JPS58115117A - Polyester yarn and its preparation - Google Patents

Abstract

PURPOSE:To obtain the titled yarns, having improved strength, dimensional stability and fatigue resistance, and useful for reinforcing rubber, etc., by melt spinning a polymer having a specific intrinsic viscosity at a specified spinning speed, heat-treating the resultant filaments just under a spinneret at a specific temperature for a specified time, hot-drawing the filaments after the oiling at a specific draw ratio, and heat-treating the drawn filamentary yarns at a specific temperature. CONSTITUTION:A molten polyester consisting substantially of polyethylene terephthalate having 0.65-1.15 intrinsic viscosity is extruded through a spinneret 1 having many holes at 1,500-4,000m/min spinning speed, heat-treated in a heating zone 2 provided just under the spinneret 1 under such conditions of the heating temperature and time as to make the relation between the spinning speed[X (m/min)]and the birefringence[Y (X10<-3>)]of the undrawn filaments satisfy formulaI(Y1 is formula II: Y2 is formula III; 1,500<=X<=4,000), oiled with an oiling roller 4, hot-drawn at >=80% maximal draw ratio by godet rolls 7-10 and heat-treated at 150-250 deg.C to give the aimed filamentary yarns having 160X 10<-3>-200X10<3> birefringence, >=25 yarn tenacity index, 10-25% elongation at break, etc.

Description

[Detailed description of the invention] The invention has high strength and excellent dimensional stability.

High-performance rubber reinforcement with fatigue resistance, especially suitable for carcass materials of radial tires for passenger cars.
Polyester multifilament) and its manufacturing method 4-Related.

Polyester yarn has excellent properties such as high strength and a higher initial modulus than nylon, so it is widely used as a rubber reinforcing cord for tire cords and the like. It is particularly suitable as a reinforcing cord for passenger car tires.

Conventional general-purpose polyester thread for rubber reinforcement was established in 1968.
- High tenacity type yarn obtained from high polymerization degree polyester as disclosed in Bulletin No. 7892 and Mochikin No. 1853-1367, and Japanese Patent Application Laid-open No. 53-58028 -:
- There are high initial density fiber staved yarns obtained from relatively low weight polyesters as shown. Cords using the former have high strength, but have poor dimensional stability and high work loss at high temperatures, resulting in extremely poor fatigue resistance.
It has the disadvantage of vh. In addition, although cords using the latter have excellent dimensional stability, they have low strength and
It also has the disadvantage of poor fatigue resistance.

In order to improve this drawback, Japanese Patent Application Laid-Open No. 53-58031, l'i! Publication No. 353-58032 C: proposed a polyester yarn and its manufacturing method with the aim of reducing work loss and improving fatigue resistance. The cord using this proposed polyester yarn has zero work loss.
．． 004 to 0.022 shows excellent fatigue resistance not found in conventional yarns with small scratches and scratches.

However, according to the studies conducted by the present inventors, the strength of the proposed polyester yarn during twisting was extremely large, and the strength after making it into a cord was low and could not be used for practical use (: rounding resistance).

That is, this proposed polyester yarn is
As described in the actual example in Publication No. 58031, the strength is at a relatively high level of 7.5 to 9.1 j'/d, but the elongation is extremely high at 6.7 to 8.1 j'/d. Because it is small, the strength of the yarn is low when twisted, and the strength of the cord obtained is 4.5
5.511/d, and there was a problem in that it did not have the strength practically required as a rubber reinforcing cord. Further 4
;, this method for producing polyester yarn is based on lθ~ right below the spinneret.
Due to the method characterized by rapid cooling in a gas atmosphere of 60'C, the spun yarn does not have a high drawing double curtain, which reduces productivity (I).
8 Thread speed x drawing ratio II) is low, and in order to achieve high strength, the thread is drawn to the point of breaking, so there are many thread breakages during drawing, making stable production difficult. It is clear that it is 4=.

Therefore, there is still a need for carcass materials for passenger car tires, especially C; radial tires, and polyester threads that provide a salt layer-like cord that has high strength, dimensional stability, and fatigue resistance, and that stabilize it. Moreover, a method for producing it with high productivity has not been obtained.

The object of the present invention is to provide a polyester yarn that provides a high-performance rubber reinforcing cord that has high strength, excellent dimensional stability, and fatigue resistance, and is particularly suitable for cords for carcass of radial tires for passenger cars, and to provide a cord that is stable and stable. 4. To provide a method for manufacturing with high productivity.

