JP2002212830A - Biodegradable polyester fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biodegradable polyester fiber having improved mechanical characteristics, excellent flexibility, available with good yarn manufacturing properties, capable of substantially retaining quality during the period of use, rapidly carrying out degradation even under the natural environment by disposal after the use, and further providing a fertilizer which is a positive nutrient source for soil. SOLUTION: This biodegradable polyester fiber comprises a polymer containing at least one kind of the nutrient salt in a polymer having biodegradability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biodegradable polyester fiber which has improved mechanical performance, can control the rate of biodegradability, and can be a positive nutrient source for soil after disposal. .

[0002]

2. Description of the Related Art In recent years, from the viewpoint of protection of the natural environment, biodegradable polymers that can be decomposed in the natural environment and molded articles thereof have been demanded. Biodegradable polymers such as aliphatic polyesters have been actively studied. ing. Among them, polylactic acid-based polymers are particularly expected to be resources because they use agricultural products as raw materials, are excellent in melt moldability and heat resistance, and have mechanical properties. ing.

However, the polylactic acid-based polymer has a high glass transition temperature, and the fiber made of this polymer has a drawback of being inferior in flexibility and being hard, and it has been desired to improve this drawback. In addition, there is a problem that the decomposability rate in the natural environment is slow, the disposal period is long, and a less widely used disposal method such as a compost method or an activated sludge method has to be applied.

[0004] As means for improving the flexibility of the fiber, it is possible to copolymerize a polylactic acid-based polymer with a different component,
It is known to mix or combine with other materials. In this case, although the flexibility and the biodegradation rate are somewhat improved, there are problems in the mechanical properties such as a problem in the spinning property, a low strength, and a high hot water shrinkage. . In addition, a material that is more flexible and has a higher decomposition rate is required. Furthermore, these conventional materials do not become effective fertilizers for soil and the like, and improvements in this respect have been desired.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, improves mechanical properties,
It has excellent flexibility and good yarn-making properties, maintains quality substantially during use, and can be quickly decomposed in the natural environment when disposed of after use. An object of the present invention is to provide a biodegradable polyester fiber that can be a source of fertilizer.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, have reached the present invention. That is, the gist of the present invention is a biodegradable polyester fiber comprising a polymer in which at least one nutrient salt is contained in a polymer having biodegradability.

[0007]

Next, the present invention will be described in detail. The fiber of the present invention is composed of a biodegradable polymer, and examples of such a polymer include generally known aliphatic polyesters. As the aliphatic polyester, (1) glycolic acid, lactic acid, hydroxyalkyl carboxylic acid such as hydroxybutyl carboxylic acid,
(2) aliphatic lactones such as glycolide, lactide, butyrolactone, and caprolactone; (3) aliphatic diols such as ethylene glycol, propylene glycol, and butanediol; (4) diethylene glycol, triethylene glycol, ethylene / propylene glycol, dihydroxyethyl butane Oligomers of polypolyalkylene ethers such as polyalkylene glycols such as polyethylene glycol, polypropylene glycol and polybutylene ether; (5) polyalkylenes such as polypropylene carbonate, polybutylene carbonate, polyhexane carbonate, polyoctane carbonate, polydecane carbonate, etc. Carbonate glycols and their oligomers, (6) succinic acid, adipic acid,
Main component (70% by mass or more) derived from aliphatic polyester polymerization raw materials such as suberic acid, azelaic acid, sebacic acid, and aliphatic dicarboxylic acid such as decanedicarboxylic acid
Wherein the aliphatic polyester block and / or random copolymer, and the aliphatic polyester are mixed with other components such as aromatic polyester, polyether, polycarbonate, polyamide, polyurethane, polyorganosiloxane and the like in an amount of 30% by mass. % (Block or random) copolymer and / or a mixture thereof.

In the present invention, the melting point of the biodegradable polymer as described above is preferably 100 ° C. or higher, more preferably 120 ° C. or higher, further preferably 140 ° C. or higher from the viewpoint of heat resistance. Among the above-mentioned aliphatic polyesters, polylactic acid derived from lactic acid has the highest melting point. Therefore, it is preferable to use a polylactic acid-based polymer.

