JP2002173864A - Biodegradable filament nonwoven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ideal biodegradable filament nonwoven fabric effective for improving the mechanical properties such as the softness of the fiber without excessively deteriorating the crystallinity and heat-resistance, substantially keeping the quality during use, quickly decomposable even in natural environment by the disposal after use, useful as a fertilizer actively supplying the nutrients to the soil and producible at a low cost. SOLUTION: The bio-degradable filament nonwoven fabric is composed of a filament consisting of a biodegradable polymer having a melting point of >=100 deg.C and at least containing a nutrient salt agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biodegradable long-fiber nonwoven fabric that can improve the mechanical performance and control the biodegradation rate, and can be a positive nutrient source for soil after disposal. is there.

[0002]

2. Description of the Related Art In recent years, from the viewpoint of protecting the natural environment, products using a biodegradable polymer that degrades in the natural world have been demanded, and research on biodegradable polymers such as aliphatic polyesters has been actively conducted. . Among them, polylactic acid-based polymers are particularly advantageous in terms of resources because agricultural products are used as raw materials, are also excellent in melt moldability and heat resistance, and are most expected because they have mechanical properties. .

However, since the polylactic acid-based polymer has a high glass transition temperature, it is hard and inferior in flexibility when used as a fabric, and improvement of this drawback has been desired. In addition, since the decomposition rate in the natural environment is considerably slow, there is a problem that a disposal treatment period is long, and a method that is not widely used, such as a compost method or an activated sludge method, must be applied.

[0004] As a method for improving the flexibility of a fiber or fabric made of a polylactic acid-based polymer, it is known to copolymerize a polylactic acid-based polymer with a different component. However, in this method, although the flexibility and the biodegradation rate are somewhat improved, there is a problem in the yarn formability, and the resulting fiber or fabric has a low strength, and has a problem in mechanical properties.

[0005] Further, conventional biodegradable materials do not harm the natural world, but do not work effectively on the natural world.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to improve the mechanical properties such as flexibility of a fabric without excessively impairing the crystallinity and heat resistance, and to substantially improve the quality during use. It is an object of the present invention to provide an inexpensive biodegradable long-fiber nonwoven fabric that can be rapidly decomposed in a natural environment when disposed of after use and that can be applied to soil as a positive nutrient source, that is, a fertilizer.

[0007]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, have found that a biodegradable long-fiber nonwoven fabric described later achieves the object.

[0008] That is, the gist of the present invention is to provide a biodegradable long-fiber nonwoven fabric comprising a long fiber comprising a biodegradable polymer having a melting point of at least 100 ° C and containing at least a nutrient salt. Is what you do.

[0009]

Next, the present invention will be described in detail. The long fiber used in the present invention comprises a biodegradable polymer having a melting point of 100 ° C. or higher. As the biodegradable polymer, a generally known aliphatic polyester can be used.

Examples of the aliphatic polyester include (1) hydroxyalkyl carboxylic acids such as glycolic acid, lactic acid, and hydroxybutyl carboxylic acid; (2) aliphatic lactones such as glycolide, lactide, butyrolactone, and caprolactone; (3) ethylene glycol; Aliphatic diols such as propylene glycol and butanediol, (4) diethylene glycol, triethylene glycol, ethylene /
Propylene glycol, oligomers of polyalkylene ethers such as dihydroxyethylbutane, polyethylene glycol, polypropylene glycol, polyalkylene glycols such as polybutylene ether,
(5) Polyalkylene carbonate glycols such as polypropylene carbonate, polybutylene carbonate, polyhexane carbonate, polyoctane carbonate, polydecane carbonate, and oligomers thereof;
(6) Components mainly containing components derived from aliphatic polyester polymerization raw materials (70% by mass or more), such as aliphatic dicarboxylic acids such as succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, and decanedicarboxylic acid. And
Block copolymers and / or random copolymers of aliphatic polyesters and other components such as aromatic polyesters, polyethers, polycarbonates, polyamides, polyurethanes, polyorganosiloxanes, etc. are added to the aliphatic polyesters in a block copolymer content of 30% by mass or less. Those obtained by polymerization or random copolymerization and / or mixtures thereof can be mentioned.