As a result of intensive research aimed at achieving such an objective, the present inventors have developed a manufacturing method that combines special structural requirements, including specifying spinning speed and undrawn yarn birefringence. It was discovered that a completely new polyester yarn can be obtained which can provide a comb reinforcing cord that has both high strength, zero dimensional stability, and fatigue resistance, and has completed the present invention (C).

That is, the present invention provides (1) a polyester yarn consisting essentially of polyethylene terephthalate, in which the polyester fibers constituting the HoIJx stell yarn have an intrinsic viscosity of 0.65 to 1.1(0); , birefringent straw 160 x 10-" to 200 ), cutting elongation 10-25I6, (e), 0.60.9/d and 0.05&/d for yarn of length 251 standardized to 1000 total denier yarn
The work loss at 150°C was 0.020 to 0.050 by repeating the cycle of stretching and relaxation under the stress between the two, shielded from light, and measured at a strain rate of 1 cm/min. Characteristic polyester yarn for rubber reinforcement and (a) In the production of polyester yarn consisting essentially of 1-polyethylene terephthalate, (b) In the characteristic!1 degree Bo11 ester vS* state of 0.65 to 1.15. The yarn is spun from a spindle with multiple holes (mouth 3.
Set the IF thread speed to 1,500 to 4,000 blades/min. Immediately below the spinning mill (; In the provided heating area, the spinning moderate
Adjust the heating temperature and time so that the relationship between the undrawn yarn 1IljA fold Y (XIO-'') satisfies the following formula (■), Y, ≦Y≦Y, ...・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・■ However, Y, = 3.2X10-@X”+6.OX+4.3 +
++m.

Yl = 7.4X 10-@X" -X+ 26.8
・・・・・・・・・■(1,500≦X≦4,00
0) ・・・・・・・・・・・・・・・・・・・・・
(Suni) Thereafter, the polyester yarn for rubber reinforcement is characterized by being heated and stretched at a maximum stretching ratio of 80 or more, and (E) further, the drawn yarn is heat-treated at 200 to 245°C. This is one method of making it.

In order to further clarify the effects of the present invention, the physical properties of the rubber reinforcing cord obtained from the novel polyester yarn of the present invention are shown in the gi table, and for comparison, JP-A-53-5802
The physical properties of a cord made of conventional polyester yarn obtained from Newsletter No. 8 and No. 53-58031 are shown. The physical property values in the table were unified at 1,000 @ denier for the raw yarn and 500 times/m for each of the former and former emperors in order to make the comparison one-dimensional. The strength in the table is the value obtained by dividing the strength by 9 cord denier, excluding adhesive, and the dimensional stability is the sum of the intermediate elongation of the cord and the dry heat shrinkage straw, as described later, and the smaller the value, the more deformation due to heat. is small and stable, which is desirable. In addition, the fatigue resistance is preferably as long as possible in Guddeyarch Fatigue Test 4.

From this IN, the cord obtained from the polyester yarn of the present invention has a strength of 660~7.0&/d and a dimensional stability of 7.5.
~g, 54, fatigue resistance of 5 to 15 hours, and it is clear that it has well-balanced and optimal physical properties especially as a carcass material for passenger car radial tires.

111 table The present invention will be explained below.

The polyester of the present invention 12 is substantially composed of polyethylene terephthalate having a copolymerization component of 15 molar or less, and is obtained from terephthalic acid by a well-known polymerization method such as transesterification, esterification, HHgT, etc. However, the additives used in ordinary polyester 4, such as matting agents, various stabilizers, etc., are not included. The intrinsic viscosity of a polyester is the relative viscosity divided by the viscosity of the solvent used (ortho-chlorophenol) measured at temperature (3B'C), where C is the degree of polymer in Durham in IE100. ] Calculate.

The intrinsic viscosity of the polyester fiber should be 0.65-1.1, preferably 0.7-1. Most preferably 0.7 from the balance of strength, dimensional stability, and fatigue resistance.
5 to 0.9.5. 0 used in clothing fibers, etc.
If it is less than 65, the dimensional stability improves, but the strength deteriorates.

