JPH01272841A - Machine sewing thread made of polyphenylene sulfide fiber and production thereof - Google Patents

Abstract

PURPOSE:To obtain the subject machine sewing thread having excellent alkali resistance, heat-resistance and moist-heat resistance, by melting a linear polyphenylene sulfide and subjecting the molten polymer to spinning, drawing and heat-treatment under specific condition. CONSTITUTION:A linear polyphenylene sulfide containing phenylene sulfide unit accounting for >=85% of the recurring unit is melted, spun at spinneret temperature of 310-330 deg.C and a spinning speed of <=1,000m/min and then drawn and heat-treated to obtain a drawn yarn. Said drawn yarn is applied with a primary twist with a twist coefficient (K) of 3,000-12,000 and subjected to twist- setting treatment at >=140 deg.C. Plurality of the obtained multi-filament are doubled, applied with secondary twist with a coefficient K of 3,000-15,000 and subjected to twist-setting treatment at a temperature between 180 deg.C and the melting point of the fiber to attain an untwisting torque (T) of <=20T/m and obtain the objective machine sewing thread having a strength of 3.0g/de, silk factor of >=18, dry-heat shrinkage of <=8.0% (at 220 deg.C) and a single fiber denier of 2-10.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a sewing thread made of polyphenylene sulfide fiber having excellent heat resistance and chemical resistance, and a method for producing the same. More specifically, the present invention relates to a sewing machine made of polyphenylene sulfide fiber that has improved mechanical properties and shrinkage characteristics and is also easy to handle, and an industrial method for producing polyphenylene sulfide sewing thread that has extremely low occurrence of thread breakage and fuzz.

(Prior Art) Conventionally, natural fiber materials such as cotton thread and silk thread, and synthetic W4 fiber materials such as polyester fiber, nylon fiber, and vinylon fiber have been widely used as materials for sewing thread.

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 demand, the above materials have limitations.
Materials other than those mentioned above are also being tried.

For example, Japanese Utility Model Application Publication No. 52-87736 describes a sewing thread using polymetaphenylene isophthalamide fiber. However, this polymetaphenylene isophthalamide fiber has excellent moisture and heat resistance, especially chemical resistance (alkali resistance and
There is still room for further improvement in terms of acid resistance. still,
Fluoropolymers are known as materials with excellent acid and alkali resistance, but fluoropolymers have a strength of 1 to 2.
．． Since it has a low value of 5(]/de, there is room for further improvement as a sewing thread.

On the other hand, by taking advantage of its excellent heat resistance and chemical resistance,
Polyphenylene sulfide is rapidly beginning to be used in the electronics, automobile, and machinery fields. Many proposals have been made regarding its fiberization (for example, JP-A No. 52-30609, JP-A No. 58-2
No. 04047, Japanese Unexamined Patent Publication No. 143518/1983,
(Japanese Patent Application Laid-Open No. 61-75812).

However, with conventional proposals, (a) only monofilaments with extremely large wire diameters can be obtained; (b)
In terms of physical properties, only unsatisfactory results have been obtained, and even more so (
C) There have been no reports on sewing thread made of multifilament, which has excellent physical properties. Therefore, there is a strong need for a sewing thread made of polyphenylene sulfide fibers having excellent mechanical properties and good dimensional stability, as well as industrial production technology for the same, as in the present invention.

(Objective of the Invention) A first object of the present invention is to provide a sewing thread made of polyphenylene-rich nalphide fiber 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 polyphenylene sulfide m-fiber that is easy to handle, and a method for producing the same.

The third object of the present invention is to solve the problem of yarn breakage 2 in industrial production.
It is an object of the present invention to provide a method for producing sewing thread made of polyphenylene sulfide fiber with extremely low fuzz generation.

(Structure) As a result of repeated studies to achieve the above object, the present inventors have arrived at the present invention.

That is, according to the present invention, (1) in the sewing thread that has been given the upper twist and the lower twist, the constituent polymer thereof is substantially polyphenylene sulfide, and further satisfies the following requirements [1] to [4] at the same time. A sewing thread made of polyphenylene sulfide fiber that is characterized by:

■ The strength (St) of the sewing thread is 3. OC! /de or more and silk factor (SF) is 18 or more.