The polylactic acid is mainly composed of a polymer of an optical isomer by L-lactic acid and D-lactic acid or a blend thereof. Optical purity of both L-lactic acid and D-lactic acid is 0
If the optical purity is inferior in the presence of ％ 100%, the melting point and the heat resistance tend to decrease, and the heat shrinkage properties tend to be too large. Therefore, in the present invention,
Preferably, the optical purity is 90% or more.

A copolymer obtained by copolymerizing comonomers such as hydroxycarboxylic acids and lactones to the extent that the performance of the lactic acid-based polymer is not impaired may be used. Examples of the copolymerizable hydroxycarboxylic acids and lactones include glycolic acid, 3-hydroxy encholic acid, 4-hydroxy encholic acid,
4-hydroxyvaleric acid, hydroxycaproic acid, glycolide, β-propiolactone, β-butyrolactone, ε
-Caprolactone and the like.

[0011] These lactic acid polymers can be produced by polymerizing lactic acid by a conventionally known method. Examples of the polymerization method, for example, a method of directly dehydrating and condensing lactic acid,
A method in which lactide, which is a cyclic dimer of lactic acid, is obtained by ring-opening polymerization is exemplified. These polymerization reactions may be carried out in a solvent, and if necessary, the reaction may be carried out efficiently using a catalyst or an initiator. These methods may be appropriately selected in consideration of necessary molecular weight and melt viscosity.

The melt viscosity of the biodegradable polymer forming the fiber of the present invention is preferably set to a melt flow rate (hereinafter, referred to as MFR) value of 0.2 to 100 g / 10 minutes. If the MFR is less than 0.2 g / 10 min, the processability tends to decrease, while if it exceeds 100 g / 10 min, mechanical properties and the like tend not to be sufficiently exhibited. Therefore, the MFR
The value is more preferably from 1.0 to 50 g / 10 minutes, still more preferably from 3.0 to 30 g / 10 minutes, and most preferably from 5.0 to 20 g / 10 minutes. Note that the MFR value is ASTM-D-1238E
Means the value measured according to the method of

The biodegradable polymer in the present invention is a biodegradable polymer such as the above-mentioned aliphatic polyester containing at least one nutrient. In the present invention, a plurality of biodegradable polymers (such as aliphatic polyesters) as described above may be blended. The term "nutrient salt preparation" as used in the present invention refers to a salt necessary for the normal growth of an organism, and refers to an inorganic substance that becomes a nutrient for phytoplankton and algae. Examples of the nutrient include salts of phosphoric acid, nitric acid, sulfuric acid, silicic acid and the like. In these nutrients, basic ions or acidic ions are interposed in the polymer composition due to the influence of moisture, and the hydrolysis of the polymer component proceeds under the influence of these ions, resulting in a lower level. It will proceed to molecular weight reduction.

More specifically, these nutrient salts may be exemplified by calcium phosphate, potassium phosphate,
Trisodium phosphate, ammonium phosphate, magnesium phosphate and the like can be mentioned, and as the nitric acid type salt, calcium nitrate, ammonium nitrate, sodium nitrate, potassium nitrate and the like can be mentioned. In addition, ammonium sulfate,
Examples include magnesium sulfate, manganese sulfate, and potassium sulfate.

Regarding silicates, most of the rocks on the earth
Are silicates, of which orthosilicate ions SiO_Four
^----And Mg⁺⁺, Fe⁺⁺Olivine with Mg (Mg, Fe²)_TwoSiO_TwoAnd
SiO_Three―― with pyroxene (touki stone) CaMg (SiO_Three)_Two, Si_FourO₁₁ ⁶―
Amphibolite (geumite) Ca with _TwoMg_Five(Si_FourO₁₁)_Two(OH)_TwoPassing
And Si_TwoO_Five ^-With mica KAl_Two(AlSi_ThreeO_Ten) (OH)_TwoEtc.
It is.

Other salts include potassium chloride, calcium carbonate, magnesium oxide, magnesium borate and the like, and these can also be used as nutrients.

The polymer in the present invention contains at least one kind of the above-mentioned nutrient salt, and if necessary, contains two or more kinds. As a particularly preferable example, it is preferable to include a plurality of types of compound fertilizer components by selecting a substance accompanying nitrogen, phosphoric acid, and potassium, which are the three major nutrients of soil, in a well-balanced manner. Also, depending on the properties of the soil, calcareous fertilizer, siliceous fertilizer, mafic fertilizer,
The nutrient salt corresponding to the manganese fertilizer or the boron fertilizer may be appropriately selected according to the purpose.