The melting point of the biodegradable polymer used in the present invention is as follows:
It is necessary to be 100 ° C. or higher from the viewpoint of heat resistance, more preferably 120 ° C. or higher, and still more preferably 1 ° C. or higher.
40 ° C. or higher. If the temperature is lower than 100 ° C., the heat resistance is poor, which is not practical in the process of producing fibers and nonwoven fabrics, and the use of the obtained nonwoven fabric is extremely limited, which is not preferable. The upper limit of the melting point of the polymer is not particularly limited, but may be about 180 ° C.

In the present invention, it is preferable to use a lactic acid-based polymer derived from lactic acid, which has a relatively high melting point, among the above-mentioned aliphatic polyesters.

Examples of the lactic acid-based polymer include poly-L-lactic acid, poly-D-lactic acid, poly-D, L-lactic acid and a mixture thereof. Among these polylactic acids, L-lactic acid or D-lactic acid having a unit of 90 mol% or more and having optical activity is relatively high in melting point and preferably used from the viewpoint of heat resistance. Can be. Further, a copolymer in which comonomers such as hydroxycarboxylic acids and lactones are copolymerized 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-entrapped acid, 4-hydroxy-entrified acid, 4-hydroxyvaleric acid, hydroxycaproic acid, glycolide, β-propiolactone, β-butyrolactone, ε-caprolactone and the like.

[0014] These lactic acid-based polymers can be produced by polymerizing lactic acid by a conventionally known method. Examples of the polymerization method include, for example, a method in which lactic acid is directly dehydrated and condensed, a method in which lactide which is a cyclic dimer of lactic acid is obtained by ring-opening polymerization, and the like. 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 used in the present invention is a melt flow rate (hereinafter, referred to as MFR) 10.
の も の 100 g / 10 min can be generally used. MF
When R is less than 10 g / 10 minutes, high-speed spinning properties are reduced,
On the other hand, if it exceeds 100 g / 10 minutes, mechanical properties and the like tend not to be sufficiently exhibited. MFR is more preferably 1
5 to 80 g / 10 min, more preferably 20 to 70 g /
10 minutes, most preferably 25-60 g / 10 minutes.
Here, the MFR refers to a value measured at a temperature of 210 ° C. according to the ASTM-D-1238 (E) method.

The biodegradable polymer used in the present invention contains a nutrient salt. In the present invention, the nutrient salt is a salt necessary for normal growth of a plant, and refers to an inorganic substance that becomes a nutrient for phytoplankton and algae.

The nutrients include salts of phosphoric acid, nitric acid, sulfuric acid, silicic acid and the like. These nutrients generate basic ions or acidic ions in the polymer composition under the influence of moisture. The biodegradable polymer is
Hydrolysis proceeds under the influence of these ions, and the molecular weight is further reduced. By increasing the amount of the nutrient salt to be contained in the biodegradable polymer, the biodegradability rate can be increased.In the present invention, the biodegradability rate is controlled by changing the content. It is possible.

As specific nutrients, phosphoric acid salts include calcium phosphate, potassium phosphate, trisodium phosphate, ammonium phosphate, magnesium phosphate and the like. Examples of the nitric acid-based salt include calcium nitrate, ammonium nitrate, sodium nitrate, and potassium nitrate. Examples of the sulfate-based salt include ammonium sulfate, magnesium sulfate, manganese sulfate, and potassium sulfate.
The salt of silicic, although most of the rocks that are on earth are silicate, orthosilicate ion SiO ₄ ⁴ among them ^- and M
Olivine (Mg, Fe) ₂ SiO ₂ with g ²⁺ and Fe ²⁺
And SiO ₃ ^3- and with pyroxene (Registration stone) CaMg (Si
_{O 3) 2, Si 4 O} 11 amphibole (winning stone with ^6-) Ca _{2
Mg 5 (Si 4 O 11)} 2 (OH) 2 and Si ₂ O ₅ Mica KAl ₂ with ^2- _{(AlSi 3 O 10) (OH} ) 2 and the like. Other salts include potassium chloride, calcium carbonate, magnesium oxide, magnesium borate and the like, and these can also be applied as nutrients used in the present invention.

