JPH0881830A - Biodegradable composite crimped filament - Google Patents

Abstract

PURPOSE: To obtain a relatively inexpensive biodegradable crimped conjugate filament capable of being supplied to practical uses, having constant heat resistance and strength, and capable of being perfectly degraded in the nature. CONSTITUTION: The biodegradable crimped conjugate filament comprises eccentrically conjugated components which comprise the same composition selected from polybutylene succinate, polyethylene succinate or their copolymer and which have a different melt-flow rate of 10-45g/10min (measured at 190 deg.C under a load of 2.16kg according to JIS K7210) therebetween.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biodegradable composite crimped filament having excellent stretchability and bulkiness.

[0002]

2. Description of the Related Art Conventionally, fibers having excellent strength and weather resistance have been required as fibers for industrial materials used for fishing, agriculture and civil engineering, and mainly consist of polyamide, aromatic polyester, vinylon, polyolefin and the like. Things are being used. However, these fibers are not self-degradable, and there is a problem in that they cause various pollutions if left in the sea or mountains after use. This problem can be solved by incineration, landfilling, or recovery and recycling after use, but these processes require a great deal of expense.
Further, regarding the landfill, there is a problem that the material is chemically stable in a normal natural environment as described above, so that the material is kept in the original state for a long time in the soil.

As a method for solving such a problem, it is considered to use a biodegradable (microbiologically degradable or naturally degradable) material, and biodegradable fiber made of an aliphatic polyester is drawing attention.

For example, JP-A-5-59611 and JP-A-5-59611.
No. 59612 discloses a high strength filament made of polycaprolactone. However, since polycaprolactone has a low melting point of about 60 ° C., its fiber is
There was a problem that heat of 60 ° C or higher could not be applied in the processing step, crimping was difficult to occur, and heat resistance was poor.

Further, Japanese Patent Laid-Open No. 93317/1993 discloses a component A consisting of poly-ε-caprolactone and / or poly-β-propiolactone, poly-3-hydroxybutyrate and poly-3-hydroxyvalerate. A biodegradable conjugate fiber having a latent crimping ability, which is composed of a component B composed of a copolymer of However, the polymer of the component B has a problem that the yarn-forming property is slightly poor, and the composite fiber also has a slightly poor yarn-forming property.

[0006]

DISCLOSURE OF THE INVENTION The present invention is a biodegradable crimped composite filament which is relatively inexpensive and has a certain level of heat resistance and strength that can be put to practical use and is completely decomposed in the natural world. Is to provide.

[0007]

Means for Solving the Problems The present invention is to solve the above-mentioned problems, and the gist thereof is composed of polybutylene succinate, polyethylene succinate or a copolymer thereof, and having the same composition and melt flow rate. (JIS K 7210
According to the above, temperature is 190 ℃ and load is 2.16kg) 10-45g
The biodegradable composite crimped filament is characterized in that components differing by / 10 minutes are eccentrically combined.

The present invention will be described in detail below. The polybutylene succinate, polyethylene succinate or copolymers thereof in the present invention are required to have a high degree of polymerization, and those having a number average molecular weight of about 30,000 or more have a spinnability and a yarn obtained. It is preferable in terms of the characteristics. Further, it may be chain-extended with a diisocyanate compound or the like to increase the degree of polymerization.

In the present invention, a small amount of other thermoplastic biodegradable component can be added within the range that does not impair the basic characteristics of each component.

The copolymer composition of polybutylene succinate and polyethylene succinate has a molar ratio of 100/0 to
It is preferably in the range of 70/30 or 15/85 to 0/100. Outside this range, the melting point is low and the heat resistance is poor, such being undesirable.

The composite filament of the present invention is composed of components having the same composition selected from the above polymers but different melt viscosities. Melt flow rate (abbreviated as MF) is 5-40g
It is necessary to use a polymer of / 10 min and a polymer of MF of 15 to 50 g / 10 min so that the difference in MF between both components is 10 to 45 g / 10 min. If the difference in MF between the two components is less than 10 g / 10 min, the crimping performance will be poor. Conversely, if it exceeds 45 g / 10 min, yarn bending will occur during melt spinning and the spinnability will deteriorate.
Neither is preferred.