The nutrient salt in the polymer acts as a cushion with the polymer and improves flexibility. It also affects the biodegradability rate, and the higher the content of the nutrient, the higher the decomposition rate, and the biodegradability can be controlled by the type and content of the nutrient used. If the content of the nutrient is too small, the mechanical properties such as flexibility are not improved and do not contribute to the decomposition rate. If the content is too large, the strength is reduced and the cost is problematic. Therefore, the content of the nutrient in the biodegradable polymer (total content when a plurality of nutrients are used) is preferably 0.1%.
It is 5 to 30% by mass, more preferably 3 to 25% by mass, and most preferably 5 to 20% by mass.

The form of these nutrient salts is preferably in the form of a powder. The maximum particle size of the powder is 5 μm or less, more preferably 3 μm or less.
It is good to be below μm. If the maximum particle size of the powder is too large, pressure rises on the screen during spinning, resulting in reduced operability and defects in fibers and other products. Therefore, when the powder shape is large, it is good to carry out a pulverizing process in advance, and since the form of the nutrient salt greatly contributes to the operability and quality stability related to fiber production, the powder should be as fine as possible. Is good.

The biodegradable polyester fiber of the present invention is made of a biodegradable polymer containing a nutrient as described above, but it is important that the fiber is oriented. The reason for this is that the orientation of the crystals can maintain fiber strength and suppress heat shrinkage, and can achieve dimensional stability of the fiber or a product using the fiber.

Therefore, the biodegradable polyester fiber of the present invention has a strength of 2 cN / dtex or more, a hot water shrinkage of 15% or less,
Further, it is preferable that the bending rigidity is 20 cN or less. If the strength is less than 2 cN / dtex, yarn breakage occurs during knitting or weaving, and a knitting step or a weaving step is apt to occur. The higher the strength, the more the practical range is widened and can be applied to general-purpose applications, which is preferable. However, at present, the upper limit is about 6.5 cN / dtex. Therefore, it is preferably at least 2 cN / dtex, more preferably at least 2.5 cN / dtex, further preferably at least 3 cN / dtex.
It is at least N / dtex, most preferably at least 3.5 cN / dtex.

The elongation of the fiber is not particularly limited.
25-40% is preferred. When the elongation is less than 25%,
There is a problem that yarn breakage occurs and yarn operability decreases. On the other hand, if the elongation is too low, microvoids are likely to occur in the fiber, which may cause problems such as spots in the length direction of the yarn. On the other hand, if the elongation exceeds 40%, the dimensional stability during or after ordinary fabric formation may be reduced, so that it is generally difficult to use the fabric.

Next, the hot water shrinkage of the fiber of the present invention is 15%.
The following is preferred. The hot water shrinkage rate is an index that causes a product using the fiber to shrink or deteriorate under the influence of hot water or the like, that is, an index indicating dimensional stability. If the hot water shrinkage ratio exceeds 15%, shrinkage becomes too large, resulting in a problem of lack of dimensional stability and a rough feeling, resulting in a decrease in flexibility. Since the lower the hot water shrinkage ratio, the better the dimensional stability, more preferably 13% or less,
More preferably, it is set to 10% or less.

Further, the fiber of the present invention has a flexural rigidity of 20.
It is preferably not more than cN. This value is an index indicating flexibility, and was measured by the following method. interval
2 with a diameter of 1 mm placed horizontally in parallel with a distance of 5 mm
A 15 mm long measuring object (together with a total fineness of 5000 dtex) was set on a stainless steel rod, a hook with a diameter of 1 mm was hooked at the center, and the two stainless steel rods were pulled out. The maximum stress (cN) at the time was measured. The pulling speed for moving the hook is 5 mm / min.
Atmospheric conditions during the measurement were set at 20 ° C. and 65% RH. The filament of the object to be measured is 20 ° C and 65% RH in advance.
The sample was left for 24 hours or more in the atmosphere described above, and then subjected to measurement.

The smaller the bending stiffness is, the more excellent the flexibility is. It is more preferably 18 cN or less, further preferably 15 cN or less. Flexural rigidity is 20
If it exceeds cN, the fiber becomes hard, and feel and handling deteriorate.

