability and 11
As a manufacturing method of u1 durable polyethylene terephthalate tire cord material <W yarn), JP-A-55-5
The method of Publication No. 8052g was proposed.

This method is a relatively excellent method in which the polyethylene terephthalate spun yarn is still drawn under tension to obtain an undrawn yarn with relatively low 4i corrosion, and then stretched and heat treated.

However, in this method, the spun yarn is rapidly cooled directly under the spinneret, so if you want to obtain a spun yarn with a large number of filaments and a large fineness using 4IV polymer, single yarn breakage is likely to occur, and homogeneous spinning There was a problem that yarn could be obtained and it was warm. Especially the east line? When the above method was tried for the so-called ljf plate spinning and drawing method, the occurrence of yarn breakage was lI#.

Therefore, the present inventors increased the number of single yarns of the spun yarn, for example, increased the needle depth to 500 denier or more (and used the above-mentioned well-known method for straight twist spinning). As a result of intense research aimed at establishing an industrial manufacturing method for polyester/L/w and textiles, which have a small number of bald people, the fact that the handprint of lack is adopted is good, that is, there is no invention. 9) Retrospectively melting a polymer in which 90 mol% or more of the d-return structural units of the molecular compound are ethylene terephthal units.
Spinning and obtaining spun yarn (However, when going back to the monthly IJ spinneret @'118c! Bolimaha α80~.1.5
(b) Attach a heating cylinder of 5 to 25c11 directly below the spinneret to create an atmosphere of at least 51 or more and at most 501 or less from the bottom surface of the spinneret, Melting point of the polymer ~
In an atmosphere where the temperature is 400°C and the temperature is lower as the temperature goes down) (- passing the spun yarn as described separately), (c) blowing cold air on one spun yarn that has passed through the atmosphere to make it meditate. cooling the spun yarn at 1500-3000 m/mi
, taken up by a take-up roll at LfO Renka, the following equations (1), (2), and (3J) are simultaneously satisfied. To obtain an undrawn yarn, 1.558<Δn(1,565(1) 1,005 A≧ρ≧α995 A (2) However, in formula 2), A is 10”x(4,4(Δn)2+1167( △n))+1
．． It is 551.

25X10-”≦△n≦60X10”, (3)
) The undrawn yarn taken off at CI-/
A method consisting of simply winding (sequentially hot stretching 1.5 to 50 times and then winding) is adopted.

The non-explosion method is clearly different from the method described in Japanese Patent Publication No. 575-1567 due to the birefringence of the undrawn yarn and the take-up speed, and the physical properties of the obtained polyester fiber 1.
There is also a clear difference in this regard, with the product obtained by the method of the present invention having significantly better dimensional stability and durability.

The method of the present invention will be specifically described below with reference to the drawings.

Note that FIG. 1 is a process diagram in which an embodiment of the method of the present invention is applied, and FIG. 2 is an enlarged longitudinal #R view of a portion of the present invention that creates a specific atmosphere.

In the polyester fiber of the present invention, 90 mol% or more, preferably 95 mol% or more of the repeating structural units in the molecular chain are polyethylene terephthalate units.

Obtained from polyester. In addition to terephthalic acid, ethylene glycol, and ethylene oxide components, such polyesters include aromatic dicarboxylic acids such as isophthalic acid, phthalic acid, naphthalene cafflebonic acid, and diphenyldicarboxylic acid, and diol components such as propylene glycol and butylene glycol. There are copolymerized polymers, mixed polymers in which the latter component, or a polymer obtained from the former component and the latter component are dissolved and mixed in polyethylene terephthalate.

The above polymer is melted at the spinneret QO and passed through the spinneret (11).
It is bent and extruded, that is, melt-spun to become a spun yarn (Y).

In the present invention, the polymer is selected and the melting conditions are selected so that the intrinsic viscosity of the polymer when passing through the spinneret (11) is α8o to 1.30.

When the intrinsic viscosity is lower than α80, it is 7.5 g as intended by the present invention.
/e1 or higher strength and durability, especially yarn with improved mechanical fatigue resistance, cannot be obtained. If the inverse t is larger than 1.50, yarn breakage occurs frequently during the high-speed direct spinning and drawing of the present invention, making stable yarn production difficult.

In order to set the intrinsic viscosity within the above range, the intrinsic viscosity of the polymer to be melted must be slightly higher than the above intrinsic viscosity (L8
Choose one between 5 and 1.50.

Note that the intrinsic viscosity in the present invention is measured and calculated by the following method.