■ Dry heat shrinkage rate at 220'C (H3> is 8.0%
Must be below.

■ The single yarn denier of the polyphenylene sulfide fibers constituting the sewing thread is 2 to 10.

■ The untwisting torque (T) of the sewing thread must be 20T/m or less.

(2) Linear polyphenylene sulfide in which 85% or more of the repeating units are phenylene sulfide is melted, the spinneret temperature is 310 to 330°C, and the spinning speed is 1000 m/
1. A method for producing sewing thread made of polyphenylene sulfide fiber, which comprises spinning the fiber for less than 10 minutes, then subjecting it to drawing heat treatment to obtain a drawn thread, and subsequently performing the following operations (1) and [2].

■ The drawn yarn has a twist coefficient (K> of 3000 to 12000).
and then at least 140'
An operation in which twist setting is performed at a temperature of C or higher.

■ A plurality of multifilaments made into 1q by the operation of ■ are twisted together, and a twist is applied so that the twist coefficient (K> is 3000 to 15000), and then an untwisting torque is applied at a temperature of 180°C or higher and below the melting point. (An operation to set the twist so that T> is 20T/m or less.

is provided.

The present invention will be explained in detail below.

The sewing thread of the present invention has a strength (St) of 3.0 CI/de.
As mentioned above, it has excellent mechanical properties with a silk factor (SF) of 18 or more. That is, the strength (St) is 3.0
If the silk factor (SF) is less than g/de and less than 18, the mechanical properties as a sewing thread are poor, so thread breakage occurs frequently during sewing thread processing, and skipped stitches are also likely to occur during sewing. Sex itself is insufficient and cannot be of any practical use. As mentioned above, there are no detailed reports on sewing thread made of polyphenylene sulfide fibers.
In addition, even if threads made of conventional polyphenylene sulfide fibers were made, the above physical properties could not be obtained, but the sewing threads made of polyphenylene sulfide of the present invention have
It is extremely effective industrially as a "practical sewing thread."

Next, the sewing thread of the present invention has a dry heat shrinkage rate (H
3) is 8.0% or less, which indicates extremely good dimensional stability.

In general, if the dimensional stability is poor, puckering tends to occur during the consumption process of the sewn product, which is undesirable.In particular, sewn products using the sewing thread of the present invention may be heated to temperatures of 220°C or higher during the setting process of the fabric. Since it may pass through high temperatures, the sewing thread itself is required to have dimensional stability at high temperatures. As a guideline, the dry heat shrinkage rate (H3) at 220'C can be adopted. In other words, the dry heat shrinkage rate at 220°C (
If H3) exceeds 8.0%, the dimensional stability at high temperatures will be poor and the seam appearance will become "unsightly", which is not preferable.

Furthermore, the sewing thread of the present invention has an untwisting torque (T) of 20T.
/m or less, so no snarls occur during use, making it extremely easy to handle.Also, the single yarn denier of the polyphenylene sulfide yarn constituting the sewing thread of the present invention is 2 to 10 deniers, preferably 3 to 10 deniers. It is 7 denier. 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. In other words, if the single yarn denier is less than 2 denier, yarn breakage, single yarn breakage, and fluff will occur frequently during the spinning and drawing process, and furthermore, single yarn breakage and fluff will occur during the subsequent twisting and setting process. This is because it occurs frequently. Polyphenylene sulfide fiber has a lower Young's modulus and is softer than polyethylene terephthalate fiber, which is the most commonly used synthetic fiber. However, if the single yarn denier exceeds 10 denier, the sewing thread becomes stiff and difficult to bend, making it difficult to make neat seams. This is not desirable because it will not be possible to do so.

In order to manufacture sewing thread having the above characteristics, it is important to employ the following manufacturing method, and this manufacturing method will be described in detail.

The polyphenylene sulfide used in the present invention can be obtained by a known synthesis method, for example, by reacting anhydrous sodium sulfide with a polyhalogen-substituted aromatic compound in a polar organic solvent.
It is a polymer composed of 0% or more of 1@-8+. Of course, the degree of polymerization of the polymer is less than 10%.In addition, from the viewpoint of spinning/drawability and productivity, the degree of polymerization of the polymer is set at a temperature of 320°C and a shear rate (?) of 10005ec-1, and a melt viscosity of 700 to 700.
Linear polyphenylene sulfide equivalent to 1200 poise is preferred. If the melt viscosity is less than 700 poise,
Since the degree of polymerization is low, sewing thread with sufficient mechanical properties cannot be obtained. When the melt viscosity exceeds 1200 poise, the degree of polymerization is too high, so the spinning speed does not increase, which is unfavorable in terms of productivity, and the mechanical properties do not necessarily improve dramatically, so there is no advantage.