The nutrient salt contained in the biodegradable polymer used in the present invention may be at least one kind selected from the above nutrient salts, and may contain a plurality of kinds. It is preferable to include a plurality of compound fertilizer components by selecting nutrients accompanying the three major nutrients of soil, nitrogen, phosphoric acid, and potassium in a well-balanced manner. In addition, according to the purpose, it may be selected from the above-mentioned nutrient salts corresponding to the calcareous fertilizer, the siliceous fertilizer, the mafic fertilizer, the manganese fertilizer, and the boron fertilizer according to the purpose.

The content of the nutrient salt contained in the biodegradable polymer is preferably 0.5 to 25% by mass, more preferably 1 to 18% by mass, and further preferably 2 to 15% by mass.
% By mass. When the content of the nutrient salt is less than 0.5% by mass, the flexibility is not improved and does not contribute to the decomposition rate. On the other hand, when the content of the nutrient exceeds 20% by mass,
The mechanical strength decreases and the cost increases.

The form of these nutrient salts is preferably a powder. The maximum particle size of the powder is 5 μm or less, more preferably 3 μm or less, and most preferably 1 μm or less. If the maximum particle size of the powder is too large, problems such as clogging of the filtration screen in the spinneret at the time of melt spinning, pressure rise occurs, operability is reduced, and defects occur in the obtained nonwoven fabric product are caused. Cheap. Therefore, when the particle size of the powder is large, it is preferable to perform a pulverizing process in advance. In addition, since the form of the nutrient salt greatly contributes to the operability and the quality stability of the fiber forming process and the nonwoven fabric constituting the nonwoven fabric, it is preferable to use a fine powder having a particle size as small as possible. .

When the biodegradable polymer contains a nutrient salt, it is desirable that the nutrient salt be contained after drying at least at 100 ° C. or higher. Some of the nutrients contain water of crystallization, and can be dehydrated by drying at 100 ° C. or higher, and can prevent the structure and form of the nutrients from changing.

Although the mechanism of the nutrient salt in the fibers constituting the long-fiber nonwoven fabric is not clear, it is considered that the nutrient salt has a cushioning role with the polymer. Is improved.

The single-fiber fineness of the long fibers constituting the biodegradable long-fiber nonwoven fabric of the present invention may be about 0.5 to 15 dtex (hereinafter referred to as dtex). The smaller the single yarn fineness, the better the flexibility of the nonwoven fabric,
If it is less than 0.5 dtex, operation problems such as control of solidification point, increase in accuracy of a die hole, decrease in productivity due to reduction of discharge amount, and occurrence of thread breakage when forming fibers are likely to occur. Undesirably occurs. On the other hand, 15dtex
When it exceeds, the obtained nonwoven fabric has a coarse and hard feeling, and the use tends to be limited. Further, in the process of producing fibers, spinning and drawing become difficult from the viewpoint of cooling and solidification, and special production equipment is required separately, resulting in high cost.

The cross-sectional shape of the long fiber is not particularly limited, and various cross-sectional shapes such as a circular cross section, an irregular cross section, and a hollow cross section can be used. Further, a nonwoven fabric in which long fibers having different cross-sectional shapes are mixed may be used. As the form of long fiber, even in a single layer form composed of a single polymer, a core-sheath type composed of a plurality of polymers, a parallel type, a sea-island type, a radiation split type, a multi-leaf type, a multi-layer type, etc. It may be a composite form. In the composite form, the polymer exposed on the fiber surface may contain the nutrient, or the polymer not exposed on the fiber surface may contain the nutrient.

The nonwoven fabric of the present invention is constituted by long fibers made of the polymer containing a nutrient salt, and the polymer constituting the fibers is molecularly oriented. By the molecular orientation of the polymer, the fiber can be given strength and dimensional stability, and a nonwoven fabric having excellent practical strength and dimensional stability can be obtained.