The biodegradable polyester fiber of the present invention is composed of a biodegradable polymer containing a nutrient salt as described above, but may be a composite fiber composed of a plurality of biodegradable polymers. In this case, at least one polymer may be a biodegradable polymer containing a nutrient salt. However, it is preferable to satisfy the above physical properties.

The single fiber fineness of the biodegradable polyester fiber of the present invention is 0.5 to 10 in the case of multifilament.
In the case of a decitex or a monofilament, it is preferably at least 10 decitex. The flexibility is more preferable because the smaller the single fiber fineness, the better.However, when the fiber density is less than 0.5 dtex, when forming the fiber, the solidification point is controlled, the accuracy of the die hole is increased, the productivity is reduced due to the decrease in the discharge amount, the yarn It is not preferable because an increase in the number of cuts becomes a problem. Also,
If the single-filament fineness is too large, depending on the application, there may be a problem that the flexibility of the fiber or fabric (woven or knitted fabric, non-woven fabric) is reduced. This is difficult, and requires special production equipment, which increases costs, which is not preferable.

The fibers of the present invention may be not only long fibers, but also short fibers which are formed by forming a drawn tow and then crimped with a crimper to arbitrarily cut the fibers.

The cross-sectional shape of the fiber is not particularly limited, and examples thereof include various cross-sectional shapes such as a round cross-section, an irregular cross-section, and a hollow cross-section. In the case of a composite fiber composed of two or more polymers, the composite fiber may have a cross-sectional shape such as a core-sheath type, a side-by-side type, a sea-island type, a radial split type, a point symmetric split type, or a multilayer type. Also,
In the composite spinning, the nutrient salt component may be arranged to be exposed on the fiber surface or may be arranged to be present inside the fiber.

Further, the fiber of the present invention may be used alone or in combination with the same or different kinds of fibers, and can be used for producing a knitted fabric, a woven fabric, a nonwoven fabric, a composite material or other structures. When mixed with other fibers, synthetic fibers composed of fiber-forming polymers such as polyester fibers, nylon fibers, acrylic fibers, vinylon fibers, polypropylene fibers, polyethylene fibers, regenerated fibers such as rayon, and semi-synthetic materials such as acetate Fibers and natural fibers such as wool, silk, cotton, and hemp are employed.
Among them, it is more preferable to mix with biodegradable fibers such as regenerated fiber, semi-synthetic fiber, natural fiber, and fiber made of aliphatic polyester, since a biodegradable product is obtained.

The biodegradable fiber of the present invention may be modified variously by adding additives to the biodegradable polymer. Examples of secondary additives include:
Heat stabilizers, pigments, UV absorbers, antioxidants, antibacterials,
Lubricants, antistatic agents, release agents, crystal nucleating agents, softening agents, light-fast agents,
Examples include weathering agents, surfactants, plasticizers, surface modifiers, fragrances, dyes, flame retardants, matting agents, various inorganic or organic electrolytes, and the like.

Next, a method for producing the biodegradable polyester fiber of the present invention will be described. First, in the nutrient salt,
Since some of them contain water of crystallization, it is preferable to use them after drying (100 ° C. or more) for dehydration. The nutrient salt can be contained in the polymer by conventional means. The mixing method and the mixing apparatus are not particularly limited, but those capable of continuously performing the metering and mixing process are preferable industrially and in terms of quality. For example, a weighed amount of a nutrient salt may be dry-blended onto a polymer chip and melted by a single-screw extruder or a twin-screw kneading extruder. Then, the polymer in the molten state may be spun immediately.

Further, a nutrient salt agent, which has been weighed in advance, is melt-kneaded with a biaxial kneading extruder or the like, spun into a strand shape, cooled, cut and cut into a master batch as a chip. To manufacture. The masterbatch and the polymer to be used are separately melted, mixed at a predetermined ratio in a static mixer and / or a dynamic mixer, and may be immediately spun, or may be formed into chips and then melt-spun. . Further, the masterbatch and the polymer to be used may be supplied to a jet color measuring and mixing apparatus, and may be melt-mixed together with an extruder or the like and spinning may be performed.

In the melt-mixing method, polymer deterioration, quality,
It is necessary to substantially prevent copolymerization by transesterification, and it is preferable to mix and spin at a temperature as low as possible and within a short time. That is, the temperature is preferably 230 ° C. or lower, more preferably 210 ° C. or lower, more preferably 200 ° C. or lower. The time is preferably mixed within 30 minutes, more preferably within 20 minutes, even more preferably within 10 minutes.

