JPS584090B2 - Polyester fabric - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyester fiber made of polytetramethylene terephthalate and a method for producing the same.

Heretofore, fibers made from polyesters comprising tetramethylene terephthalate units, ie, polytetramethylene terephthalate polymers, have been expected to be used, for example, in coarse yarns and carpet yarns because of their excellent tensile elastic recovery properties.

However, the polytetramethylene terephthalate fiber has an initial modulus that is approximately the same as that of the polyamide fiber currently used for this purpose, and in order to make it more versatile than polyamide fiber, mechanical properties such as It is necessary to improve the initial modulus.

The present invention was achieved as a result of intensive research from the fiber structure aspect in order to further improve the initial modulus of the above-mentioned polytetramethylene terephthalate fiber.

That is, the present invention provides (1) a polyester fiber consisting essentially of tetramethylene terephthalate with a crystal size of 30 to 43 Å and an initial modulus of 500 kg/mm2 or more; (2) an intrinsic viscosity [η] of 0.6 to 1.6 polytetramethylene terephthalate is spun at a spinning temperature of 260 to 290°C and a spinning speed of 1100 m/min or higher, and then the resulting undrawn yarn is stretched to a drawing ratio of 3 without substantially applying heat.
2. The method for producing a polyester fiber according to item 1, wherein the polyester fiber is stretched by rollers at a stretching speed of 500 m/min or more.

In the present invention, the term "polyester consisting essentially of tetramethylene terephthalate rods" means a linear polyester obtained by condensing 1,4-butanediol and terephthalic acid, and one of the above alcohol components and acid components.
A copolymer mainly composed of polytetramethylene terephthalate in which 5 molar proportion or less is replaced with other copolymerizable components, or the above polytetramethylene terephthalate 85w
It may be a mixture of t% or more and less than 15wt% of other organic polymer substances.

Furthermore, these linear polyesters can be used even if organic or inorganic substances such as flame retardants, pigments, and fillers are added thereto.

Furthermore, in the present invention, "crystal size" is a value representing the size in a direction substantially perpendicular to the fiber axis of the crystal, and is determined by the following X-ray diffraction method.

That is, if the meridional direction diffraction intensity at the plug reflection angle 2θ = 17.1 is Iam, and the 010 plane reflection peak intensity is It, then the peak width B of the 010 plane reflection peak at an intensity of (lt + Iam)/2 (expressed in radians) From this, the crystal size L is calculated using the Schierer formula (
In the previous equation, b=o. o0204 radians, K=0.9
4, λ=1, 542 people).

The same X-ray diffraction was carried out using a D-9C device manufactured by Rigaku Denki Co., Ltd., and the measurement conditions were 35KV x 20mA, Ni filter used, divergence slit 0.15mmφ, scattering slit 1°, receiving slit O. 4m
Let it be m.

Further, the initial modulus is calculated using the following formula by performing a tensile test using an Instron tensile tester under the conditions of a sample length of 20 cr and a tensile rate of 20% per minute, reading the strength at an elongation rate of 1 or more within the elastic limit.

For polytetramethylene terephthalate fibers having an initial modulus of 500 kg/mm3 or more, the crystal size must be 30 to 43.

When the crystal size is less than 30X, the crystal growth is small and the microstructure is immature, so the initial modulus is 500 kc.
If the crystal size is smaller than g/mm2 and the crystal size is 43λ or more, the fine structure will be too dense and the initial modulus will actually fall below 500 kg/mm3.

Therefore, in order to obtain a high initial modulus of 500 kq/mi3 or more, it is necessary that the crystal size is within the range of 30 to 43 crystals.

Polytetramethylene terephthalate fibers having the above-mentioned crystal size and initial modulus have a strength of 3.5-5. Og
/de, elongation 20-45% boiling water shrinkage 12-20%, 5
It exhibits extremely good performance with a tensile elasticity recovery rate of 95 to 100 inches, and when further processed, it is extremely useful as a coarse yarn or carpet yarn.

The novel polyester fiber of the present invention is produced by the following method.

That is, the normal intrinsic viscosity [η) (measured at 350°C in C-chlorophenol) is 0.6 to 1.6, preferably 0.8.
-1.2 polytetramethylene terephthalate is spun at a spinning humidity of 260 to 290°C and a spinning speed of 1100 m/min or more.

If the spinning temperature is less than 260°C, the humidity will be too low, resulting in poor spinnability and easy yarn breakage.

If the temperature exceeds 290°C, [η] decreases so much that the strength of the drawn yarn becomes low and cannot be put to practical use.