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. For this purpose, it is important to set the spinneret surface temperature to 310 to 330°C during spinning. When the spindle surface temperature is less than 310°C, the spindle temperature is too low, and the physical properties of the raw yarn (drawn yarn) are insufficient, and the spinning is difficult.

During stretching, single yarn breakage increases and productivity decreases. For this reason, fluff and yarn breakage occur during the production of sewing thread, which is undesirable, and the physical properties of the obtained sewing thread are also insufficient.

On the other hand, if the die surface temperature exceeds 330° C., the temperature is too high, the coloring of the fibers progresses, 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 300 to 800 m/min. Spinning speed is 1
If it exceeds 000 m/min, there are disadvantages such as (il) the strength of the drawn yarn obtained is not sufficient, (ii) single yarn breakage occurs frequently during the drawing process, and (ii1 fuzz is likely to occur).

In addition, when the spinning speed is 300 m/min without groove, the productivity becomes low.

Here, the spinning equipment has a spinning temperature of 340 to 350'.
Existing equipment used for polyester can be used as is, as long as it is capable of spinning at a high temperature of about C. However, in the present invention, optimization of the spinneret temperature leads to high productivity and
Since it is important to satisfy high properties, it is necessary to insert a temperature detection end into the spinneret surface and control the spinneret surface temperature by adjusting the spinning temperature and the temperature around the spinneret surface.

Next is the stretching/heat treatment operation, in the present invention,
The stretching heat treatment is not carried out at once, but at -degrees, 150'
After oriented crystallization by stretching at a temperature below 150
A method of heat treatment at a temperature of .degree. C. or higher is preferred. Also, the stretching speed is not necessarily limited, and may be a normal stretching speed,
For example, a speed of about 100 to 800 m/min may be adopted.

The raw yarn (drawn yarn) obtained in this way has a strength of 4
g/de or more, the silk factor is 20 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 3000 to 12000. At this time, when the twist coefficient is less than 3000,
The convergence of the sewing thread becomes insufficient, and the sewing thread tends to separate into single fibers on the surface of the fabric during sewing, which is undesirable.

On the other hand, when the twist coefficient (K) exceeds 12000, m
This is not preferable because the internal strain of the fiber becomes large and the strength decreases greatly.

Next, it is necessary to heat set the twisted multifilament to stop the untwisting torque. In the case of polyethylene terephthalate, the purpose can normally be achieved in wet or dry heat at temperatures below 130"C, but in the case of polyphenylene sulfide II, the torque does not decrease at this temperature, and the untwisting torque is extremely low. It is large, has many snarls, and is extremely difficult to handle.Therefore, it is necessary to set it at a higher temperature, which requires a temperature of at least 140°C.Specifically, the surface temperature is 160°C.
This can be easily carried out by using a roller heated to the above temperature.

Next, a plurality of the above-mentioned twisted multifilaments are combined and given a ply twist. The direction of the first twist is opposite to the direction of the first twist, and usually the first twist is an S twist, and the first twist is a Z twist. In the production of normal sewing thread, the number of top twists is 7 of the number of bottom twists.
A range of 0 to 90% is used. This condition can also be adopted for sewing thread made of polyphenylene nalphide fiber, and the twist coefficient (K) is preferably in the range of 3,000 to 15,000. This was set from the perspective of reducing torque; for example, when the twist coefficient is less than 3000 (lower twist: S direction, upper twist: Z direction), the torque in the Z direction becomes large, and when it exceeds 15000, the torque in the Z direction becomes large. Since the torque in the S direction becomes large, the untwisting torque becomes 20 T/m or more even if set at a high temperature, and the handleability as a sewing thread deteriorates, which is not preferable.

Next, the setting temperature for ply twisting is preferably 180° C. or higher.