At the time of spinning, the above-mentioned dry blending method,
Although it is useful to apply a metering mixing method with a master batch using a jet color, spinning may be performed by mixing with a static mixer in a spinneret after individual melting and metering by a composite spinning device.

The spun fiber yarn is provided with an oil agent after cooling, and the fiber can be obtained by a two-step method of once winding and then drawing, or a one-step method of continuing drawing without winding. As the stretching conditions, the stretching temperature is preferably equal to or higher than the glass transition temperature of the fiber and equal to or lower than (melting point −10) ° C., and it is preferable to perform multi-stage thermal stretching. As a heat treatment condition at the time of stretching or after the stretching, the heat treatment temperature is preferably (melting point−10) ° C. or more and (melting point−30) ° C. or less.

[0037]

Next, the present invention will be specifically described based on examples. The measurement and evaluation of various characteristics in the examples were performed by the following methods. (1) Glass transition temperature and melting point (° C.) of polymer: Initial extreme values of melting and absorption curves measured at a heating rate of 20 ° C./min using a differential scanning calorimeter DSC-2 manufactured by PerkinElmer. The temperature that gives the extreme value is the glass transition temperature (Tg) and the melting point (Tg).
m). (2) MFR [melt viscosity (g / 10 minutes)]: Measured by the method described above. (3) Yarn-forming properties: The following evaluations were conducted in the fiber manufacturing process including spinning and drawing. 〇: The operating condition is good and there is no problem at all. Δ: Thread breakage occurred once or twice / 2 hours, and there was a slight problem. X: Thread breakage occurred 3 times or more / 2 hours, resulting in poor operability. (4) Strong elongation: According to JIS L-1013, using an Autograph S-100 manufactured by Shimadzu Corporation, gripping interval 25c
m and a tensile speed of 30 cm / min. (5) Hot water shrinkage: According to JIS L-1013 hot water shrinkage A method, the shrinkage after treatment for 15 minutes under boiling water was measured. (6) Flexibility (flexural rigidity): The flexural rigidity was measured by the method described above. (7) Biodegradability: Koike Seisakusho knitting machine (MODEL: CR-B,
The fiber obtained by using 16G stitches: 180) is knitted in a tube to prepare a sample piece of a tube knitted fabric of 5 cm × 10 cm. This sample piece was buried in the soil outdoors at a depth of 10 cm from the ground surface. This sample piece was dug out after 12 months, visually observed, and evaluated according to the following four grades. ×: No change at all Δ: Whitened 〇: Shape partially collapsed. A: Almost collapsed.

[Preparation of Master Chips (A1 to A8)]
As nutrients, nutrients previously dried as shown in Table 1 were prepared, and the following three types of polymers were used. That is, the glass transition temperature is 62 ° C., the melting point is 168 ° C., and the MFR is
Is 15 g / 10 minutes, poly L-lactic acid resin (B1), glass transition temperature is 42 ° C., melting point is 165 ° C., MFR is 20 g / min.
Poly L-lactic acid copolymer resin (B2) having 1.5 mol of hydroxycarboxylic acid copolymerized for 10 minutes, butanediol and succinic acid having a glass transition temperature of -32 ° C, a melting point of 115 ° C, and an MFR of 30 g / 10 minutes. Used was a polybutylene succinate resin (C1) obtained by polymerization in an equimolar amount. Dry blending of the weighed nutrients on the polymer chips
The mixture was melt-kneaded at a temperature of 200 ° C. and a residence time of 8.5 minutes by using a kneading extruder kneader with a shaft, and was spun into a strand shape from two holes of a die head. After cooling the obtained strand, it was cut to obtain master chips (A1 to A8) shown in Table 1.