1. In the above case, as in the present invention (: When spinning at high speed, the yarn frequently breaks just below the cut-off date. 1-1 The spinning that fails is 1-1.

tfI-, multilayer folded book of polyester fiber is 160 x 10
-8 to zoox7o-l is necessary, and belongs to the relatively soft high birefringence class 4. If it is less than 160 x 10'''S, the strength will be low even if the degree of polymerization of polyester is increased.
on the other hand! If it exceeds 0OXIO-"t-, thread breakage occurs frequently during the drawing process, making stable production impossible. The preferred range for multi-layer folded books is 165 x 10-" to 190
X 10-''. ASRR can be made constant using a polarizing particle mirror C nitrite compensator, and in the present invention, the Olympus PC)
The value was constant at 25° C. using olive oil as the immersion medium.

In the present invention, the breaking elongation of the polyester thread is 10 to 2.
5. We need compassion, which is regret. When the elongation at break is less than 1016, the strength decreases significantly during twisting, so that not only is it impossible to obtain a cord with high strength, but also during production, there is excessive breakage during the drawing process, making stable production impossible. Cut 1lt
Polyester yarns with a 4pP degree of more than 25 do not have sufficient strength due to the insufficient molecular orientation associated with stretching C, which does not reach the range specified by the present invention for multilayer folded books. For example,
C: A polyester yarn with high breaking elongation cannot be turned into a cord. The preferred elongation at break of the polyester yarn is 1-1 to 184.

The polyester yarn of the present invention needs to have a strength index of 25 or more, preferably 28 or more within this range of elongation at break. If the strength index is less than 25, a cord with high strength, which is the object of the present invention, cannot be obtained. The strength index here is a value calculated by the following formula.

Strength index = [cutting strength (y/d)) x (cutting elongation (96
)) As a result of research conducted by the present invention, it was found that when polyester yarn is twisted and heat-treated to become a rubber reinforcing cord, the strength of the original yarn and the cord are significantly different. Just because the strength of the thread is high does not necessarily mean that it is a high strength cord. l-5803
The superiority of the present invention will be clear when compared with the strength index of the polyester yarn in Bulletin No. 1, which is 110 to 24.

The polyester yarn of the present invention has an ISO'C work loss of 0.
4F-am preferably 0.02-0.05
．． It is 04.

If the work loss at 150° C. is less than 0.02 Y·1, the cord will exhibit excellent dimensional stability and fatigue resistance, but no matter how high the degree of polymerization of the polyester is raised, a cord with high strength will not be obtained. If the work loss at 150° C. exceeds 0.05 hours, the cord will exhibit high strength, but the dimensional stability and fatigue resistance will be poor, and the object of the present invention will not be achieved. The constant work loss at 150°C is explained in Japanese Patent Application Laid-Open No. 58-580, as described below.
It is easily determined according to the method described in Bulletin No. 31, Publication No. P#U5B-58032. The work loss at 150°C corresponds to the fatigue resistance of the cord, and the fatigue resistance of the Japanese cord, which has a small work loss, is excellent.

It is also a fact that the polyester yarn of the present invention has a relatively low dry heat shrinkage value of 4 to 12 degrees when kept at a constant temperature of 175°C in a hot air bath using a conventional method, and has a relatively low degree of polymerization.
In terms of the balance between strength, dimensional stability, and fatigue resistance when two cords are used, it is desirable that the product of IS 0°C work loss and 175°C dry heat shrink curtain be 0.5 to 0.23.

Next 4: The manufacturing method of the present invention will be explained in detail.

The polyester yarn of the present invention is usually spun by using a well-known layer-spinning device with a spinning machine provided with a heating zone directly below the spinneret, by continuously spinning polyester from a spinneret with a large number of holes. The intrinsic viscosity of the polyester supplied for spinning is 0.65~
1.15 is required.

If the intrinsic viscosity is less than 0.65, the strength of the resulting polyester yarn will be low and the object of the present invention will not be achieved.

1. On tsm, the intrinsic viscosity of the yarn to be spun is 1.1 or more, which causes frequent yarn breakage directly under the spinneret, making stable production difficult. The preferred intrinsic viscosity is between 0.7 and 1, most preferably between 0.75 and 1.

