JPH01292133A - Machine sewing thread and production thereof - Google Patents

Abstract

PURPOSE:To provide a machine sewing thread excellent in heat resistance without causing yarn breakage and fluff, by melt spinning a linear polyether ether ketone of a specific structure, drawing and heat-treating the resultant yarn, primarily twisting the obtained yarn at a specific twist coefficient, setting twists, finally twisting the yarn and setting the twists. CONSTITUTION:A polymer having recurring units consisting of >=85% linear polyether ether ketone expressed by formula I is melted, spun at 360-390 deg.C spinneret temperature, drawn and heat-treated to provide a drawn yarn, which is then subjected to primary twist so as to afford 3000-12000 twist coefficient (K) expressed by formula II (T is the number of twists; DC is denier of the multifilament yarn) and twist setting at >=160 deg.C. The plural obtained yarns are then doubled and subjected to final twist so as to provide 3000-15000 twist coefficient (K) and subsequently twist setting at >=180 deg.C so as to afford <=20T/m untwisting torque (T). Thereby, the aimed machine sewing thread having >=4.5 g/de strength (St) expressed by formula III (El is elongation), >=20 silk factor (SF) and <=8.0% dry heat shrinkage factor (HS) at 220 deg.C is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a sewing thread made of polyetheretherketone fibers having excellent heat resistance and chemical resistance, and a method for producing the same. The present invention relates to a sewing thread made of polyetheretherketone fibers that has improved shrinkage properties and is also easy to handle; and a method for producing polyetheretherketone sewing threads that have very little occurrence of fluff due to thread breakage.

(Prior art) Conventionally, materials for sewing thread include natural fiber materials such as cotton thread and silk thread, polyester 1liIff, nylon fiber,
Synthetic fiber materials such as vinylon m-fiber are widely used.

On the other hand, in recent years, its uses have become more diverse and it has become more heat resistant.

Sewing thread with excellent chemical resistance is also in demand.

In order to meet this requirement, the above materials have limitations, so attempts are being made to use materials other than those mentioned above. for example,
Japanese Utility Model Publication No. 52-87736@ discloses a sewing thread made of polymetaphenylene isophthalic 7-mid fiber. However, this polymetaphenylene isophthalic 7-mid fiber has room for further improvement in terms of heat and humidity resistance, especially chemical resistance (alkali resistance and acid resistance). Although fluoropolymers are known as materials with excellent acid and alkali resistance, fluoropolymers have a low strength of 1 to 2.5 a/de, so there is still room for further improvement when used as sewing thread. .

Although it has been hoped that a sewing thread with excellent heat resistance, chemical resistance, and mechanical properties (mechanical properties) would appear, the reality is that it does not exist as a commercial product.

(Object of the Invention) The first object of the present invention is to provide a sewing thread made of polyetheretherketone fibers having excellent mechanical properties and dimensional stability, and a method for producing the same.

A second object of the present invention is to provide a sewing thread made of polyetheretherketone Im that is easy to handle, and a method for producing the same.

The third object of the present invention is to provide yarn breakage 1 in industrial production.
It is an object of the present invention to provide a method for producing sewing thread made of polyetheretherketone fiber with extremely low fuzz generation.

(Structure) The present inventors have made repeated studies to achieve the above object, and as a result, have arrived at the present invention.

That is, the present invention consists of the following configuration.

(1) A sewing thread which is provided with a first twist and a first twist, wherein the constituent polymer of the sewing thread is substantially polyetheretherketone, and further satisfies the following [1] to [4] at the same time.

■ The strength (St) of the sewing thread is 4.5c+/de or more and the silk factor (SF) is 20 or more.

■ Dry heat shrinkage rate (H8) at 220°C is 8.0% or less.

■ The medium thread denier of the polyetheretherkene fibers constituting the sewing thread is 2 to 10.

■ The untwisting torque <-r> of the sewing thread is 20 T/m or less.

2) 85% or more of t/A repeat unit is 10-@r-0
A linear polyetheretherketone consisting of Beφ)-coXζX is melted and spun at a spindle temperature of 360 to 390°C,
A method for producing sewing thread, which is then subjected to drawing heat treatment to obtain a drawn thread, followed by the following operations (1) and (2).