The strength of the fiber constituting the present invention should be at least 1 cN / dtex or more, but the higher the strength, the more the practical range is widened, and it is more preferable because it can be widely used. If the fiber strength is less than 1 cN / dtex, the strength as a nonwoven fabric is low, which is not practical, and the usage tends to be limited. The fiber strength is more preferably 1.5 cN / dtex or more, and further preferably 2.0 cN / dtex.
/ Dtex or more, most preferably 2.5 cN / dte
x or more.

In the present invention, if necessary, for example, a heat stabilizer, a crystal nucleating agent, a matting agent,
Pigments, light stabilizers, weathering agents, lubricants, antioxidants, antibacterial agents, fragrances, plasticizers, dyes, surfactants, flame retardants, surface modifiers,
Various inorganic and organic electrolytes and other similar additives can be added within a range that does not impair the purpose of the present invention.

The long-fiber nonwoven fabric according to the present invention is composed of the fibers described above, and retains its shape. As the holding means of the form, a method of thermally bonding the contact points of the fibers by heat, a method of forming a partial thermocompression bonding portion and thermocompression bonding the fibers (partial thermocompression method), and a method of mechanically bonding the fibers to each other And a method of adhering fibers to each other with an adhesive. Among them, the partial thermocompression bonding method is preferable because a nonwoven fabric with high flexibility can be obtained while maintaining the strength of the nonwoven fabric at a relatively high level, and the productivity is high and the nonwoven fabric can be provided at the lowest cost.

The shape of the partial thermocompression bonding portion is triangular, quadrangular,
Polygonal shapes such as pentagonal, hexagonal, and octagonal shapes, diamond shapes, round shapes, elliptical shapes, and texture patterns can be used. In addition, the crimping area ratio of the thermocompression bonding portion is 3 to 50%, and the crimping point density is 4 to 60 pieces / cm.
It is preferably ² . When the compression area ratio exceeds 50% or the compression point density exceeds 60 pieces / cm ² , the flexibility tends to decrease, while the compression area rate is less than 3% or the compression point density is less than 4 pieces / cm ^2. In such a case, the strength of the nonwoven fabric tends to decrease and fluffing tends to occur.

In the long-fiber nonwoven fabric of the present invention,
The NSM strength in any of the lateral directions is 7N /
It is preferably at least 5 cm wide. Here NSM powerful
Is measured in accordance with JIS L 1096 strip method.
The specified value is 100 g / m ^TwoIt is converted to
The higher the NSM strength, the better, but 7N / 5cm width
If it is above, it can be handled well practically.

The flexibility of the long-fiber nonwoven fabric of the present invention is as follows:
In the present invention, the compression hardness is preferably 3.0 cN / (g / m ² ) or less. The compression bending resistance indicates that the smaller the value, the better the flexibility.

Next, a preferred method for producing the long-fiber nonwoven fabric of the present invention will be described.

First, a biodegradable polymer and a nutrient salt are mixed to obtain a biodegradable polymer containing a nutrient salt,
The polymer is melt spun. The mixing method and the mixing apparatus are not particularly limited, and the mixing can be performed by conventional means.

Among them, those which can be continuously measured and mixed are industrially preferable, and those having good quality can be obtained. For example, a nutrient salt weighed on a biodegradable polymer chip may be dry-blended, melted by a single-screw extruder, a twin-screw kneading extruder, or the like, and immediately spun.

The nutrient salt is weighed and dry-blended on the biodegradable polymer chips, melt-kneaded with a twin-screw kneading extruder, spun into strands, cooled, cut, and cut into masters. The chips are manufactured as a batch. The masterbatch and the biodegradable polymer may be separately melted, mixed at a predetermined ratio by a static mixer and / or a dynamic mixer, and melt-spun.