The present invention requires a spinning speed of 1500 m/min to 4000 IL/min, which is one of the important requirements in the structure of the present invention. If the spinning speed is less than 1,500 m/min, although a high-strength polyester yarn can be obtained, the dimensional stability and fatigue resistance when made into cords will not be improved. Although the dimensional stability and fatigue resistance are improved, the strength is low, and not only does the object of the present invention not be achieved, but also the yarn breaks frequently during spinning, making stable production difficult.The preferred spinning speed is 2000.
~3500 WL/min 0 Such a spinning speed range is at most 50 WL/min for conventional rubber-reinforcing polyester yarns.
The actual image speed is extremely high compared to that of 0.011 L/min.

In addition to such a limited spinning speed of 42, the present invention investigates the relationship between the spinning speed It is necessary to adjust the heating temperature and time so that it falls within the range of the following equation.

Y, ≦Y≦Y1 ・・・・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・・・・■ However, Y1= 3.2 X 10-'X” + 6.OX
+ 4.3...■Y, = 7.4X 10"
X” -X+ 26.8・・・・・・・・・■(150
0≦X≦4000) ・・・・・・・・・・・・・・・
・・・・・・■ In order to make the range of the spinning speed and the IJI refraction index of the unfinished filament of the present invention more clearly, they are shown in @len. In the case of 1ull broom, the horizontal axis shows the spinning speed, and the vertical axis shows the multilayer folded book of undrawn yarn. The line connecting points A-B is 2〇.

The curve connecting points C and D is indicated by a circle.' In the part above curve 11A-8 in Fig. 1, the spinning speed is C; the birefringence wheel of the corresponding undrawn yarn becomes high, yarn breakage during spinning and drawing become unstable, and the polyester yarn after drawing increases. The strength index of the cord is less than 25, and the strength of the cord is insufficient. - In the region below @C-D, the multi-layer fold of the undrawn yarn corresponding to the spinning speed decreases, and although the strength of the polyester yarn after stretching increases, the dimensional stability when forming a cord, Fatigue resistance would be insufficient and the object of the present invention would not be achieved.

In the production method of the present invention, the degree of welding and the degree of yarn (2) The degree of yarn that limits the scope of claims to the corresponding undrawn yarn multi-layer folded yarn are extremely novel and the difference from the conventional method is further clarified. C
2.1: IIItR1153-5803 discloses a method for manufacturing polyester yarn with the fatigue resistance mentioned above.
! Example C of the publication; quoting the correspondence between "spinning speed - undrawn yarn I [111 folds"],
It was shown as t-F.

Within the range of ABCD specified in the present invention, it is possible to obtain the polyester yarn of the present invention with extremely high productivity. As is well known, "productivity" is the product of the spinning speed and the drawing wheel, and when obtaining multifilaments of the same total denier, the productivity is high when the value of this product is large. In the conventional production of polyester yarn for rubber reinforcement, including JP-A No. 53-58032, the "productivity" value was at most 2,500 to 3,500, which was 6, but in the present invention, it was 4.
It is surprising that it is much larger, 500-7000. This method makes it possible for the first time to obtain a novel polyester thread as described above. In order to set the relationship between spinning mode and undrawn yarn multi-layer folded fibers within the range defined in the present invention, the temperature and residence time of the general girder heating area immediately below the spinning mill can be adjusted to achieve multi-layer folding corresponding to the spinning speed. l the book
It is adjusted by keeping it within the range that falsifies S by the two straight lines shown in 111II. The heating method may be any method such as an omniscient heating furnace using medium-high frequency electric heaters or a method in which gas heated to a high temperature is sprayed onto the yarn. Adjustment of the heating temperature and time can be appropriately selected depending on the combination of the intrinsic viscosity of the polyester to be spun, the spinning speed, etc. For example, when using a heating section of a set of electric heaters as in Example IIa11, the cylinder length is 20 to 80 degrees, the residence time is 0.005 to 0.05 seconds, and the temperature near the yarn is 100 degrees.
This is possible by setting the temperature to ~350°C. As a more specific example, if the intrinsic viscosity is 0.9, the spinning speed is 2000 m/min, and the heating section is 401, the heating cylinder temperature is 150 to 400 m/min.
By setting the temperature near the yarn at t/100 to 300°C, the undrawn yarn 1 [Jl! Origami is within the scope of the present invention. If the intrinsic viscosity is high or the spinning speed is high, the tube length may be further increased or the heating temperature may be set higher.