Orthochloropheno-7+ using an Ostwald viscometer
/25 mjJt On the other hand, the relative viscosity ηr of a solution in which 2 g of the sample was dissolved was measured at 25° C., and the force V was calculated using the following approximate formula.

1,・□・1 Engineering■=α口242η,+12654 t=Number of seconds for solution to fall (seconds to=Number of seconds for orthochlorophenol to fall<e>d-Density of solution (g/C11,) liO-Ortho Chlorophenol density & (g/CC
) Next 1 In the present invention, the force p boxy μ end group of the polymer is 256q/10'g, preferably 15@qL/1
(1'g or less. To achieve this, it is necessary to obtain a polymer with fewer carboxyl end groups in a previous process, that is, a polymerization process that is a polyester production process, or to recycle the polymer in a melt-spinning process. An end-capping agent is added in the bath-spinning step tcp4, which reacts with the polymer during melting to reduce the number of carboxyl end groups.

These two methods in the present invention are based on well-known methods.

The spinneret (11) has a spinneret hole (<11A) on the circumference having a constant radius (preferably 1/2 or more of the outer diameter of the spinneret) from the center (C) and ρ. It has a structure in which 1 to 4 rows of similar cap holes (11B) are arranged on the outside.
In Fig. 2, one row of cap holes is shown on the outside.

Directly below the spinneret 00 is a heating cylinder (6
) is installed, and the atmosphere inside is heated within the temperature range of the melting point of the polymer, usually from 260°C to 400°C, preferably from 280 to 360°C, and furthermore, the culm is heated to a lower temperature in the downward direction. has been done. However, such a temperature gradient is not only positively applied, but also by energizing a heating source built into the heating cylinder α2, such as the heater θ◆, so that it exhibits the same temperature, and creating a temperature gradient inside the cooling cylinder described below. The lower temperature may be lowered by the presence of cold air. In short, the atmosphere between 51 and above and 301 and below on the bottom surface of the cap is 0.
3, it is sufficient that there is no region showing the highest temperature in the middle from the top to the bottom.

Further, the temperature in the atmosphere 03 must not be such that it satisfies the above two conditions at the same time, and must not be heated too much so that the birefringence of the undrawn yarn falls outside the range shown below. The degree of heating, especially the temperature height at each location and the length of the heating atmosphere, must be set within a certain range. The temperature height is determined in consideration of the relationship between birefringence and density, which will be described later.

The length of the heating atmosphere is 5 minutes starting from the bottom surface (11') of the cap.
(1 m or more and 301 or less, preferably 251 or less,
The length of the surface to the lower position is L).

When the spun yarn passes through the atmosphere described in L, even if the spun yarn has a large number of filaments and a large fineness, the number of yarn breakages of the spun yarn (Y) that passes through the cooling cylinder described later is reduced. The reason for this is that although the polyethylene terephthalate melt that has reached the spinneret 00 strictly has a slight difference in thermal history, the spun yarn (Y) that has passed through the atmosphere 03 does not improve its orientation there. This is because it evens out the quality.

Therefore, the occurrence of thread breakage is reduced.

Next, the spun yarn (Y) that has passed through the atmosphere Q3 is
It is cooled by the cold air a.

Preferably, the cooling cylinder αQ has a structure in which through-holes are bored in the inner circumferential wall of the cooling cylinder αQ, and multiple circularly arranged spindles, ?
Cold wind α is blown from the outer periphery of 1(Y). The cold air that has come into contact with the spun yarn (Y) gathers at the center (C) and descends through the chimney duct H, which is connected to the lower part of the cooling cylinder a0. The cooled spun yarn (Y) passes through a chimney duct, is further cooled, and comes into contact with an oil feeder, where an oil agent is applied. After the spun yarn (Y) to which the oil agent has been applied is focused by a guide (not shown), the surface speed is 1500.
~5000 m/min preferably 1750~2500
It is taken up by a take-up roll (21) that rotates at m/min.

If the take-up speed is less than 1500 m/min, even if the fibers are passed through the heating and cooling zones after spinning specified in the method of the present invention, the fibers obtained through the drawing process will not have the high modulus, low shrinkage, and Not satisfied with durability. Collection speed is 15
In the case of adopting the condition of immediately quenching the yarn directly under the spinneret even for 00 m7 minutes, for example, the heating zone directly under the spinneret should be set to 51, and the single yarn fineness of the yarn could be set to fine (the single yarn fineness after drawing would be fine). If the density is 2 denier M or less, satisfactory properties may be obtained in some cases, but in this case, the spinning and drawing properties are significantly compromised.
, it is impossible to adopt it industrially.

On the other hand, if the take-up speed exceeds 5000 m7 minutes, the strength of the lij fiber after direct spinning and drawing becomes low, for example, 75 g/α
The above is undesirable because it is difficult to produce yarn and yarn breakage occurs frequently during stretching, making stable yarn spinning difficult.

If the undrawn polyethylene terephthalate yarn is directly spun and drawn under the conditions described above, the yarn intended by the present invention can be obtained. To obtain this, it is necessary to organically combine the above conditions. In particular, it is necessary to link and combine conditions such as the length and temperature of the atmosphere inside the heating cylinder, the size of the cooling cylinder, the speed of cold air, the viscosity of the polymer, the spinning temperature, and the speed at which the amount of discharge from the spinneret is taken up. be. However, in actual operation, these conditions are complex, and it is difficult to understand the relationship between them, but in the present invention, even if one condition is changed, it is still possible to To determine the physical properties of the obtained yarn, the density of the undrawn yarn should be adjusted to match the birefringence (△n) of the undrawn yarn after transportation. It turns out that by rubbing L(rho) once so that it is within a certain range t, it is possible to change the conditions of the 1.I period. 60X10
"Preferably 60X10-3 to 50X10" and density (ρ) of 1.558 to 1.565, preferably 1.5
Within the range of 40 to 1.555, and 1.005
A≧ρ≧(Rub 1 so that it is in the range of L995A. In addition, in the above t, A is 1o "X (t4 (△n)" + 1
147(8n))+1.551. By doing this 1, it becomes easier to manage complicated spinning conditions, and even if it is directly spun and drawn in the subsequent process, it is possible to stably produce raw yarn with specific physical properties with less yarn breakage. It is possible to obtain.

Note that the birefringence (Δn) and density are values obtained by tail measurement using the following method.

Birefringence (△t1): = Kon Co., Ltd. gX'FP-11ff
The measurement was carried out by the usual Beretskuhn-Penseta method using l polarized light mmm and sodium Lang Dm as a light source.

Density: Measured at 25°C using a density gradient tube prepared using carbon tetrachloride as a heavy liquid and n-hebutane as a light liquid.

The undrawn yarn taken off at the next take-off row /L/(21) is fed to the supply roll (22) at a drawing ratio of less than 1.10 times, preferably from 1.005 to 1.05 times, preferably First stretching roll A/ (25), second stretching roll (24)
and 10.5 to 50 times the relaxation roll (25),
Preferably the first stage stretching ratio is 1.5 to 1.9, preferably t
The film is stretched at a stretching ratio of 3 to 1.7 times, and a second stage stretching ratio of 1.2 to 1.6 times, preferably 1.5 to 1.5 times. Second stretching roll (2
Q, 90 to 1.
05, preferably Q, stretched (correctly, slightly relaxed) at 95 to 1.00 times. And the final total stretching ratio is 1.5
It is said to be ~50 times more.

The drawing temperature for the take-up roll (21) is 150°C or lower, preferably 120°C or lower, and the supply roll tv (22) is 60°C or lower.
-150°C, preferably 80-150°C, the first stretching roll (25) is 80-180°C, preferably (100-16
0℃, and the second stretching roll (the second one is 180-260℃
, preferably from 2IJO to 250°C, and the temperature of the rolls in later steps is determined to be at or at least the same temperature as the cylinder. The temperature of the relaxation roll (25) is room temperature ~
The temperature should be in the range of 240°C.

The stretched drawn yarn is 5500 to 600 in the winder (26).
0 m/min speed, preferably 4000-550
Q m/min 17) It is wound 4 times and becomes a raw yarn.

The yarn obtained by the above method has the following characteristics.

(a) Dry heat shrinkage rate 8≧ΔS≧296 (b) Initial tensile resistance 150≧M, t≧90 g/(1ki
Strength 1cLO≧T/D≧7.5 g/d) Elongation 15.0≧E≧jO% -) Birefringence 190x10″≧△n≧160xlO-”The above characteristics obtained in this study...Growth The raw yarn to be used is twisted by a known method, for example, with a twist coefficient of 2,100 to 2,500, and the adhesive is applied by heat treatment at 240 to 250°C and a net stretch of -2, [l to 5.0%. When converted into a processing code, it has the following characteristics. Compared to conventional processing codes, the "intermediate elongation yield" value is significantly lower. This means that even if a cord with a low intermediate elongation is made by increasing the modulus, the dry heat shrinkage rate can be lower than that of a conventionally treated cord.

(To) Strength To 8 and T/D Shi 55 (G) Intermediate elongation zo2Mg;, = x.

(4.5kg!iii Elongation at force n(t) Dry heat retention rate 5.0280zl: 1-0%(su) Intermediate elongation 10 Dry heat retention rate 9% - ME+88 7% Tires using the above-mentioned treatment needles also have excellent running durability.Model 1 has excellent mechanical properties due to the Goodyear Mallory-Thug (GY) fatigue test and the Goodyear Isk fatigue test. This can be understood from the results that it has fatigue resistance and is superior in chemical deterioration resistance as shown by the strength retention rate after treatment at high temperature by embedding treated cord in rubber.

When the fiber of the present invention is used as a tire coater, it takes advantage of its excellent characteristics of dimensional stability and durability, and exhibits useful performance when applied to a special radial tire. This is because dimensional stability is maintained even if the treated cord is designed to have a high modulus.

On the other hand, by designing the modulus to be relatively low and taking advantage of its excellent durability, good performance can be obtained even when using bias tires.

It is also useful not only for tire cords, but also for applications requiring dimensional stability, durability, especially bending fatigue resistance, and heat resistance, such as rubber reinforcing fibers for belts, conveyor belts, and the like.

Hereinafter, Example 1 and the present investigation will be described in detail.

Example 1 Engineering vi, 20, carboxyl end group once 15 eq/10
The fibers were spun using a polyethylene terephthalate chip extruder type spinning machine at a spinning temperature of 295°C. The spinneret has a hole diameter of I16mm, a number of holes of 192, and a discharge rate of 58'.
Og/min.

Directly below the mouthpiece was a heating region consisting of a 5 Q+e thin spin block, and a heating cylinder with a length of 70 mm and a diameter of 220 m was attached directly below that region, that is, at the bottom of the spin block. When the heating tube was controlled to have an ambient temperature of 350°C at the 55th point in the center of its length, the ambient temperature in the region t directly below the cap and 1001g below the cap surface was 5.
The temperature was maintained between 00°C and 550°C. The material was rapidly cooled by passing through an annular chimney having a length of 500 m and an inner diameter of 220 mm, which was attached directly below the heating cylinder via a heat insulating plate with a length of 10 mm and an inner diameter of 200 mm.

The chimney wind temperature was 25°C and the wind speed was 45 m/min.

The spun yarn was subsequently lubricated with an oil supply roller, then bundled with a guide and taken off with an unheated Nelson roller (IFR winding 5 times) rotating at a surface speed of 12,500 m/min.

Next, the yarn was stretched by 1.05 times with 21PR (6 times of winding) heated at 90°C without being wound, and then stretched by 1.05 times with IDR of 120°C (7 times of winding). 1.56 times between iDR and 2DR heated at 240℃
(10 windings), 1.35 times 2DR and non-heated RR (296 relaxation between 4 windings), and then winding with a winder.As sample f1, the spinning conditions were Table 1 shows the properties of the IFR drawn yarn and the properties of the drawn yarn in Table 2.

For comparison, the characteristics of fibers spun and drawn in the same manner with different heating cylinder lengths and heating cylinder temperatures are also shown.

The characteristics of the IPR drawn yarn change by changing the spinning conditions, but the spinning discharge amount and drawing ratio are changed according to the characteristics of the drawn yarn.
It was set to 1596.

The drawn yarn obtained by the above method is twisted by 4?
Two yarns were twisted together at T/10cm to make a raw cord.

Next, this raw code was converted into resorcinol-formal fiber Ttsu;L and
Kosha (UK) wV! The adhesive made from the "Pexul" mixture was heated in a heating furnace at 160℃ for 60 minutes at a fixed length.
Pass for drying for seconds, then continue (L5-496 19
The cord was passed through a heating furnace at 250° C. for 70 seconds while giving 1% relaxation, and then heat treated at 240° C. for 70 seconds while giving 1% relaxation to obtain a treated cord. Table 2 also shows the processing code characteristics.

It can be seen that the cords 1 and 4 obtained by the method 1 of the present invention have good reeling properties, the treated cords have a high modulus, that is, they have a low yield even with a low intermediate elongation, and they have excellent fatigue resistance.

Example 2 111.25. Carboxy end group concentration 25 eq/10
'g polyethylene terephthalate chips were spun in the same manner as in Example 1. However, in order to reduce the concentration of carboxyl end groups in the filament, immediately before melting the fiber, ortho, phenylene, phenyl, glycidyl ether/L/(
Spinning was carried out while adding 15% by weight of OPPG). The spinneret used had a hole diameter of Q, a diameter of 6 mm, and a number of holes of 288. The spinning and drawing conditions (Table M5) were examined so that the fineness structure after drawing was 1000 denier 1v-288 filament and the residual elongation of the drawn yarn was about 12 to 15%. Table 4 shows the properties of the drawn yarn and treated cord.
I showed this. Note that conditions not specified in Table 5 are the same as in Example 1.

Sample cliff 16 showed the result of spinning with 500 denier-288 filament yarn.

It can be seen that within the range of the method regulated by the present invention 1, the yarn reeling properties are good and the properties are also excellent.

[Brief explanation of the drawing]

FIG. 1 shows a process diagram of the present invention. Figure 2 is an enlarged view of the summer portion of Figure 1. 11... Spinneret 12... Heating tube 1
5... Atmosphere 15... Cooling cylinder 19
...Chimney duct 20...-Oil supply roll 21...Take-up row/l/22...Supply roll 25...First stretching row) v 24-@1.
Second Stretching Roll Patent Applicant Toshi Co., Ltd. Figure 1 Procedures Amendment Book Show f057 Can? Kazuo Wakasugi, Commissioner of the Japan Patent Office, January 1, Indication of the case, Patent Application No. 84895 of 1984, Title of the invention, Process for producing polyene teμ fiber Spontaneous 5 Number of inventions increased by amendment 0 6 Subject of amendment (1) As shown in the appendix in the “Claims” section of the specification. (2) Specification page 5, line 5 and page 15, line 10~
Line 11 "10-'x(4,4(△n)+(1167(△n)
')-z,551'' to [4,4(hen)''+[L167(△n) + 1.
Correct it to 5514. (3) On page 17, line 9, ``Good'' is corrected to ``Good''. (4) In Table 2 on page 25 of the same document, the text ``'' has been amended to ``''. (Attachment) Claims (a) Melt-spinning a polymer in which 907 μ% or more of the repeating structural units of molecules are ethylene terephthalate units through a spinneret to obtain a spun yarn (provided that (b) A heating cylinder of 5 to 25 α is attached directly below the spinneret, and the polymer has an intrinsic viscosity of 1180 to 1.50 when passed through the spinning nozzle, so that the polymer has an intrinsic viscosity of 1180 to 1.50. , a maximum of 50 cM or less, the melting point of the polymer ~ 40 cM
Passing the spun yarn through an atmosphere with a temperature of 0'C and a lower temperature as it goes downward; (c) Cooling the spun yarn by blowing cold air onto the spun yarn that has passed through the atmosphere. , Kano) cooled spun yarn at 1500-5000 m/min
Pick up with a pick-up row μ that rotates at a surface speed of
To obtain an undrawn yarn having birefringence (Δn) and density (ρ) within a range that simultaneously satisfies formulas (2) and (3), 1.! 558<ρ<t 565 (1)1,
005 A≧ρ≧α995 A (2). 25 X I F"≦△n<60X10" (3) (E)
After the undrawn yarn taken off by a take-up roll is subsequently hot-stretched to 1.5 to 3.0 times without being wound up,
A method for producing polyester fiber, comprising: winding.

Claims (1)

[Scope of Claims] (a) Bath-spinning alcoholimer in which 90 moyvN or more of the repeating structural units of the molecular chain are ethylene terephthalate units through a spinneret to obtain a spun yarn (provided that When the self-σi polymer is 1α80~1.5
A heating cylinder of 5 to 251 is attached directly below the spinneret, and at least 51 or more, and a maximum of 5
The atmosphere between 01 and below is +1 and the melting point of the polymer ~ 40
#1 in the surrounding air where the temperature is 0℃ and the temperature is about 10,000 degrees lower
To surpass the origin of this @U story, (c) ll'll iil:! Cooling the spun yarn by blowing cold air on the spun yarn passing through the atmosphere, 2) Cooling the spun yarn at a speed of 1500 to 3000 m/min.
Pick up with a pick-up roll that rotates at a surface speed of (1) below.
To obtain an undrawn yarn having birefringence (Δn) and density (ρ) within a range that simultaneously satisfies formulas (2) and (3), 1.558<ρ<t 565 (1)
1,005 A≧P≧a tp 9 s A
(2) Since it is l, A is 10-”X[4,4(Δn)”
10(L167(Δn)) + 1.551. 25X101≦Δn(60x1G-” (3)(
e) The unprocessed drawn yarn m taken up by a take-up roll is subsequently hot-stretched 1.5 to 50 times t without being wound up by -7, and then wound up; Method of manufacturing lv fibre.