Further, the masterbatch and the biodegradable polymer may be supplied to a metering mixing device using a jet collar or the like, and may be melt-mixed by an extruder or the like, and then melt-spun. In the melt mixing method, it is necessary to substantially prevent the deterioration of the polymer, the qualities, and the copolymerization due to the transesterification reaction, and it is preferable to mix and spin at a temperature as low as possible and within a short time.

For spinning, the above-mentioned dry blending method or the mixing method with a master batch using a jet color may be applied. However, after individual melting and measurement by a composite spinning device, mixing by a static mixer is performed in a spinneret. The spinning may be performed by discharging the polymer from the die.

[0039] The spun fiber yarn is drawn with or without hot drawing, and is then spread and collected on an endless wire mesh to form a fiber web. Next, the obtained fiber web is introduced into an embossing device including a pair of embossing rolls equipped with an engraving roll, or an embossing device including an embossing roll and a flat roll.
The non-woven fabric can be obtained by partially thermocompression bonding between the fibers.

If necessary, the fibrous web or the partially thermocompressed nonwoven fabric is introduced into a heating flat calender, a hot air circulation type dryer, a hot air once-through type dryer, a suction drum type dryer, or the like. Heat bonding may be used. Also,
The fiber web may be subjected to a needle punching treatment, and the fibers may be entangled to maintain the form, and then, if necessary, thermally bonded by the heat treatment means described above.

[0041]

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 at which the extreme value was given was defined as a glass transition temperature (hereinafter, referred to as Tg) and a melting point (hereinafter, referred to as Tm).

(2) Spreadability of spun yarn: The nonwoven fabric was visually evaluated according to the following three grades. 〇: Most of the constituent fibers were opened, and cohesive yarns and bundled yarns were not observed. Δ: Cohesive yarn and bunched yarn are recognized in only a part of the constituent fibers. ×: Most of the constituent fibers adhered, and the spreadability was poor.

(3) Weight (g / m ² ): Ten samples of 10 cm long × 10 cm wide were prepared from the sample in the standard condition.
After adjusting the water content to an equilibrium, the weight of each sample piece was weighed, and the average value of the obtained values was converted into a unit area to obtain the basis weight (g / m ² ).

(4) NSM strength of nonwoven fabric (N / 5cm)
And elongation (%): A sample having a sample width of 5 cm and a sample length of 20 cm using a constant-speed extension-type tensile tester (Tensilon UTM-4-100 manufactured by Toyo Baldwin Co., Ltd.) according to the strip method described in JIS L-1096. Ten pieces were prepared and measured at a gripping interval of 10 cm and a pulling speed of 10 cm / min. The average value of the individual maximum tensile strengths was calculated as 100 g /
The NSM strength was calculated in terms of m ² . Further, the average value of the elongation at the time when the maximum strength was exhibited was defined as the elongation (%) of the nonwoven fabric.

(5) Compression stiffness (cN / (g /
m ² )): 5 sample pieces each having a sample length of 10 cm and a sample width of 5 cm
Each piece was prepared, and each sample piece was bent in the lateral direction to have a cylindrical shape, and the ends thereof were joined to form a measurement sample. Next, each measurement sample was moved in the axial direction with a constant-speed extension-type tensile tester (
Toyo Baldwin Tensilon UTM-4-10
0), the measurement sample was compressed at a compression speed of 5 cm / min, the average value of the obtained maximum load values (cN) was obtained, and the average value was divided by the basis weight (g / m ² ) of the sample. The compression stiffness (cN / (g / m ² )) was used.

(6) Evaluation of biodegradability: Five non-woven fabric sample pieces (10 cm long × 5 cm wide) were placed in the soil outdoors and from the ground surface.
It was buried at a depth of 0 cm. After 6 months and / or
Or, after 12 months, they were dug out, visually observed and measured for strength, and observed to determine the biodegradability shown below. ×: No change at all △: Retained form, but retention of tensile strength was 60%
It has dropped below. 〇: Shape partially collapsed. A: Almost collapsed.