The undrawn yarn thus obtained is drawn at a total drawing ratio of 80 folds or more, which is its maximum drawing ratio. If the cord is less than 80 strands, the strength will be insufficient, and even if it is stretched in the post-treatment after twisting, it will not be possible to obtain a high-strength cord. The maximum drawing ratio refers to the highest possible drawing ratio; however, when drawing with this double curtain, the cutting elongation of the drawn yarn becomes 6 to 7 tatami, making stable drawing difficult. Therefore, a good draw ratio is 85 to 95, which is the same as a large draw ratio.

Advantageously, drawing is carried out continuously following spinning according to the well-known direct spinning drawing method, or - drawn as an unsupported drawn yarn in a separate step, or following spinning and then completely drawn. At the stage where a part of the drawing ratio has been drawn, the film may be drawn in a separate step after the film has been drawn to m. It is also a feature of the present invention that the spinning 4:a<drawing can be carried out continuously or arbitrarily divided without impairing the object of the present invention. The stretching may be performed in one stage or in multiple stages of two or more stages. Heating during stretching can be done by any of the well-known methods such as using a heated roll, heating plate, or blowing hot gas onto the yarn. The heating temperature needs to be within the range of the second-order transition temperature of the polyester thread, but is usually preferably 80 to 200°C. If the drawing temperature of the polyester yarn is below 1 secondary dislocation to high temperature, not only will there be many yarn breakages during the drawing, but the shrinkage wheel of the polyester yarn will be large, and the dimensional stability of the cord will be poor.

The drawn polyester yarn is then heated in a tin bath at 150-250°C. This heated tin ffi reduces the dry heat absorption JII table of the polyester yarn at 175℃ to 4 to 12 degrees, further reduces the work loss at 150℃, and improves the dimensional stability and fatigue resistance when made into a cord. It has the effect of If the heating temperature is less than 150°C, this effect will not be sufficient, and if the heating temperature exceeds 250°C, latent melting of the polyester thread will occur and heating tin salt will not substantially be formed. Although it is industrially advantageous to carry out heating tin salt continuously with stretching in the same equipment at a temperature within this range, the effect of the present invention will not be impaired even if heat treatment is performed separately from stretching. No actual method of the present invention) 91: An example of a suitable apparatus is shown in a mis diagram (
a), 佽) and (C), but the invention is not limited to the example of jin.

112al (- and (b) are spinning and drawing heat treatment II!
In an example of a device in which the process is carried out in parts, in Coil 2al(a), polyester is spun in a bath-molten state through a spindle 1 having multiple holes, and the temperature in the vicinity of the yarn is lowered immediately below the spinneret C: installed heating cylinder 2C. is adjusted, and then the cold air 6 blown out from the chamber 3
After being cooled and solidified from the second step, a finishing agent is applied with an oiling roll 4, and then rolled up as an unstretched package 6 while being taken up with a take-up roll 5 at room temperature.

The unstretched package 6 rolled up in a straight manner is II
IWA (b) is supplied to a stretching heat treatment equipment, heated and stretched between nine Godet roll pairs 7-8 and 8-9, and further C = Godet roll pair 9 and / trench 9 are heat treated with Godet roll pair 10 and stretched. It is wound up as a thread 11.

5g5sa is a direct spinning/drawing heat treatment device in which spinning and drawing heat treatment are performed continuously.

As detailed above, the yarn and manufacturing method of the present invention, which skillfully take into account the structural requirements, produce a tire cord suitable as a carcass material for passenger car radial tires, which has high strength, dimensional stability, and fatigue resistance. It can be obtained stably and with high productivity, and its value for a prefecture is extremely large.

The present invention will be described in detail with reference to examples below. In the examples, each constant value was determined to be 0 using the following method. c.
Measurement is performed under conditions of 25° C. temperature and 60° C. humidity at m/min. The strength of the treated cord is calculated using the denier excluding the adhesive.

(Tao 160℃ work loss JP-A-53-58031 and l111153-
According to the method described in the 58032 bulletin, the sample length is 2S1.
The strain rate was set to 1/min, and an autograph manufactured by Shimadzu Corporation was used. First, heat the furnace to 150°C.

Then, measure the denier of the polyester yarn. Then,
Thread C: C so that a stress of 1 fi/d is applied at full scale.
;Determine the full scale load (F8L). Set the crosshead speed to 1 tx/min. 7J in a furnace at 150℃
Q: The heated upper chuck grips the yarn, and the lower chuck also grips the yarn. At this time, adjustment is made so that a stress of 0.01 N/d is applied to the thread.