■ The drawn yarn has a twist coefficient (K) of 3000 to 12000.
The first twist is applied to give a twist of at least 160
Perform twist setting at a temperature of ℃ or higher.

■ Combine multiple multifilaments obtained in ■,
Ply twisting is applied so that the twist coefficient (K) is 3,000 to 15,000, and then untwisting is performed at a temperature of 180° C. or higher so that the untwisting torque (T> is 20 T/m or less).

The present invention will be explained in detail below.

The sewing thread of the present invention has excellent mechanical properties, with a strength (St) of 4.5/de or more and a silk factor (SF) of 20 or more. That is, the strength (St) is 4.5g/
If the silk factor (SF) is less than 20, the mechanical suitability as a sewing thread is poor, so thread breakage occurs frequently during sewing thread processing, and even skipped stitches occur, resulting in poor sewing. Sex itself is insufficient and cannot be of any practical use. As mentioned above, there are no detailed reports on sewing threads made of polyetheretherketone fibers, and the sewing machine system made of polyetheretherketone fibers of the present invention is industrially extremely effective as a "practical sewing thread." be.

Next, the sewing thread of the present invention has a dry heat shrinkage rate of 220°C (
+-18) or less than 8.0%, which shows extremely good dimensional stability.

In general, if the dimensional stability is poor, puckering will easily occur during the consumption process of the sewn product, which is undesirable.In particular, sewn products using sewing thread will pass through high temperatures of 220°C or higher during the setting process of the fabric. Therefore, the sewing thread itself is required to have single-method stability at high temperatures. As a guideline, the dry heat shrinkage rate (H5) at 220°C can be adopted. That is, the dry heat shrinkage rate (H3) at 220°C is 8.
If it exceeds 0%, the dimensional stability at high temperatures will be poor and the seam appearance will be undesirable. Furthermore, since the sewing machine of the present invention has a small untwisting torque (T) of 20 T/m or less, no snarl occurs during use, and it is extremely easy to handle.

Further, the single yarn denier of the polyether ether ketone fibers constituting the sewing thread of the present invention is preferably 2 to 10 deniers, preferably 3 to 7 deniers. If the single yarn denier is less than 2 denier, it is not preferable because the productivity up to the production of sewing threads is significantly reduced. That is, when the single yarn denier is less than 2 denier, yarn breakage during spinning and drawing process,
Single thread breakage.

This is because fuzz occurs frequently, and furthermore, fuzz occurs frequently due to thread breakage during the subsequent twisting/letting process.

On the other hand, if the single thread denier exceeds 10 denier, the sewing thread becomes stiff and difficult to bend, making it impossible to form neat stitches, which is undesirable.

In order to manufacture sewing thread having the above characteristics, it is important to adopt the following manufacturing method.

First of all, the polymer ether ether ton,
More than 85% of the repeating units have a right viscosity [η] of 0.7 or more (measured using concentrated sulfuric acid, humidity 25°C)
It is preferable that the polymer has a glass transition point of 145°C and a melting point of 345°C as measured by DTA. In order to manufacture sewing thread with excellent physical properties using such polymers, it is first necessary to make the raw yarn (drawn yarn) used for manufacturing sewing thread sufficiently high in strength and silk factor. be. During spinning, it is important to set the spinneret surface temperature to 360-390°C. If the die surface temperature is less than 360°C, the die temperature will be too low, and the physical properties of the raw yarn (drawn system) will be insufficient, and the spinning process will be difficult.

Yarn breakage and medium thread breakage in drawing n4 increase, and productivity also decreases. Therefore, fuzz is also used when manufacturing sewing thread.

This is undesirable because thread breakage occurs, and the obtained sewing thread physical properties are not satisfactory.

On the other hand, if the die surface temperature exceeds 390° C., the temperature is too high, the polymer tends to deteriorate, the spinnability decreases, and the drawability also decreases, which is not preferable.

On the other hand, the spinning speed is less than 1000 m/min, preferably 200 to 800 m/min. Spinning speed is 1
If the spinning speed exceeds 000 m/min, there are disadvantages such as an increase in yarn breakage during m-spinning (and an increase in single yarn breakage during the IIL drawing process).If the spinning speed is 200m/min without swirling, , productivity decreases.