Preparation of Master Batch First, a master batch was prepared. As a nutrient, Table 1
The dried nutrients shown in the following were prepared. The following three kinds of biodegradable polymers were prepared. That is, a poly L-lactic acid resin having a glass transition temperature of 62 ° C., a melting point of 168 ° C., and an MFR of 20 g / 10 min (hereinafter referred to as B1 or B1 polymer), a glass transition temperature of 42 ° C., a melting point of 165 ° C., and an MF.
Hydroxycarboxylic acid having R of 20 g / 10 min.
5 mol copolymerized poly-L-lactic acid resin (hereinafter referred to as B2 or B2 polymer), butane succinic acid with glass transition temperature of -32 ° C, melting point of 115 ° C, MFR of 30 g / 10 min, equimolar A polybutylene succinate resin (hereinafter referred to as C1 or C1 polymer) polymerized in an amount was prepared.

To the biodegradable polymer shown in Table 1, nutrients in the amounts shown in Table 1 were added and mixed to prepare a master batch. That is, a measured amount of a nutrient salt was dry-blended onto a polymer chip, melt-kneaded at a temperature of 200 ° C. using a biaxial kneading extruder kneader, and spun from two holes of a die head into a strand shape. After cooling the obtained strand, the strand was cut and used as a master batch. Eight types of masterbatches A1 to A8 were obtained.

[0049]

[Table 1]

Examples 1 to 5 Polylactic acid resin (optical purity 98.8% (copolymerization ratio of L-form / D-form is 98.8 / 1.2)), glass transition temperature 73 ° C., melting point 169 ° C., MFR 35 g / 10 minutes) and the master batches (A1, A2, A4 to A6) were individually weighed and mixed so as to have a nutrient content of 5% by mass in the combinations shown in Table 2, and then extruded. Melted in the machine,
Melt spinning was performed at a spinning temperature of 210 ° C. and a single hole discharge rate of 1.5 g / min from a spinneret having a round hole.

Next, the spun yarn is cooled by a cooling device,
The web was drawn at a drawing speed of 5000 m / min, pulled by a suction jet, and passed through a spreader to form a web composed of 3dtex fibers. Subsequently, this fiber web is embossed with a diamond-shaped engraving pattern (set temperature 130 ° C.).
And a flat roll (set temperature: 130 ° C.) to obtain a long-fiber nonwoven fabric having a basis weight of 50 g / m ² (compression area ratio of 11%, compression point density of 22 pieces / cm ² ). Table 2 shows the performance evaluation results of the obtained long-fiber nonwoven fabric.

[0052]

[Table 2]

As is clear from Table 2, the long-fiber nonwoven fabrics of Examples 1 to 5 had practical mechanical performance, excellent flexibility, and quick and excellent biodegradability. Examples 6-9, Comparative Example 1 Polylactic acid resin (optical purity 98.8% (copolymerization ratio of L-form / D-form is 98.8 / 1.2), glass transition temperature 73 ° C, melting point 169 ° C, MFR 48g) / 10) and the master batch (A3) were individually weighed and mixed at the nutrient content shown in Table 3, and then melted with an extruder-type extruder.
At a spinning temperature of 210 ° C. and a single-hole discharge rate of 1.35 g / min, melt spinning was performed from a spinneret having a round hole.

Next, the spun yarn is cooled by a cooling device,
It was pulled at a pulling speed of 4500 m / min, pulled by a suction jet and passed through a spreader to form a web composed of 3dtex fibers. Subsequently, the fibrous web was introduced into the same embossing apparatus as in Example 1 and subjected to a thermocompression treatment to obtain a long-fiber nonwoven fabric having a basis weight of 50 g / m ² . Table 3 shows the performance evaluation results of the obtained long-fiber nonwoven fabric.

[0055]

[Table 3]

As is evident from Table 3, the long-fiber nonwoven fabrics of Examples 6 to 9 have practical mechanical performance. It can be seen that the decomposition rate can be controlled by the nutrient content.

On the other hand, in Comparative Example 1, although having practical mechanical performance, the flexibility was poor and the biodegradation period was extremely long.