[0039]

【table 1】

Examples 1 to 5 Poly L-lactic acid resin having an optical purity of 98.8%, a glass transition temperature of 73 ° C., a melting point of 169 ° C., and an MFR of 25 g / 10 min (hereinafter referred to as resin D1). The master chips (A1, A2, A4 to A6) shown in Table 1 were variously changed as shown in Table 2 and individually mixed and mixed such that the nutrient content was 5% by mass. Melted by a mold extruder, spinning temperature 210 ° C, single hole discharge rate 1.35g /
Then, the mixture was melt-spun from a spinneret having a round hole. Next, the spun yarn was cooled with a cooling device, and a spinning oil agent was applied in an appropriate amount, and then wound at a spinning speed of 1200 m / min. Continued
First roller temperature 1 using a commonly used hot stretching machine
00 ° C, heater plate temperature 130 ° C, second roller temperature 130 ° C, stretching ratio 3.8, stretching speed 500m /
It was wound up in minutes to obtain a fiber of 107 dtex and 36 filaments. The thermal contact time of the yarn between the heater plate and the second roller was 0.8 seconds. Table 2 shows the physical property values and evaluation results of the obtained polylactic acid-based long fibers.

[0041]

[Table 2]

As is evident from Table 2, the fibers of Examples 1 to 5 had practical mechanical performance, were excellent in flexibility and biodegradability, and could be obtained with good spinning properties.

Examples 6 to 9 and Comparative Example 1 Except that the resin D1 and the master chip (A3) shown in Table 1 were individually weighed and mixed so as to have a nutrient content as shown in Table 3, In the same manner as in Example 1, a fiber having 107 dtex and 36 filaments was obtained. Table 3 shows the physical property values and evaluation results of the obtained polylactic acid-based long fibers.

[0044]

[Table 3]

As is evident from Table 3, the fibers of Examples 6 to 9 had practical mechanical performance, were excellent in flexibility and biodegradability, and could be obtained with good spinning properties. Then, with the increase in the content of the nutrient, the flexibility and the biodegradability were improved, and it was found that the decomposition rate could be controlled by the content of the nutrient. On the other hand, the fiber of Comparative Example 1
Since it was made of a polylactic acid-based polymer containing no nutrient salt, it had a high hot water shrinkage, poor flexibility, and poor biodegradability.

Example 10 B3 (poly L-lactic acid copolymer resin) and a master chip (A
7), using a composite type spinning apparatus composed of two extruders, individually melting and weighing, and then having a hole diameter of 0.3 mm from the spinneret having four stages of a sluzer type static mixer in the spinneret apparatus. The fiber was spun from the hole. The spinning conditions were as follows: spinning temperature: 210 ° C., single-hole discharge rate: 1.35 g / min (B3 single-hole discharge rate: 1.01 g / min, A1 single-hole discharge rate: 0.34 g / min)
Min) and the spinning speed was 3000 m / min. Then, the film was drawn at a roller temperature of 130 ° C. to a draw ratio of 1.25 and wound up to obtain a fiber of 108 dtex and 30 filaments. Table 4 shows the physical property values and evaluation results of the obtained polylactic acid-based long fibers.

Example 11 The procedure of Example 10 was repeated, except that C1 (polybutylene succinate resin) and the master chip (A8) were used, to obtain a fiber of 108 decitex and 30 filaments. Table 4 shows the physical property values and evaluation results of the obtained polylactic acid-based long fibers.

Example 12 B3 (poly L-lactic acid copolymer resin) and a master chip (A
7), and a mixture obtained by blending both with a jet color mixer (the mixing weight ratio of A7 and B3 is 1: 9) is supplied to one extruder of a composite spinning apparatus, and melted and measured at a temperature of 210 ° C. The ingredients. C1 (polybutylene succinate resin) and master chip (A8)
And a mixture obtained by weighing both with a jet color mixer (mixing weight ratio of A8 and C1 is 1: 9) is supplied to the other extruder of the composite spinning apparatus, and the temperature is adjusted to 20.
It was melted and weighed at 0 ° C. to obtain a core component. The individually weighed polymer of the core-sheath component is composite-spun into a core-sheath type using a composite spinneret at a temperature of 210 ° C., and after cooling, an oil agent is applied to produce a spinning speed of 12%.
The film was wound at a speed of 00 m / min. The core-sheath composite ratio (weight ratio) was 1: 1 and the single hole discharge rate was 2.5 g / min. Subsequently, the temperature of the first roller was set to 100 ° C., the temperature of the heater plate was set to 130 ° C., and the temperature of the second roller was set to 130 ° C. using a commonly used thermal stretching machine, and the stretching ratio was 3.5 and the stretching speed was 50
Winding was performed at 0 m / min to obtain a fiber of 111 detex 36 filaments. The contact time of the yarn between the heater plate and the second roller was 0.8 seconds. Table 4 shows the physical property values and evaluation results of the obtained polylactic acid-based long fibers.