Here, the spinning equipment has a spinning temperature of 390 to 420°C.
Existing equipment used for polyester can be used as is, as long as the equipment is capable of high-temperature spinning. In addition, in the present invention, optimization of the spinneret surface temperature leads to high productivity and
Since it is important to satisfy high properties, it is necessary to control the spinneret surface temperature by adjusting the temperature around the spinneret surface and the temperature of the heating cylinder installed directly above and below the spinneret. Next, stretching and heat treatment operations are performed, but in the present invention, for example, the surface roller temperature is 100 to 150.
C. and 180 to 250.degree. C., stretching heat treatment between rollers, and then stretching through cooling rollers can be adopted. Of course, only one stage of stretching is required, and multi-stage stretching can also be employed. Further, the stretching speed is not necessarily limited, and a normal stretching speed, for example, about 100 to 800 m/min may be adopted.

The raw yarn (drawn yarn) thus obtained has a strength of 5.
At 0 g/de or more, the silk factor is 23 or more, and the mechanical properties are excellent. Next, using the raw thread (drawn thread), a sewing thread is created as described below.

First, a first twist is applied with a twist coefficient (K) in the range of 3,000 to 12,000. At this time, when the twist coefficient is less than 3000,
The convergence of the sewing thread becomes insufficient! i! During manufacturing, the sewing thread tends to separate into raw fibers on the surface of the fabric, which is undesirable.

On the other hand, when the twist coefficient (K> exceeds 12,000), the internal strain of the vA navy blue becomes large during twisting, resulting in a large decrease in strength, which is not preferable.

Next, it is necessary to heat set the twisted multifilament and stop the untwisting torque. In the case of polyethylene terephthalate, the purpose can usually be fully achieved under moist heat or heating at temperatures below 130°C, but in the case of polyetheretherketone fibers, the torque does not decrease at this temperature and untwisting] The silk is extremely large and has many snarls, making it extremely difficult to handle. Therefore, it is necessary to set it at a higher temperature, which requires a temperature of at least 160°C or higher. Specifically, the surface temperature is 160
This can be easily carried out by using a roller heated to a temperature above .degree.

Finally, a plurality of the above-mentioned twisted multifilaments are combined to give a ply twist. The direction of the top twist is opposite to the direction of the first twist, and normally the first twist is an S twist, and the first twist is a 2 twist.

In the production of normal sewing thread, the number of top twists is equal to the number of bottom twists.
A range of 0 to 90% is used. This condition can also be adopted for sewing thread made of polyetheretherketone giN, and the twist coefficient (K> is preferably in the range of 3000 to 15000. This was set from the viewpoint of reducing torque, for example, Twist coefficient is 3000-1 (first twist: S
direction.

When twisting (ply twist: 2 directions), the torque in the Z direction becomes large,
Moreover, when it exceeds 15,000, the torque in the S direction becomes large, so even if set at a high temperature, the untwisting torque exceeds 20 T/m, which is undesirable because the handleability as a sewing thread deteriorates.

Here, the setting temperature for ply twisting is preferably 180° C. or higher. When the setting temperature is less than 180℃, ■ the twisting effect is insufficient and the untwisting torque is 20 T/m or more; ■ the dimensional stability as sewing thread (especially at high temperatures) is insufficient, such as The dry heat shrinkage rate at 220° C. exceeds 8.0%, which is not preferable.

The setting method for the first twist is the same as the setting method for the second twist.
Surface roller temperature 180°C or higher, preferably 200″C
It is convenient to use the heating roller described above. In addition, it is more preferable that the untwisting torque of the sewing thread is set to IOT/m or less. Further, in order to improve the smoothness of the ply-twisted set yarn as a sewing thread, it is preferable to apply 1 to 5% (for 1,000 fibers) of an oil agent made by adding mineral oil to silicone oil.