The composite filament of the present invention requires that both components are eccentrically combined, and specifically,
A side-by-side type or an eccentric core-sheath type composite form is adopted. The composite ratio of both components is suitably 1/5 to 5/1, preferably 2/3 to 3/2 by weight.

The single yarn fineness is preferably 0.5 to 10d. If the single yarn fineness is less than 0.5d, yarn bending is caused during melt spinning and the spinnability is poor, and if it exceeds 10d, the texture of the woven or knitted product becomes coarse and hard, which is not preferable.

The composite filament of the present invention can be efficiently produced by the following method.

That is, a high-viscosity polybutylene succinate, polyethylene succinate or a copolymer thereof is used as the component A, and a polymer having the same composition and a lower melt viscosity than that of the component A is used as the component B. Spin it. The spinning temperature varies depending on the composition and degree of polymerization of both components A and B,
Usually, it is 130-220 ℃. If the spinning temperature is less than 130 ° C, melt extrusion is difficult, and if it exceeds 220 ° C, thermal decomposition becomes remarkable, and it becomes difficult to obtain a high-strength filament.

The melt-spun yarn is air-cooled or water-cooled,
After being once wound or without being wound, it is subjected to one-stage or two-stage or more cold stretching or hot stretching.

The thus obtained composite filament of the present invention has crimps. The degree of crimp is
It can be adjusted by the type of polymer, composite ratio, draw ratio, temperature, etc., but in order to make a woven or knitted fabric with a soft texture that is excellent in stretchability and bulkiness, the number of crimps is 15/25 mm.
As described above, it is desirable that the crimping rate be 10% or more.

[0018]

The composite filament of the present invention is biodegradable because it is composed of biodegradable polybutylene succinate, polyethylene succinate or a copolymer thereof. Further, since the melt viscosity (MF) is different and the composition is composed of a component having a low glass transition point, a difference in shrinkage ratio (and a difference in heat shrinkage ratio) during stretch orientation causes
Spiral fine crimps are produced without special relaxation heat treatment.

[0019]

EXAMPLES Next, the present invention will be specifically described by way of examples. The measuring method and the evaluating method of each characteristic value are as follows. (1) Tensile strength and elongation Measured according to JIS L 1013. (2) Melting point (° C) The temperature that gives the maximum extremum of the melting endothermic curve obtained by measurement using a differential scanning calorimeter DSC-7 type manufactured by Perkin Elmer was taken as the melting point. (3) Number of crimps (pieces / 25 mm) According to JIS L 1015, the number of crimp peaks between 25 mm when a load of 2 mg / d was applied to a single yarn was measured. (4) Crimping ratio (%) Length a when a load of 2 mg / d is applied to a single yarn and 50 mg /
The length b when a load of d was applied was measured and calculated by the following formula. Crimping rate (%) = [(ba) / b] × 100 (5) Evaluation of biodegradability The sample was embedded in soil for 6 months, then taken out, and the tensile strength was measured and evaluated. When the tensile strength is reduced to 50% or less of the initial value, it is evaluated that the biodegradability is good.

Example 1 Number average molecular weight of about 49,000, melting point of 114 ° C., MF of 10 g /
10 minutes of polybutylene succinate as the component A, the same composition, number average molecular weight of about 31,000, melting point of 114 ℃, MF of 45
The polymer of g / 10 minutes is used as the B component, and the A component and the B component are supplied in a weight ratio of 1/1 to an extruder type melt spinning machine, and a side-by-side type composite spinning device is used at a spinning temperature of 200 ° C. After spinning from a 0.4 mmφ x 72-hole spinneret and cooling with a cooling air of 18 ° C, it was taken up by a take-up roller at a speed of 1300 m / min. The first stage drawing with a draw ratio of 1.5 times was performed, then the second stage drawing with a draw ratio of 1.1 times was performed between the first drawing roller and the heated second drawing roller at 80 ° C., and the film was relaxed and wound at room temperature. . The obtained multifilament is
The fineness was 225d / 72f, the tensile strength was 2.2g / d, and the elongation was 110%. Next, this multifilament was supplied to a stretching machine and stretched at a draw ratio of 2.2 times between a heating supply roller at 60 ° C. and a non-heating stretching roller. The obtained multifilament has a tensile strength of 3.2 g / d, an elongation of 42% and a crimp number of 17
The number was 25 / mm and the crimp rate was 14%. Further, when the crimped yarn was embedded in soil for 6 months and then taken out and the tensile strength was measured, it was found to be 44% or less of the initial value, indicating that the crimped yarn had good biodegradability.