Example 13 B3 (poly L-lactic acid copolymer resin) and a master chip (A
6), a mixture obtained by weighing and blending them with a jet color mixer (the mixing weight ratio of A6 and B3 is 3: 7) is supplied to one extruder of a composite spinning apparatus, and melted and weighed at a temperature of 210 ° C. The ingredients. In addition, C1 (polybutylene succinate resin) and master chip (A7)
And a mixture obtained by weighing the two with a jet color mixer (mixing weight ratio of A7 and C1 is 3: 7) is supplied to the other extruder of the composite spinning apparatus and the temperature is adjusted to 20.
It was melted and weighed at 0 ° C to obtain a sheath component. The individually weighed polymer of the core-sheath component is composite-spun into a core-sheath type using a composite spinneret at a temperature of 210 ° C., and after cooling, an oil agent is applied to produce a spinning speed of 12%.
The film was wound at a speed of 00 m / min. The core / sheath composite ratio was 1: 1 and the single hole discharge rate was 1.3 g / min. Subsequently, drawing was performed in the same manner as in Example 12 to obtain fibers of 111 decitex and 36 filaments. Table 4 shows the physical property values and evaluation results of the obtained polylactic acid-based long fibers.

Example 14 Glass transition temperature: -45 ° C., melting point: 105 ° C., MFR: 30 g
/ 10 min butanediol and succinic acid and adipic acid
The components of the polybutylene succinate / adipate copolymer resin (D2) copolymerized at a ratio of 100/80/20 and the master chip (A8) (the mixing weight ratio of A8 and D2 is 7:
3) was used as a sea component, and a component (mixing weight ratio of A8 and C1 was 7: 3) of C1 (polybutylene succinate resin) and the master chip (A8) was weighed and mixed as in Example 13; It was melted and measured individually at 200 ° C to obtain island components. Spinning was carried out at a temperature of 200 ° C. using a sea-island composite spinneret which became eight island components, and was wound at a speed of 1200 m / min. The sea-island composite ratio (weight) was 1: 1 and the single hole discharge rate was 1.35 g / min. Subsequently, the first roller temperature was set to 60 ° C., the heater plate temperature was set to 90 ° C., and the second roller temperature was set to 90 ° C. using a commonly used hot stretching machine, and the film was wound at a stretching ratio of 3.7 and a stretching speed of 500 m / min. A fiber of 110 decitex 36 filaments was obtained. The contact time of the yarn between the heater plate and the second roller was 0.8 seconds. Table 4 shows the performance of the obtained polylactic acid-based long fibers.

[0051]

[Table 4]

As apparent from Table 4, Examples 10 to 1
The fiber of No. 4 had practical mechanical performance, was excellent in flexibility and biodegradability, and could be obtained with good spinning properties. Then, with the increase in the content of the nutrient, the flexibility and the biodegradability were improved, and it was found that the decomposition rate could be controlled by the content of the nutrient.

[0053]

According to the present invention, the biodegradable polyester fiber is
Has practical mechanical performance, excellent flexibility, and
It is possible to control the rate of degradability when disposing of used ones, it can be an active nutrient source when returning to soil, and it can contribute to the growth of plants as a safe fertilizer. is there. And the fiber of the present invention is knitted, woven,
It can be formed into non-woven fabric, paper, felt, net, rope, etc., and can be more suitably used for agricultural and forestry industries.

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Claims (5)

[Claims] 1. A biodegradable polyester fiber comprising a polymer having at least one nutrient in a polymer having biodegradability. 2. The polymer having biodegradability has a melting point of 10
The biodegradable polyester fiber according to claim 1, which is at least 0 ° C. 3. The biodegradable polyester fiber according to claim 1, wherein the polymer having biodegradability is a lactic acid-based polymer. 4. The nutrient salt is a phosphoric acid, nitric acid, sulfuric acid or silicic acid salt, and the content of the nutrient in the polymer is 0.5%.
The biodegradable polyester fiber according to claim 1, 2 or 3, wherein the amount is from 30 to 30% by mass. 5. A strength of 2 cN / dtex or more and a hot water shrinkage of 15
%, And the bending rigidity is 20 cN or less.
The biodegradable polyester fiber according to 2, 3, or 4.