The length of the thread between the upper and lower chucks is 251 mm. Then start the chart and make a steep descent to the cross. 0
．． 6. Perform a cross-edge reversal with a load that produces a stress of 9/d. The crosshead is then reversed with a load that produces a 0.5 Ii/d stress. Repeat 4 times between 0.6 and 0.5I trends. Next, raise the cross helix to 0.4N/d.
Reverse the dado to the cross with a load that produces a stress of . 0.
Repeat 4 times between 6 and 0.4j/d. Next, raise the crosshead and reverse the crosshead at 0.3IA. In this manner 4 cycles between O] and 0.3jl/d, then 4 cycles between 0.6 and 0.25 dark, then 0
．． 4 cycles between 6 and 0.111/d, the last (:0
．． 4 between 6 and 0.05 AI/d? Continue repeating the cycles. After performing the constant am operation in this manner, the work loss is calculated using the following formula. That is, 0.6 to 0.0 of the above operations! 11 of load cycles of S l/d
Only use data from the fourth cycle. Make a copy of this Hysteresis 1111ii, cut it into pieces, and weigh the paper.

[-cm/cycle/1000 denier/25 scratches] Wtc: Weight of cut curve [l] PAL: Full scale load [hours] CH8: Crosshead speed [17 minutes] Wty: Due to full scale load Weight of paper area generated in 1 minute (j') W: Work loss.

(3) Dimensional stability: Determine the intermediate elongation and dry heat resistance of the cord, and calculate the total value.

Dimensional stability (11=Nakazeki elongation (-10 dry heat convergence (@ intermediate elongation)): When the total denier of polyester yarn is d% and the number of twisted yarns is n, the cord has 2. The elongation is 1 when a tension l) of 25d-a is applied.

Dry heat shrinkage: The cord is heat treated in air at 160° C. for 30 minutes without any load. Length of thread before and after heat treatment fence
By subtracting l and L, the dry heat shrinkage force is calculated using the following formula.

It is.

(4) Fatigue resistance JIei L-1017, 1, 3, 2, 1A method 4: According to the Gutdeyer method, a tap fatigue test was conducted.

Chip shape Inner @ 12.7mm Outer 4126.0Peng Length 230■ Self-height angle Within 95° IE 3.8m/d-Rotation number
A fatigue test was carried out at 950 rpm, and due to the fatigue of the deep
The time required for the tube to burst is fixed.9.

The physical property values of the pots in the table of Examples are expressed as follows.

Δn: Double shoulder folding (X10-s) T-8: Cutting strength (jl/d) T-8: Cutting elongation (@ T, F: Strength index 682 150°C work loss (V-儂) Example 1゜Polyester yarn for tire cords with 1000 denier 7384 filaments was obtained by spinning and drawing heat treatment using the apparatus shown in Figure 2 (a) and (b). Poly1J ethylene terephthalate with a viscosity of 0.90 is spun at a spinning A temperature of 295°C, and the vicinity of the yarn is heated at 310°C using a heating cylinder 2 with a length of 50aa.
After cooling and solidifying with 20°C cold air blown from chamber 3, applying a spinning finishing agent with oiling meal 4, and then turning the spinning wheel 11Rc1-5 rotating at room temperature to 11
The speeds shown in Table 2 were set to obtain unstretched packages. Next, this unstretched Padacage was heated to 100° C. using a stretching heat treatment apparatus shown in FIG.
Same 8v 130℃, same 9 210℃, between 7-8, 8-8
After stretching in two stages for 9 minutes, the yarn was heat-treated at 230° C. using a godet roll pair 9 and a fllllO rotating at the same speed as the Godet roll pair 9, and rolled up as a drawn yarn badakage 11.

The intrinsic viscosity of the nine polyester yarns obtained was 0.86. The physical properties of these polyester yarns are shown in Table 4.

These polyester yarns were twisted using a ring twisting machine.
Create a pre-twisted cord by applying 8 twists/III, and apply Z twist of 500 times/@ to 2 of Jin's pre-twisted cords to create a 222
I got a code of 0d. Convert this code to Litmler C
The depth cord was removed using an amplifier. The physical properties of this ;-de are shown in Table 112.

As is clear from Table 2, a rubber reinforcing cord with high strength, excellent dimensional stability, and fatigue resistance can be obtained from the polyester yarn defined in the present invention.