Example 10 Poly-L-lactic acid copolymer resin obtained by copolymerizing 1.5 mol of hydroxycarboxylic acid (glass transition temperature: 42 ° C., melting point: 16
5 ° C., MFR 40 g / 10 min; hereinafter referred to as B3 or B3 polymer. ) And a master batch (A7). Using a composite type spinning apparatus consisting of two extruders, after individually melting and weighing, a hole diameter of 0.3 from the spinneret having four stages of a through-slurry static mixer in the spinneret apparatus.
The fiber was spun from a hole of mm. As spinning conditions, the spinning temperature was 210 ° C., the single-hole discharge amount was 1.35 g / min (the B3 single-hole discharge amount was 1.01 g / min, and the A1 single-hole discharge amount was 0.34 g / min.
Min), the traction speed was 4000 m / min, and the sample was drawn with a suction jet. Pass the spun yarn through an opener, 3 dt
ex of fibers.

[0059] subjected to a thermocompression bonding process by introducing the same embossing apparatus as in Example 1 to obtain a long-fiber nonwoven fabric of basis weight 50 g / m ^2. Table 4 shows the performance evaluation results of the obtained long-fiber nonwoven fabric.

Example 11 A master blend (A7) and a B3 polymer used in Example 10 were blended using a jet color mixer at a mixing ratio (weight ratio) of A7: B3 = 1: 9. The product was supplied to one extruder of a composite spinning device and melt-weighed at a temperature of 210 ° C.

On the other hand, the master batch (A8) and the polybutylene succinate resin (C1) were mixed at a mixing ratio (weight ratio) of A8: C1 = 1: 9 using a jet color mixer.
The blended metered blend was supplied to the other extruder of the composite spinning apparatus, and was melt-weighed at a temperature of 200 ° C.

The separately weighed polymer was subjected to composite spinning in a core-in-sheath type using a composite spinneret at a temperature of 210 ° C. using the former component as a core component and the latter component as a sheath component, and then the jet was pulled at a speed of 3500 m / min. Pull and pass through the opener, 2 dte
A web consisting of x fibers was formed. Note that the core-sheath composite ratio
(Weight ratio) was 1: 1 and the single hole discharge rate was 0.7 g / min.

Subsequently, the fibrous web was introduced into an embossing device comprising an embossing roll (a set temperature of 90 ° C.) having a circular engraving pattern and a flat roll (a set temperature of 90 ° C.), and a fibrous nonwoven fabric having a basis weight of 50 g / m ² was obtained. (Crimping area ratio 7
% And a compression point density of 44 pieces / cm ² ). Table 4 shows the performance evaluation results of the obtained long-fiber nonwoven fabric.

Example 12 The mixing ratio (weight ratio) of the master batch (A6) and the B3 polymer was determined using a jet color mixer, A6: B3 =
At 3: 7, the blended metered blend was fed to one extruder of a composite spinning device and melt-weighed at a temperature of 210 ° C.

On the other hand, a blend obtained by blending the master batch (A7) and the C1 polymer at a mixing ratio (weight ratio) of A7: C1 = 3: 7 using a jet color mixer was used to form the other extrude of the composite spinning apparatus. It was supplied to a ruder and melted and weighed at a temperature of 200 ° C. The former component as the core component,
Using the latter component as a sheath component, this individually melt-weighed polymer is compound-spun into a core-sheath type with a compound spinneret at a temperature of 210 ° C., and the drawing speed of the jet is drawn at 3500 m / min. This was passed to form a web composed of 2dtex fibers. The single hole discharge rate was 0.7 g / min.

Subsequently, this fibrous web was subjected to a partial thermocompression treatment in the same manner as in Example 11 except that the set temperature of the roll was set to 95 ° C., to obtain a fibrous nonwoven fabric having a basis weight of 50 g / m ² . Table 4 shows the performance evaluation results of the long fiber nonwoven fabric.