(Function and effect) Conventionally, sewing thread that satisfies all of heat resistance, chemical resistance, mechanical properties, and ease of handling, and the technology that can produce the sewing thread in an industrially stable manner with less thread breakage, have been established. There wasn't. In this regard, according to the present invention, it is made of polyether ether ketone fibers with excellent heat resistance and chemical resistance;
It has excellent mechanical properties with a strength of 4.5 g/de or more, a silk factor of 20 or more, and excellent dimensional stability with a dry heat shrinkage rate of 8.0% at 0220°C.■ Single yarn denier is 2 to 10%. It is possible to industrially and stably produce sewing thread that is thin and has excellent properties such as ■ untwisting torque of 207/m.

(Example) The present invention will be further explained below with reference to Examples.

The physical properties used in this example were measured by the following method.

(1) Strength (St), elongation (El) Measured at room temperature 25°C and temperature 60% using a regular tensile tester.
A stress-elongation curve was obtained under the conditions of a sample length of 20 cm and a tensile speed of 200 mm/min, and the elongation I at the point where the stress was maximum.
Read f([1). Moreover, the value obtained by dividing the maximum stress by the fineness of the sample was defined as the strength (St).

(2) Dry heat crimp rate at 220°C A multifilament "skein" was made and treated in a dryer set at 220°C for 30 minutes under no load, and the shrinkage rate was determined from the following formula.

1o −1+ Shrinkage rate (%) = xlO0 (3) Silk factor (SF) It was determined from the following formula using the values of strength (St) and elongation (El) determined in (1).

5F=St (g/de) x J El (%) (4
) Occurrence of yarn breakage Yarn breakage in the process of applying the first twist and second twist was qualitatively evaluated.

(5) Fluff 2 occurrence status The surface of the sewing thread was visually inspected using i3 and evaluated qualitatively.

(6) Ff'f - Twisting torque (T/m) Apply a load equivalent to 1 mg/de to the twisted yarn and leave it until the load stops. (Hang the load and wait.) Next, measure the number of twists at this time. The number of twists is Asano Kikai (1
1. Measured with a test string of 50 cm using a test twister, ]-/
It was refrigerated to m.

(7) Twisting coefficient (K>) It was determined by the following formula from the number of twists (T) and the denier (D>) of the multifilament to be twisted.

K=TXJ Example IcI PEEKPA fat (vtctrex■Crate 1
A chip of 50G) was dried in a hot air dryer at 180°C for 4 hours, melted at 340°C, and had a hole diameter of 0.45φ and a land length of 0.
．． It was extruded from a spinneret equipped with 48 round holes of 90 m [lI].

At that time, as shown in Table 1, the spinneret temperature, spinning speed, and discharge amount were changed so that the resultant was 200 de/48 fil after stretching.

Next, the warped undrawn yarn was heated to a surface temperature of 115°C and 22°C.
Stretching was performed between rollers at 0° C. and rolled up through cooling rollers at a speed of 350 m/min. The total stretching ratio in each experiment is shown in Table 1.

Subsequently, the above-mentioned drawn yarn was subjected to the following treatment to produce a sewing thread. First, 200 de/48 fil was first twisted with S, then heat treated with a high temperature roller (at a speed of 100 m/min), and then rolled up through a cooling roller.

Next, line up three of these to make 600de/144fil.
Then, Z ply twist was applied, and then a high temperature roller (speed 10
0111/min), and after cooling with a cooling roller, a silicone oil is applied to the fiber.
t%), wind up, and make sewing thread.

In addition, the twist coefficient and set temperature at the time of applying the first twist and the first twist are shown in Table-1.

Table 2 shows the physical properties of the obtained sewing thread and the occurrence of thread breakage and fluff during the sewing thread making process.

Table 1 Table 2 In Comparison/Comparative Example 1, due to the low spindle temperature, there were many yarn breaks during the spinning and drawing steps, and the first twisting was performed subsequently.

Yarn breakage occurred frequently during ply twisting.

Examples 1 to 3 and 4 to 6 are preferred examples of the present invention, and were sewing threads with excellent mechanical properties and dimensional stability.

In addition, in terms of quality, there was no fuzz and a good appearance was achieved. Furthermore, the process passability during production was also extremely good.

In Comparative Example 2, the temperature of the spinneret 1 was too high, so there was room for improvement in the process condition during spinning and drawing and in the yarn breakage when applying the first twist and final twist.

