JPH08134723A - Biodegradable conjugate fiber - Google Patents

Abstract

PURPOSE: To easily obtain a biodegradable conjugate fiber controllable in biodegradability and the extent of dyeability, designed to alternately arrange two kinds of biodegradable polymer components differing in crystallization rate from each other so as to expose them onto the fiber surface. CONSTITUTION: This conjugate fiber is made up of two kinds of biodegradable polymer components A, B differing in crystallization rate from each other and designed to alternately arrange them on the fiber cross section, continue them along the fiber axis and expose them onto the fiber surface. The highly crystalline polymer component is low in biodegradation rate and poor in dyeability, while the low-crystalline polymer component is good in biodegradability and dyeability, and owing to the two components' exposure onto the fiber surface, the objective fiber excellent in producibility, blodegradability and dyeability can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biodegradable conjugate fiber which can be produced with good spinnability and can be made into fibers having different degrees of biodegradability and dyeability.

[0002]

2. Description of the Related Art Conventionally, when a biodegradable fiber is produced by a melt spinning method, a method in which a spun filament is cooled and solidified by blowing a cooling air and then drawn is adopted.

However, many polymers having excellent biodegradability have a crystallization temperature lower than room temperature and a slow crystallization rate, and the spun yarn is insufficiently cooled only by ordinary cooling air blowing. Therefore, it could not be solidified and blocking occurred.

As a solution to this problem, it is conceivable to lower the cooling air temperature, lengthen the cooling time, or increase the cooling air velocity. However, the method of lowering the cooling air temperature still fails to achieve sufficient cooling, and there is a device limitation in increasing the cooling time. There was a problem of close contact.

Although various biodegradable polymers have been proposed, fibers having different degrees of biodegradability and dyeability are desired depending on the use.

[0006]

DISCLOSURE OF THE INVENTION The present invention comprises a biodegradable polymer having a low crystallization temperature and a slow crystallization rate,
An object of the present invention is to provide a biodegradable conjugate fiber that can be produced with good spinnability and that can obtain fibers having different degrees of biodegradability and dyeability.

[0007]

Means for Solving the Problems The present invention is to solve the above-mentioned problems, and the gist thereof is a composite fiber composed of component A and component B having biodegradability and different crystallization rates. The component A and the component B are alternately arranged in the fiber cross section, both of which are continuous in the fiber axis direction and are exposed on the fiber surface, and are alternately arrayed biodegradable conjugate fibers. It is in.

The present invention will be described in detail below.

As the component A, the molar ratio is 100/0 to 90/10.
Range of polybutylene succinate (PBS) and polyethylene succinate (PES), polybutylene adipate (PBA) or polybutylene sebacate (PBSe)
Copolymers with and are preferably used.

As the component B, the molar ratio is 85/15 to 65.
/ 35, preferably in the range 85/15 to 70/30 PBS and PE
A copolymer with S, PBA or PBSe is preferably used.

If the proportion of PBS as the component A is less than the above range, the spinnability is poor, and if the proportion of PBS as the component B is more than the above range, the biodegradability and dyeability are poor, and if it is too small, the heat resistance and the obtained fiber are low. The thread quality performance is inferior.

These polymers have a number average molecular weight of 200
A value of at least 00, preferably at least 30,000, is desirable in terms of spinnability and properties of the obtained fiber.

It is desirable that the polymer to be used for spinning contains 0.01 to 5% by weight, preferably 0.05 to 2% by weight, of an inorganic crystal nucleating agent such as calcium carbonate, titanium dioxide, alumina, silica and talc.

The melt spinning temperature varies depending on the melting point and molecular weight of the polymer used, but it is preferably 150 to 280 ° C. If the spinning temperature is less than 150 ° C, melt extrusion is difficult, and if it exceeds 280 ° C, the polymer is remarkably decomposed, and it becomes difficult to obtain high-strength fibers.

It is necessary that the components A and B are alternately arranged in the fiber cross section, and that both are continuous in the fiber axis direction and are exposed on the fiber surface. Among biodegradable polymers, generally, a polymer with good crystallinity has a property of slow decomposition rate and poor dyeability, while a polymer with low crystallinity has properties of excellent dyeability and biodegradability. are doing. When a polymer having a good crystallinity such as the component A is used for a single-type or core-sheath type sheath, the entire fiber surface is covered with it, so blocking can be prevented, but biodegradability and dyeability are poor. However, when a polymer having low crystallinity such as the component B is used, blocking occurs and the spinnability deteriorates. Therefore, by exposing both components to the surface of the fiber, it becomes possible to obtain a fiber having excellent spinnability, biodegradability and dyeability.