Furthermore, if the spinning speed is less than 1100 m/min, the wound undrawn yarn will self-extend, resulting in failure to unwind the undrawn yarn package.

40 when considering mechanical factors (winding machine performance) and economic efficiency.
It is preferable to set it to 00 m/min or less.

Next, the obtained undrawn yarn is roller-stretched at a stretching ratio of 3 times or less and a stretching speed of 500 m/min or more without substantially applying heat.

Since polytetramethylene terephthalate is easily crystallized, it is necessary to draw it without applying substantial heat.

Hot stretching (for example, stretching using heated rollers) promotes crystallization, fixes the microstructure, and lowers the initial modulus.

Furthermore, if the stretching ratio exceeds 3 times, stretching yarn breakage is likely to occur, making stretching virtually impossible.

Preferably it is 1.1 to 2.8 times.

Furthermore, what is particularly important in the present invention is that 500m/m
The goal is to stretch at a speed of 1.5 in or more.

By drawing at such a high speed, the undrawn yarn can be greatly deformed in a short period of time, and the structure of the drawn yarn can be made loose.

At an ungrooved stretching speed of 500 m/min, the crystal size is 4.
3λ and the initial modulus is less than 500 kg/mm3.

Then, the undrawn yarn is heated at such a high speed (>500 m
/min), a method using a stretching pin is inappropriate, and it is necessary to use a roller and wind the film several times around the roller for stretching.

The drawing pin can be wound only once at most, and the drawing point is not fixed, resulting in uneven drawing, and the resulting drawn yarn has a crystal size of 3.
Something outside the range of 0 to 43 occurs.

As described above, according to the present invention, it is possible to obtain a polytetramethylene terephthalate yarn having a crystal size of 30 to 43 and an initial modulus of 500 kg/mm2 or more, which is not only useful as yarn, hojaly yarn or carpet yarn, but also It also has many industrial effects such as low manufacturing cost.

The present invention will be specifically explained below with reference to Examples.

Example 1 A polytetramethylene terephthalate polymer having an intrinsic viscosity of 0.86 was discharged at the spinning temperature shown below, the yarn was cooled, coated with oil, and then wound up at the spinning speed shown below.

Next, the undrawn yarn was wound eight times around a 90-itφ chamber roller, stretched to the following ratio, and wound at a stretching speed of 500 m/min.

The performance of the obtained yarn is shown in Table 1.

Comparative Example 1 Example 1 Experiment No. Example 1 except that the undrawn yarn of No. 3 was wound 8 times around a 90 mmφ roll heated to 50°C.
Similarly, the performance of the drawn yarn (Experiment No. 10) is as follows.

Strength - 4.4g/de: Elongation - 34%: Crystal size = 4
7 Å = initial modulus = 280 kg/mm3: 5% elongation elastic recovery rate - 96 coefficient Comparative Example 2 Example 1 Experiment No. The performance of the yarn (Experiment No. 11), which was drawn in the same manner as in Example 1 except that the undrawn yarn of No. 3 was wound once around a 1.3 miφ cold pin, was as follows.

Strength = 3.9g/de: Elongation -2.1%: Crystal size =
4.51: Initial modulus = 320k9/mm3: 5%
Elongation elastic recovery rate = 98% Example 2 After spinning polytetramethylene terephthalate polymer with an intrinsic viscosity of 1.15 at a spinning temperature of 280°C, the yarn was cooled, oil was applied, and the yarn was spun at 1500 m/min. I wound it up.

Next, the yarn was wound around a 90 mmφ roll 5 times, then stretched to the following ratio and wound at 550 m/win.

The performance of the obtained yarn is as shown in Table 2.Example 3 Example 1 Experiment No. The undrawn yarn of No. 3 was wound 8 times around a 90 mmφ chamber mixing roller, then stretched 2.2 times and wound at various stretching speeds.

The performance of the obtained drawn yarn is shown in Table 3.

Claims (1)

[Scope of Claims] 1. A polyester fiber consisting essentially of tetramethylene terephthalate units, having a crystal size of 30 to 43 Å and an initial modulus of 500 kg/mm2 or more. 2 Polytetramethylene terephthalate having an intrinsic viscosity [η] of 0.6 to 1.6 is spun at a spinning temperature of 260 to 290°C and a spinning speed of 1100 m/Lin or more, and then substantially heat is applied to the resulting undrawn yarn. 2. The method for producing polyester fibers according to claim 1, wherein the polyester fiber is stretched at a stretching ratio of 3 times or less and a stretching speed of 500 m/min or more.