Example 13 A masterbatch (A8) and a polybutylene succinate / adipate copolymer resin obtained by copolymerizing butanediol with succinic acid and adipic acid at a ratio of 100/80/20 (glass transition temperature -45 ° C.) , Melting point 105 ° C, MFR3
0 g / 10 min; hereinafter referred to as D1 or D1 polymer. )
(A8: D1 = 7: 3)
(Mixing weight ratio)) and a blend (A8: C) obtained by blending the master batch (A8) and the C1 polymer.
1 = 7: 3 (mixing weight ratio)) were individually melt-weighed at a temperature of 200 ° C.

Using the former component as an island component and the latter component as a sea component, compound spinning is subsequently performed at 200 ° C. using a sea-island type compound spinneret device having eight island components, and a jet pulling speed of 3500 m / min. And passed through an opener to form a web of 2dtex fibers. The single hole discharge rate was 0.7 g / min.

Subsequently, the fibrous web was subjected to a partial thermocompression treatment in the same manner as in Example 11 to obtain a long-fiber nonwoven fabric having a basis weight of 50 g / m ² . Table 4 shows the performance evaluation results of the long fiber nonwoven fabric.

Comparative Example 2 An attempt was made to produce a long-fiber nonwoven fabric under the same conditions as in Example 13 except that no nutrient salt was used. Table 4 shows the results.

[0071]

[Table 4]

As apparent from Table 4, Examples 10 to 1
3 Long-fiber nonwoven fabric has practical mechanical performance,
It was found that a fiber having excellent flexibility was obtained and the biodegradability was fast, and that the rate of biodegradability could be controlled depending on the type of nutrient. In particular, Example 10 was excellent in mechanical properties, Examples 11 and 12 were particularly excellent in flexibility, and Example 13 was extremely excellent in flexibility.

On the other hand, in Comparative Example 2, the fibers adhered to each other and the spinning property was poor, and a long-fiber nonwoven fabric could not be obtained.

[0074]

According to the present invention, by mixing a nutrient agent into a biodegradable polymer, not only mechanical properties such as flexibility can be improved, but also when used, it can be disposed of. In this case, it is possible to control the rate of decomposition in nature. In addition, when it is reduced to soil, it becomes an active nutrient source and can contribute to the growth of plants and the like as a safe fertilizer. is there. Furthermore, the nutrient salt contained in the biodegradable polymer, as the biodegradable polymer is degraded, since the effect as a fertilizer is gradually exhibited,
Useful for plants as a slow release fertilizer.

The long-fiber nonwoven fabric of the present invention comprises a sheet for raising seedlings,
Cold gauze, house wrap, string, insect-proof sheet, grass-proof sheet,
Agricultural and forestry materials such as sandbags, vegetation sheets, civil engineering and industrial materials,
It can be suitably used in a wide range of fields such as household and household goods such as various filters and garbage bags, various containers and packaging materials such as draining nets, and various composite materials.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) A01G 13/02 A01G 13/02 D 13/10 13/10 A A01M 29/00 A01M 29/00 R F-term (reference) 2B022 BA01 BA23 BB02 2B024 DA03 DB03 DB10 GA01 2B027 NC05 NC12 NC24 NC37 NC39 ND03 ND09 ND15 2B121 AA11 BB27 EA24 EA25 FA16 4L047 AA21 AA29 AB03 CA19 CB01 CB10 CC15

Claims (4)

[Claims] A melting point of 1 containing at least a nutrient salt.
A biodegradable long-fiber nonwoven fabric comprising a long fiber made of a biodegradable polymer at a temperature of 00 ° C or higher. 2. The biodegradable long-fiber nonwoven fabric according to claim 1, wherein the biodegradable polymer is a lactic acid-based polymer. 3. The nutrient salt is at least one of a phosphoric acid type, a nitric acid type, a sulfuric acid type and a silicic acid type salt, and the biodegradable polymer contains 0.5 to 25% by mass of the nutrient salt. The biodegradable long-fiber nonwoven fabric according to claim 1 or 2, wherein 4. The long-fiber nonwoven fabric has a longitudinal and / or transverse NSM strength of 7 N / 5 cm or more in width and a compression bristles of 3.
0cN / (g / m ²⁾ biodegradable filament nonwoven fabric according to any one of claims 1 to 3, wherein the less.