When the setting temperature is less than 180℃, the twisting effect is sufficient and the untwisting torque is 20T/m or more, and the dimensional stability as sewing thread (especially at high temperatures) is insufficient.
For example, the dry heat shrinkage rate at 220° C. exceeds 8.0%, which is undesirable.

Incidentally, in the setting method for the first twist, it is easy to use a heated roller whose surface roller temperature is 180° C. or higher, preferably 200° C. or higher, as in the first twisting method. In addition, it is more preferable that the untwisting torque of the sewing thread is 10 T/m or less. In addition, in order to improve the smoothness of the ply-twisted set yarn as a sewing thread, it is coated with a lubricant consisting of silicone oil and mineral oil.
It is preferable to add up to 5% (weight of fiber N).

(Effects) Polyphenylene sulfide is a polymer with excellent heat resistance and chemical resistance, and there have been many reports on its fiberization. However, no specific reports have been made so far regarding practical sewing threads and manufacturing methods. This is due to the fact that the polymer level as a textile grade is lower than that of ordinary synthetic fibers, such as polyester and nylon, and that fibers, especially multi-IIi
There is also the problem that the yarn spinning technology for fiberization has not necessarily been established, and furthermore, polyphenylene sulfide itself is prone to wear and single yarn breakage and fluffing are likely to occur.Furthermore, there are no reports on the twist setting technology. This was because the above-mentioned practical sewing thread and its manufacturing technology had not been established. In this sense, the sewing machine of the present invention and its manufacturing method have extremely great industrial significance.

However, according to the present invention, ■ strength of 3.0 g/de or more,
Excellent mechanical properties with a silk factor of 18 or higher.

■It has excellent dimensional stability with a dry heat shrinkage rate of 8.0% or less at 220℃, and ■Single yarn denier is 2 to 10.
It is possible to industrially and stably produce sewing thread made of polyphenylene sulfide fiber, which is thin in denier, (1) has excellent handling properties with an untwisting torque of 20 T/m or less, and (2) has good heat and humidity resistance and chemical resistance.

(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) Using a normal tensile tester, measure the stress °-elongation curve at room temperature 25°C, humidity 60%, sample length 20 cm, and tensile speed 200 mm/min. The elongation at the point where the stress is maximum (F
l) was read. Moreover, the value obtained by dividing the maximum stress by the fineness of the sample was defined as the strength (St).

(2) Dry heat shrinkage rate at 220°C A multifilament "skein" was made and treated in a dryer set at 180°C for 30 minutes under no load, and the shrinkage rate was determined from the following formula.

j! o 1+ Shrinkage rate (%) = -x 1o.

(3) Silk factor (SF) Silk factor (SF) was calculated from the following formula using the values of strength (St) and elongation (El) calculated in (1).

5F=Sj (g/de)

(5) Occurrence status of fluff 9 The surface of the sewing thread was visually observed and qualitatively evaluated.

(6) Untwisting torque (T/m> Apply a load equivalent to 1 mcI/de to the looped yarn and leave it until the load stops. (Hang the load and wait.) Next, calculate the number of twists at this time. Measure.

The number of twists was measured using an Asano Kikai II twister with a sample length of 50 cm, and was converted to T/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 = Engineering x F intoxication Examples 1 to 3. Comparative Examples 1 to 10 Polyphenylene sulfide dried in a hot air dryer at 180°C for 4 hours (temperature 320°C2 shear rate 103'
34 chips with a melt viscosity of 970 boids at 5ec-1
Melts at 0℃, hole diameter 0.35φ, land length 0.70mm
It was extruded from a spinneret equipped with 100 round holes.

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/100 fil after stretching. Subsequently, the extruded polymer stream was cooled and solidified, applied with an oil agent, and then rolled up.

Next, the obtained undrawn yarn was heated to a surface temperature of 100 °C and 1
The film was stretched between rollers at 20°C, then heat treated using rollers whose surface roller temperature was 210°C, and then rolled up at a speed of 350 m/min through cooling rollers. In addition, 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/100fil was first twisted with S, and then it was twisted with a high temperature roller (speed 100m/
It was heat-treated for 1 minute) and rolled up through a cooling roller. Next, pull three of these together and make 600 de/300f.
t+, Z ply-twisted, then heat treated with a high speed roller (speed 100 m/min), cooled with a cooling roller, applied with a silicone oil (3 wt% based on the weight of the fiber), rolled up, and sewn with a sewing machine. I made it into a 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 Comparative Example 1, since the die temperature was low, there were many yarn breakages and single yarn breakages during the spinning and drawing steps, and there were many yarn breakages during the subsequent ply twisting and final twisting. Furthermore, the mechanical properties were insufficient and there was a lot of fuzz.

Examples 1 to 3 are examples of the present invention, and had excellent mechanical properties as sewing threads and good dimensional stability. In addition, in terms of quality, there was no fuzz and a good appearance was observed. Furthermore,
The process passability during production was also extremely good.

In Comparative Example 2, the spinneret temperature during spinning was too high, so the degree of coloring of the discharged fibers was large, and there was room for improvement in the process conditions during spinning and drawing and yarn breakage when applying first twist and first twist. Moreover, the quality was also inadequate.

In Comparative Example 3, the spinning speed was too high, so it was not possible to obtain sewing thread with excellent mechanical properties.

In addition, process passability was extremely poor, and there was a lot of fluff of sewing thread.

In Comparative Examples 4 and 5, the set temperature for the first twist was low and the twist fixing properties were extremely poor, so during the final twist, there were many yarn breaks at the guide due to snarls, and there was also a lot of fuzz.

In Comparative Example 6, 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 breakage occurred frequently. Also, there was a lot of fluff.

In Comparative Example 7, the twist in the first twist was too large, the strength of the sewing thread was low, and the untwisting torque was large, resulting in poor handling.

Comparative Example 8 lacked ply-twisting, and Comparative Example 9 had too much ply-twisting, resulting in an imbalance between S twist and 7-twisting, extremely high untwisting torque, and extremely poor handling.

In Comparative Example 10, the setting temperature after ply-twisting was low, so 220
The dry heat shrinkage rate of 'C was high and the dimensional stability at high temperatures was insufficient. Furthermore, the twist-preventing properties were insufficient and the handling properties were also not good.

Incidentally, the occurrence of fuzz and yarn breakage described in the present invention is based on the following definitions.

[Fuzz condition] Can be attached.

[Occurrence of yarn breakage] Next, using the ring twisting machine at a speed of 20 m/min, 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 2500 rpm, no cutting of the sewing thread occurred during 3 minutes. Furthermore, the sewability was good, and skipped stitches hardly occurred.

Subsequently, the sewing thread of Example 2 was tested for heat and humidity resistance, alkali resistance, and acid resistance. As a comparison,
Sewing thread made of polyphenylene isophthalamide fiber (600 de/300 fil, with a first twist coefficient of 8,800 and a second twist coefficient of 10,500) was used.

Claims (2)

[Claims] (1) A polyphenylene sulfide which is characterized in that the constituent polymer is substantially polyphenylene sulfide and also satisfies the following requirements [1] to [4] at the same time in a sewing thread that has been given a top twist and a first twist. Sewing thread made of fiber. [1] The strength (St) of the sewing thread is 3.0 g/de or more, and the silk factor (SF) is 18 or more. [Silk factor (SF) is the sewing thread strength (St)
and the elongation (El) of the sewing thread, as determined by the following formula. SF=St(g/de)×√[El(%)]][2]2
The dry heat shrinkage rate (HS) at 20°C is 8.0% or less. [3] The single yarn denier of the polyphenylene sulfide 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) linear polyphenylene sulfide in which 85% or more of the repeating units are phenylene sulfide is melted, spun at a spinneret temperature of 310 to 330°C and a spinning speed of 1000 m/min or less, and then subjected to drawing heat treatment to form a drawn yarn;
A method for producing sewing thread made of polyphenylene sulfide fiber, which comprises 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 140
An operation in which twist setting is performed at a temperature above ℃. [2] A plurality of multifilaments obtained by the operation of [1] are twisted together to give a twist coefficient (K) of 3,000 to 15,000, and then twisted at a temperature of 180°C or higher and below the melting point. , An operation of setting the twist stop so that the untwisting torque (T) is 20 T/m or less. [The twist coefficient (K) is calculated from the number of twists (T) and the denier (D) of the multifilament to be twisted, using the following formula. K=T×√D〕