Below is the margin Example 2゜Example 1. The temperature in the heating area immediately below the spinneret and the spinning speed were set as shown in Table 3 to obtain undrawn yarns with different birefringence. These undrawn yarns were drawn and heat treated under the same conditions as in Example 1, and the physical properties of the edible polyester yarns and the physical properties of the cords are shown in 111311.

Below is the margin Example 3゜Example 1. Similar to 1:lll12 Figures (a), (b)
II! The degree of polymerization of the polyethylene prephthalate used was changed, spinning was carried out at a constant spinning speed of 113,100 m/min, and the yarn was abrasively drawn to obtain a drawn yarn having an intrinsic viscosity shown in Table 4 of 11g. The birefringence curtain of the undrawn yarn in spinning 52 was adjusted to the values shown in Table 114 by adjusting the heating area directly below the spinneret by a combination of the heating length and degree a. When using this method, it was difficult to obtain undrawn yarn continuously due to yarn breakage under the spinneret during spinning, which caused the extrudate to exhibit an extrudate viscosity of 1.12.

The drawing heat treatment place for the obtained undrawn polyester yarn is shown in Example 1.
It was conducted under the same conditions.

The physical properties of the obtained drawn yarn and the physical properties of the cord are shown in Table 1g3.

As is clear from this table, a cord with dimensional stability, fatigue resistance of 1 = 1, and high strength can be obtained from polyester yarn having an intrinsic viscosity of 62.

Example 4゜ Regarding the undrawn yarn of Hatobo of Example 3, the drawn double-strength 115
It was drawn at the ratio shown in the table to obtain a stretched yarn.

The physical properties of these drawn yarns and the physical properties of cords and cords according to Example 1 are shown in srs*.

Below is a margin Example 5゜A drawn polyester yarn with a viscosity of 0.92 is obtained using the equipment shown in Figures (sl) and (b) with g-nee 112 as in Example 1; spinning mode: 2500 m/min; 2 heated sections with a length of 50 aa; the vicinity of the twisted yarn is heated to 320°C, and the birefringence index is 3.
An undrawn yarn of 0x10'''' was obtained. This Minobu Okito Conference 2
Godet roll pairs 7, 1, 9. Th! The temperature of the polyester yarn was set as shown in the t-ms table of 10, and the resulting polyester yarn cost $199 as a drawing package 11.

Below is a margin Example 6゜1g3 Direct spinning drawing heat treatment method 6:1 by using the apparatus shown in the figure
A polyester yarn for tire lard with a filament of 1,500 denier and 1,000 denier was obtained. That is, using a casting spout 1 having 500 spinning holes, polyethylene terephthalate with an intrinsic viscosity of 0.76 was spun at a spinning temperature of 290°C, and a length of 40
Heated to 140°C near Mugijo by aa heating tube snow,
Cold air C at 20° C. blows out from the chamber 3: After cooling and solidifying, a spinning finisher is applied with an oiling roll 4, and then taken up with a take-up roll S at room temperature that rotates at 3300+a/min. The multilayer folded book of undrawn yarn at this stage is 28×10
-1. The unstretched film was continuously heated at 100°C and 125°C without being rolled.

7. Godeztrol at 220°C and 200°C. s.

9.10, 2-71 5stS hot drawing was carried out, and it was rolled up as a drawn yarn package 11. The intrinsic viscosity of the obtained polyester yarn was 0.73. Strength 8.31ya
, pF degree 11 o 2 intensity index 27.5. Birefringence 18!
Xl0-1. 175"C dry heat absorption 9.1 saliva.

The work loss at 150°C was 0.031. This polyester yarn was obtained by the same treatment as in Example 1, and had a strength of 6.411/d, a dimensional stability of S and O, and a fatigue resistance of 11 hours, and was particularly suitable for passenger car radial tires (F).
: #- Suitable as waste material.

Comparative Example 1 Polyethylene terephthalate with a viscosity of 11 [0.95] was spun at a temperature of 3 according to the method disclosed in JP-A-83-58032
Spun at 10°C, quenched with cold air directly under the spinneret, followed by the same procedure as in Example 4, drawn at 100 (Ia/min), and continuously stretched at a drawing ratio of 3.1 times C at 3100 sa/min. The birefringence of the undrawn yarn was 19×101.The intrinsic viscosity of the drawn yarn was 0.91, the cutting strength was '1.51/d, the cutting elongation was 7.2'l, and the strength index was 20°. Multilayer folded book 168X10
--175℃ dry heat loss 5.7 hours, 150℃ work loss o
, oig drawn yarn was obtained.