Example 2 Number average molecular weight of about 47,000, melting point of 109 ° C., MF of 15 g /
A 10 minute polybutylene succinate / polyethylene succinate copolymer (molar ratio 90/10) was used as the component A, and the same composition had a number average molecular weight of about 34,000 and a melting point of 108.
Melt spinning was performed in the same manner as in Example 1 except that a polymer having a MF of 40 g / 10 ° C. and a MF of 40 g / 10 was used as the component B, stretched and wound.
The obtained multifilament has a fineness of 220d and a tensile strength.
The elongation was 2.0 g / d and the elongation was 117%. Then, this multifilament was supplied to a stretching machine and stretched in the same manner as in Example 1. The obtained multifilament has a tensile strength of 3.0 g / d, an elongation of 46%, a crimp number of 16/25 mm, and a crimp rate of 13
% Crimped yarn. Further, when this fiber was embedded in soil for 6 months and then taken out and the tensile strength was measured, it was found to be 37% or less of the initial value, indicating that it had good biodegradability.

Comparative Example 1 Number average molecular weight is about 44,000, melting point is 114 ° C., MF is 20 g /
10 minutes polybutylene succinate as the A component, the same composition, number average molecular weight of about 41,000, melting point 114 ℃, MF 27
Melt-spinning and drawing were performed in the same manner as in Example 1 except that the polymer of g / 10 min was used as the component B to obtain a multifilament. The obtained multifilament had a fineness of 225d, a tensile strength of 2.2g / d and an elongation of 100%. Then, this multifilament was supplied to a stretching machine and stretched in the same manner as in Example 1. The obtained multifilament had a crimp number of 9/25 mm and a crimp ratio of 7%, and was inferior in crimp performance.

Comparative Example 2 Number average molecular weight of about 51,000, melting point of 114 ° C., MF of 5 g /
10 minutes polybutylene succinate as the component A, the same composition, number average molecular weight of about 26,000, melting point 113 ℃, MF 55
Melt spinning was tried in the same manner as in Example 1 except that the polymer of g / 10 min was used as the component B. However, due to the bending of the melt spun yarn, sampling could not be performed and a multifilament could not be obtained.

Example 3 The same polymer as in Example 1 was used, the ratio of component A and component B was 3/2 by weight, and spinning was carried out at a spinning temperature of 200 ° C. using a spinneret of 0.4 mmφ × 24 holes. Then, after cooling with cooling air at 14 ° C., it was wound at a speed of 2800 m / min. The obtained multifilament has a fineness of 85d / 24f, a tensile strength of 2.8g / d,
The elongation was 138%. Next, this multifilament was supplied to a stretching machine and stretched at a draw ratio of 2.0 times between a heating supply roller at 60 ° C. and a non-heating stretching roller. The obtained multifilament has a tensile strength of 4.5 g / d and an elongation.
It was 51%, the number of crimps was 18/25 mm, and the crimp rate was 15%. Further, when the crimped yarn was embedded in soil for 6 months and then taken out and the tensile strength was measured, it was found to be 47% or less of the initial value, indicating that it had good biodegradability.

[0025]

According to the present invention, it is relatively inexpensive and
Has a certain level of heat resistance and strength that can be put to practical use,
A biodegradable crimped composite filament is provided that is completely degraded in nature. In addition, the composite filament of the present invention,
It has excellent crimping performance, and by using it, a biodegradable woven or knitted fabric having excellent stretchability and bulkiness can be obtained. Therefore, the composite filament of the present invention is suitable as a hygienic material or a life-related material.

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

Claims (1)

[Claims] 1. A polybutylene succinate, a polyethylene succinate, or a copolymer thereof, which has the same composition and melt flow rate (according to JIS K 7210, temperature
A biodegradable composite crimped filament characterized in that eccentric composites of components differing by 10 to 45 g / 10 minutes at 190 ° C. and a load of 2.16 kg).