The total number of arrangements of the component A and the component B is preferably 12 or more. When the number of arrays is small, the area occupied on the surface of one row of fibers is large, and sufficient cooling performance,
The biodegradability and dyeing performance cannot be obtained. Further, by changing the number of arrangements, it becomes possible to obtain fibers having different performances.

The composite weight ratio of component A and component B is from 1/1 to
It is preferably 3/1. When component A is more than the above range, biodegradability and dyeability are inferior, and when it is less, blocking is likely to occur and the spinnability is deteriorated. Furthermore, by changing the composite ratio, it becomes possible to obtain fibers having different performances.

The melt-spun yarn is cooled by an annular or horizontal spraying installed directly below the spinneret. The yarn that has been solidified by cooling is 300 to 3500 m after applying the spinning oil.
The film is drawn at a speed of 1 / minute and is continuously drawn after being wound or without being wound. As the spinning oil agent, a conventional spinning oil agent for polyester fibers can be used.

The stretching is carried out at room temperature or in a single stage or in multiple stages using a heat roller or the like. In order to obtain a high-strength fiber, it is desirable to draw in multiple stages, and a hot plate or a hot oven may be used between the heating roller and the drawing roller during the second drawing step. Particularly, when dimensional stability is required, it is desirable to add a constant length heat treatment or a relaxation heat treatment subsequent to the stretching. In this way, it is possible to manufacture an alternating array type conjugate fiber having a certain yarn quality performance, biodegradability and dyeability that can be practically used.

[0020]

EXAMPLES Next, the present invention will be specifically described by way of examples. The measurement and evaluation methods are as follows. Tensile strength and elongation Measured according to JIS L 1013. Biodegradability For 3 months from July to October, after burying the sample in the soil, take it out and measure the strength. If the strength retention rate is less than 50%, it is evaluated as ○, and if it is 50% or more, it is evaluated as △. did. Dyeability Resolin Blue (Disperse dye manufactured by Bayer) was used at 1% owf, dyed at 70 ° C for 15 minutes at a bath ratio of 1/100, and PBS 100%
Compared as a control, good ones ○,
Those with little difference were evaluated as Δ.

Example 1 As the component A, PBS having a number average molecular weight of 40,000 was used, and as the component B, a copolymer of PBS and PES having a molar ratio of 80/20 was added with 0.1% by weight of titanium dioxide. Supplied to extruder type melt spinning machine, spinning temperature 170 ℃
Then, in the fiber cross section, the component A and the component B are melt-spun from a spinneret, which is a fiber having an array number of 12 alternately arranged in a radial pattern, cooled and solidified by horizontal spraying, and after adding an aqueous emulsion oil agent, 400 m / Pick up at the speed of a minute,
Continuous 1st stage draw ratio of 1.5 times, 2nd stage draw ratio
Stretching at 2.7 times and total stretching ratio of about 4.1, 315d / 36f
An alternating array type composite fiber was obtained.

Examples 2 to 4 and Comparative Examples 1 to 8 Under the conditions shown in Table 1, yarn was produced in the same manner as in Example 1. Table 1 shows the characteristic values of the composite fibers obtained in Examples 1 to 4 and Comparative Examples 1 to 8.

[0023]

[Table 1]

In Examples 1 to 4, there was no blocking between filaments, and composite fibers having good characteristics were obtained. In Comparative Examples 2 to 5 and 7 to 8, blocking occurred between filaments, and Comparative Examples In Nos. 1 and 6, only those having poor biodegradability and dyeability were obtained.

[0025]

EFFECTS OF THE INVENTION According to the present invention, there is provided a biodegradable conjugate fiber which can be produced with good spinnability and can be made into fibers having different degrees of biodegradability and dyeability.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenji Yamada 23, Uji Kozakura, Uji City, Kyoto Prefecture Unitika Research Institute, Central Research Laboratory (72) Inventor Shiritsu Murase, 23, Uji Kozakura, Uji City, Kyoto Unitika Stock Company Central Research In-house

Claims (3)

[Claims] 1. A composite fiber comprising component A and component B which are biodegradable and have different crystallization rates, wherein component A
And the component B are alternately arranged in the fiber cross section, and both are continuous in the fiber axis direction and are exposed on the fiber surface, an alternating array type biodegradable conjugate fiber. 2. Component A is a copolymer of polybutylene succinate and polyethylene succinate, polybutylene adipate or polybutylene sebacate in a molar ratio of 100/0 to 90/10, and component B is a molar ratio. 85/15 ~ 65/35
The biodegradable conjugate fiber according to claim 1, which is a copolymer of polybutylene succinate and polyethylene succinate, polybutylene adipate, or polybutylene sebacate in the range. 3. The total number of arrangements of the component A and the component B is 12 or more, and the composite weight ratio of the component A and the component B is 1/1 to 3 /.
The biodegradable conjugate fiber according to claim 1 or 2, which is 1.