- In Comparative Example 3, the first twisting temperature was low, the first twisting property was extremely poor, and during final twisting, there were many yarn breaks at the guide due to snarls, and there was a lot of fuzz.

In Comparative Example 4, the number of twists during the first twist was low, so the convergence as a multifilament was insufficient, and during the subsequent second twist, yarn breakage due to single yarn υ1 occurred frequently. Also, there was a lot of fluff.

In Comparative Example 5, there were too many twists in the first twist, the strength of the sewing thread was low, and the untwisting torque was also large, resulting in poor handling.

Comparative Example 6 lacked ply twist, and Comparative Example 7 had too much ply twist, the balance between S twist and 2 twist was lost, the loosening Mi/Lux was extremely high, and the handleability was extremely poor.

In Comparative Example 8, the setting temperature after ply-twisting was low, so the setting temperature was 220°C.
The dry heat shrinkage rate was high, and the dimensional stability at high temperatures was insufficient. Furthermore, the twist-preventing properties were insufficient, and the handleability was also not good.

In addition, the occurrence of fuzz and thread breakage described in the present invention is as follows:
According to the definition below.

[Fuzz condition] O: Hardly seen on external inspection.

Δ: Small fuzz is observed upon external inspection.

X: Large fluffs are easily found upon visual inspection.

[Thread breakage occurrence] 0:0 to 1 time of thread breakage in 10 hours of continuous operation*:
〃 〃 2 to 3 times x: At a continuous operation rate of io hours, yarn breakage is 4 or more times with this ring twisting machine at a speed of 20 m/
Next, using the sewing thread of Example 2, polyester 65
%, 35% rayon plain woven fabric (basis weight 180Mcm2)
When four sheets were stacked and sewn at a sewing speed of 22 b00 rp, no cutting of the sewing thread occurred within 3 minutes. Furthermore,
Good sewing performance and almost no skipped stitches occurred.

Next, the moisture and heat resistance of the sewing thread of Example 2 was examined.

Alkali resistance and acid resistance tests were conducted. For comparison, polymetaphenylene isophthalamide 1! sewing thread (600 de /300 fil, lower twist coefficient 6)
800. A ply twist coefficient of 10!100 was used.

The results are shown in Table-3. The strength retention rate in the table was calculated as (strength after treatment/strength before treatment) x 100 (%).

Table 3 The sewing thread of the present invention had excellent properties in all of alkali resistance, acid resistance, and heat and humidity resistance.

Claims (2)

[Claims] (1) A sewing thread which is provided with a first twist and a first twist, wherein the constituent polymer of the sewing thread is substantially polyetheretherketone, and further satisfies the following [1] to [4] at the same time. [1] The sewing thread has a strength (St) of 4.5 g/de or more and a silk factor (SF) of 20 or more. [Sicle factor (SF) is the strength of sewing thread (St
) and the elongation of sewing thread (El) using the following formula. SF=St (g/de)×√(El (%))] [2] Dry heat shrinkage rate (HS) at 220°C is 8.0%
Must be below. [3] The single yarn denier of the polyetheretherketone fiber constituting the sewing thread is 2 to 10. [4] The untwisting torque (T) of the sewing thread is 20 T/m or less. (2) Melt a linear polyetheretherketone in which 85% or more of the repeating units consist of ▲mathematical formula, chemical formula, table, etc.▼, and melt the base at a temperature of 360 to 39
A method for producing sewing thread, which comprises spinning the thread at 0°C, then subjecting it to drawing heat treatment to obtain a drawn thread, and subsequently performing the following operations [1] and [2]. [1] The drawn yarn has a twist coefficient (K) of 3000 to 1200.
0, then at least 16
Perform twist setting at a temperature of 0°C or higher. [2] A plurality of multifilaments obtained in [1] are spliced together, ply-twisted so that the twist coefficient (K) becomes 3,000 to 15,000, and then an untwisting torque is applied at a temperature of 180°C or higher. Twist setting is performed so that (T) is 20T/m or less. [The twist coefficient (K) was determined by the following formula from the number of twists (T) and the denier (D) of the multifilament to be twisted. K=T×√D〕