The nine codes obtained by processing in the same manner as in Example 1 had an intensity of 5. ON/
d, the dimensional stability was 7.6 points, the fatigue resistance was 17 hours, and the dimensional stability was good, and the fatigue resistance was 9I, but the strength was low and it was unsuitable as a rubber reinforcing material.

Comparative Example 2 According to the method of JP-A No. 53-58028, the proper word f
Jlo, 72 polyethylene terephthalate was spun at a spinning temperature of 290°C, a heating tube with a length of 30em was installed just below the spinneret, and the vicinity of the yarn was set at 220°C, according to Example 4.
It was pulled at a speed of 5 m/min. The multi-layer folded book of undrawn yarn at this stage is 2. It was OX 10-s. The undrawn yarn was drawn continuously at a drawing ratio of 5.8 times without being rolled up once.
As a drawn yarn at 2900m/min! @II-z good.

The obtained drawn yarn has an intrinsic viscosity of 0.69. Cutting strength 8.7j
l/d, cutting elongation 949 strength index 26. @Refraction Wara 201
X10=, 150°C work loss was 0.066.

The cord obtained from this drawn yarn has a strength of 6, ON/d,
Dimensional stability 9,746. The fatigue resistance was 2 hours, making it unsuitable for use as an orcus material.

[Brief explanation of the drawing]

FIG. 111 is a graph showing the relationship between spinning speed and birefringence of undrawn yarn, which are constituent elements of the production method of the present invention. Figure 2 (a) and (b) are typical equipment layout diagrams for producing the polyester yarn of the present invention, and Figure 2 (sl
> indicates the spinning device, lI2 (b) is the spinning device shown in Fig. 112 (a).
Figure I3 shows an example of a direct spinning drawing heat treatment apparatus for producing the polyester yarn of the present invention. 1... Spinneret, 2... Heating cylinder, 3...
...chamber, 4...oiling roll,
5... Take-up roll, 6... Unstretched package, 7-10... Godet roll pair group, 1
1...Drawn yarn package. Patent Ratio/Genjin Asahi Kasei Industries Co., Ltd. Patent ratio 1st Patent Attorney Akira Aoki S II Patent Attorney Kazuyuki Yamaguchi Figure 1 Spinning speed X (m/min) Figure 2 Figure 3rI! I (0)

Claims (1)

[Claims] 1891 polyester fiber yarn 4 made of polyethylene terephthalate, - the polyester fibers constituting the polyester yarn are (a) 11111 viscosity 0.65 to 1.1 (b)
A polyester yarn having a diameter of 160 x 10-'' to 200 x 10'' is cut to (c) strength index of 25 or more [however, strength index = (cutting strength) x (cutting elongation) ★] Elongation 10-254 (e) Standardized to 1000 denier thread, length 2.5 billion thread (: 0.60j'/d and 0.50j
It has a work loss of 0.02 to 0.05 h·1 at 150°C, measured at a strain rate of 117 minutes after repeated cycles of elongation and relaxation at a stress between l/d. A polyester yarn characterized by: λ In the production of polyester yarn consisting essentially of polyethylene terephthalate, (a) polyester having an intrinsic viscosity of 0.65 to 1.15 is spun in a molten state through a spinneret with many holes, and IP),
The spinning speed is t'1,500 to 4,000 m/min, (c),
In the heating zone provided immediately below the arrival in Japan, the relationship between the spinning speed X (m/min) and the undrawn yarn birefringence curtain Y (XIO-'') is expressed by the following formula (13
Adjust the heating temperature and time to satisfy 1', Y, ≦Y≦Y1 ・・・・・・・・・・・・
・・・・・・・・・・・・・・・■ However, in the formula 0, Y, = 3.2 X 10-', X" + 6.0X
+ 4.3 ・−・・・−(21Y,=7.4X10”
−・X”−X+26.8 ・・・・−・−@(1,5
00≦X≦4,000) ・・・・・・・・・・・・
・・・・・・・・・■), then heat-stretched at a maximum stretching ratio of 80 or more, and further heat-treated the drawn yarn at 150 to 250°C.
A method for producing polyester yarn characterized by: