JPS62215071A - Polybutylene terephthalate crimped yarn and its production - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a polybutylene terephthalate crimped yarn and a method for producing the same.

<Prior art> Conventionally, crimped yarns made of polyester, polyamide, etc. are bulky,
Although it is widely used in the production of stretch woven and knitted fabrics, in recent years there has been a strong demand for higher quality and lower cost crimped yarns. Therefore, there is a strong desire for a crimped yarn that has high elasticity and is free from trouble in the weaving and knitting fabric manufacturing process. For example, it is a crimped yarn that does not cause multifilament single yarn breakage or scum generation.

However, in recent years, with the diversification of products, higher speeds in the production of crimped yarn, higher speeds in the production of woven and knitted fabrics, in order to lower prices,
Due to process simplification, single thread breakage of multifilament,
The occurrence of scum tends to increase, and many solutions have been proposed, but no satisfactory solution has yet been found. Similar problems exist in polybutylene terephthalate crimped yarns. Polybutylene terephthalate crimped yarn has excellent stretch performance and color clarity that polybutylene terephthalate crimped yarn does not have.

Since it has an excellent feel that polyamide crimped yarn does not have, there is a strong desire to solve the above problem.

Purpose of the present invention Among the above-mentioned problems, it is an object of the present invention to provide a polybutylene terephthalate crimped yarn and a method for manufacturing the same, which do not cause scum to occur during the production of woven or knitted fabrics.

The inventors of the present invention conducted intensive studies to obtain crimped polybutylene terephthalate yarns that do not generate scum during the production of woven or knitted fabrics, and found that the amount of scum generated depends on the pH of the lubricant attached to the crimped polybutylene terephthalate yarns. After discovering something significant, and conducting further research, we arrived at the present invention.

Structure and operation> In other words, the present invention provides the following features: (1) An oil agent is deposited in a range of 0.2 to 3.0% based on the weight of the yarn, and the pH of the oil agent attached to the yarn is 6.2 or more. Crimp of polybutylene terephthalate characterized by (2) pH of the oil emulsion applied during spinning is set to 7.5 or more, and the emulsion is applied to the spun polybutylene terephthalate yarn, and then stretched and false twisted. The main content is a method for producing polybutylene terephthalate crimped yarn.

In the present invention, polybutylene terephthalate is used.

It is necessary that the oil agent application rate to the cotton thread be in the range of 0.2 to 3.0%.

If it is less than 0.062%, the oil coating on the yarn becomes uneven, the oil coating becomes thin, and abnormal tension occurs during the production of woven or knitted fabrics.

Damage to the yarn and even scum will occur. On the other hand, if this adhesion rate exceeds 3.0%, oil scattering occurs due to the oil retention limit of the yarn, so it is necessary to keep it below 3.0%, more preferably below 2.5%.

The most characteristic feature of the present invention is that the pH of the polybutylene terephthalate crimped thread-imparting oil agent is maintained at 6.2 or higher. This point will be explained in more detail with reference to the accompanying drawings.

In Fig. 1, the amount of scum generated decreases as the pH of the applied oil increases, but it decreases particularly significantly at pH 6.0 to 6.1, and the stable tlH range that does not cause any problems in use is more preferably 6.2 or higher. is 6.3 or more.

The reason why scum generation is drastically reduced by increasing the pH of the applied oil to 6.2 or higher is still not fully understood, but according to the research of the present inventors, increasing the l' Improvement in the compatibility of smoothing agents, emulsifiers, and antistatic agents in non-aqueous conditions has not been confirmed. Therefore, it is presumed that by setting the DI to 16.2 or higher, the compatibility between the oil components on the polybutylene terephthalate crimped yarn is good, thereby suppressing the generation of scum. On the other hand, the upper limit of the pH of the applied oil is not limited in terms of scum generation, but if it is too high, problems such as deterioration of polybutylene terephthalate or mold growth of the applied oil will occur, so it is at most 9.0, more preferably 8. It is better to set it to .0 or less.

There are some things to keep in mind when setting the discharge 1 of the oil agent adhering to the polybutylene terephthalate crimped yarn to 6.2 or more, which is a feature of the present invention. It is the E)H of the spinning oil emulsion that is 7.
．． Adjust it to 5 or more.

FIG. 2 shows the relationship between pl-1 of the spinning oil emulsion and the pH of the oil adhering to the yarn. The pH of the spinning oil emulsion and the pH of the yarn oil are positively correlated, and in order to obtain l) H6,2 or higher of the oil adhering to the yarn, the pH of the spinning oil emulsion must be 7.5 or higher.

Polybutylene terephthalate as used in the present invention refers to polybutylene terephthalate containing 70% by weight or more, and 30% by weight or less of other polymers such as polyethylene terephthalate and polyamide.

It may contain a copolymer, a heat stabilizer, an antioxidant, a matting agent, etc.

In order to maintain the oil application rate on the yarn within the range of 0.3 to 3.0%, an oil emulsion of 0.3 to 3.0% is added as a spinning oil after polybutylene terephthalate melt spinning and before winding.
The most common and easiest method is to apply a crimped yarn oil such that the amount is 0%, but a non-aqueous oil may also be used, and a step of applying a crimped yarn oil may also be used. In this case, there are no particular restrictions on the oil composition and oil components, and those commonly used in this field may be used.

When an oil application step is used after the crimping process, the C1 application rate is 0.3 to 3.0% for the entire oil deposited on the yarn.

The pH may be adjusted to 6.2 or higher.

The manufacturing process of the polybutylene terephthalate crimped yarn of the present invention is: ■ A process in which spinning, drawing, and false twisting are independent ■ A process in which spinning and drawing and false twisting are independent ■ A process in which spinning and drawing and false twisting are independent ■ Any continuous process of spinning, drawing, false twisting can be adopted, and an oil application process may be added either singly or continuously after false twisting.

Here, the spinning process consists of low-oriented undrawn yarn by low-speed take-up,
Either a highly oriented undrawn yarn spinning process by high-speed take-off or a so-called partially oriented yarn spinning process may be used.

Note that the stretch rate of the polybutylene terephthalate crimped yarn in the present invention is not particularly limited, and for applications that require high stretchability, crimped yarns with a high stretch rate may be used, while crimped yarns with low stretchability may be used. A crimped yarn with a low elasticity may be used.

In the present invention, the oil adhesion rate, the pH of the pl-1° spinning oil emulsion of the adhering oil, and the amount of scum generated are measured by the following methods.

(ω Oil adhesion rate 3 g of polybutylene terephthalate crimped yarn is extracted with cyclohexane for 30 minutes using a Soxhlet extraction group, the cyclohexane in the extract is evaporated, and the residual oil type f
fi (W) was measured, and the oil adhesion rate (%) = (W/
3”) x 100.

(b+ pH of attached oil agent) Polybutylene terephthalate crimped thread 209 was stirred in distilled water of 5009 at 40°C for 30 minutes to extract the oil agent, and the oil agent extract was naturally cooled to 20°C.
M-7 type 1) Measure with an H meter.

(e) pH of the spinning oil emulsion The oil emulsion is measured at 20° C. using a Hitachi-Horiba Model M-7 1) H meter.

(d+ Scum generation amount Polybutylene terephthalate crimped yarn at 20℃, 65% R
The supply tension was adjusted to 0.5 g/de for the sample prepared for 2 days at H, and the same sample was run for 120 minutes on a chrome matte guide with a diameter of 4 ms+ and a roughness of 5S at a contact angle of 90 degrees and a take-up speed of 7007 FL/min. Repeat 5 times with scum on the guide @
Measure the mouth (unit η).

[Example] Example-1 Polybutylene terephthalate having an intrinsic viscosity [η] of 0.88 and containing 0.1% by weight of titanium oxide was melted at 265°C using a spinneret having 6 holes of 0.3φ. Discharge ff
i Dispense at 5.1g/min and take-up speed 1000711
The yarn was taken off at a speed of 1/min, applied with a spinning oil, and then wound to obtain an undrawn yarn.

The spinning oil used at this time was mainly composed of a smoothing agent, an emulsifier, and a stimulant (Table 2), and was mixed with ion-exchanged water to a total concentration of 1.
．． It was a 5% emulsion, and the emulsion I) was used with various changes in caustic soda or lactic acid. The amount of spinning oil applied is such that the oil adhesion rate after crimping is 0.55 to 0.
It was adjusted to be 6%.

The undrawn yarn was then drawn 2.3 times at a rate of 5007 FL/min, and was continuously heated to a Shore hardness of 9 at a heater temperature of 190°C.
A 20 denier/6 filament crimped yarn was obtained by false twisting using a 3° urethane shaft circumscribed friction false twisting device.

Table 1 shows the amount of scum generated in the obtained crimped yarn.

Table 1 Table 2 Smoothing agent Isostearate ester of lauryl alcohol (4 moles of Eo added)...10% Emulsifier Nonylphenyl (added 9 moles of EO) Needle...10
Weight% Lauryl (10 moles of EO added) Ether...10weight% Antistatic agent Na metal salt of alkyl sulfate...5mm% Metal soap...5% by weight Example-
2 Crimped yarn test No. 2, 4, 5°6 obtained in Example-1.
8 was subjected to a stocking knitting test using a KT-4 type stocking knitting machine manufactured by Mizuta Kikai Co., Ltd. at 600 rpa+.

As a result, the crimped yarn according to the present invention (Test No. 5.6.8)
), no scum adhesion to the knitting needles was observed even after continuous knitting for 24 hours, and the knitted fabric was in good condition with no stitch breaks, skipped stitches, single-row irregularities, warp lines, etc.

On the other hand, with the crimped yarn other than the present invention (Test No. 2), scum adhesion to the knitting needles was observed after 6 hours, and at the same time, warp lines were generated in the knitted fabric. Also, for test No. 4, 188
After some time had passed, the same problem as Test No. 2 occurred.

[Brief explanation of drawings]

Figure 1 is a graph showing the relationship between the adhering oil pH and the maximum scum generation for polybutylene terephthalate crimped yarn.
The figure is also a graph showing the relationship between the pH of the spinning oil emulsion and the pH of the adhering oil. Engraving of the drawings (no changes to the content) Figure 1 Tsumegami I 1 Shi Yuki IPH Figure 2 Disruption of the disturbance Emma J Reg 3 pH Procedural amendment (c) 1. Special display of the incident! 1Irt Showa 61-53575 No. 2, Title of the invention

Claims (3)

[Claims] (1) An oil agent is attached to the yarn in a range of 0.2 to 3.0% based on the weight of the yarn, and the pH of the oil agent attached to the yarn is 6.2.
A polybutylene terephthalate crimped yarn characterized by the above. (2) The polybutylene terephthalate crimped yarn according to claim (1), wherein the pH of the oil adhering to the yarn is 9.0 or less. (3) The pH of the oil emulsion applied during spinning is set to 7.5 or higher, and 0.3 to 3.0% of the oil emulsion is applied to the spun polybutylene terephthalate yarn, and then stretched and false-twisted. A method for producing polybutylene terephthalate crimped yarn.