JPH1046463A - Biodegradable long-fiber nonwoven fabric and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a continuous filament nonwoven fabric, excellent in flexibility and strength, having the biodegradability with microorganisms and capable of controlling the degradation rate thereof. SOLUTION: This biodegradable continuous filament nonwoven fabric is prepared by thermally melting an aliphatic polyester polymer, extruding and spinning the resultant melt through a spinneret, drawing the formed filaments through an ejector, collecting and depositing a filament group of continuous filaments on a support, and carrying out the partial thermo compression bonding of the resultant web. In this case, a thermoplastic resin constituting the continuous filaments is composed of mixed resins of 50-90wt.% polybutylene succinate polymer synthesized from 1,4-butanediol and succinic acid with 10-50wt.% polybutylene succinate adipate copolymer synthesized from the 1,4-butanediol, succinic acid and adipic acid. The thermoplastic resin has a melt flow rate within the range of 15-80g/10min according to JIS K 7210 and the difference in values of melt flow rate between the mixed resins is within the range of 0-20. The content of the adipic acid in the polybutylene succinate adipate is 5-35mol%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a long-fiber nonwoven fabric which is excellent in flexibility and strength, has biodegradability, and can control the decomposition rate thereof, and a method for producing the same. It can be used in a wide range of fields such as general industrial materials.

[0002]

2. Description of the Related Art Spunbonded nonwoven fabrics using long fibers as constituent fibers are used for various purposes because they are higher in strength and relatively inexpensive than short fiber nonwoven fabrics containing short fibers as constituent fibers. As a fiber material constituting the spunbonded nonwoven fabric, a thermoplastic resin made of a polymer such as polyethylene, polypropylene, polyester, or polyamide is generally used. However, spunbonded nonwoven fabrics made of these materials have no self-decomposability and are chemically very stable under ordinary natural environments. Accordingly, at present, disposable nonwoven fabrics are treated by incineration or landfill after use. Although incineration is widely performed in Japan, it is not only expensive but also toxic gas such as cyan gas may be generated in the case of nylon-based long-fiber non-woven fabric which is polyamide. Pollution due to waste plastics is being generated, and how to solve the problem of disposal of waste plastics is a major social problem in terms of protection of the natural environment and living environment.

On the other hand, there is a problem with landfills in that the materials are chemically stable and therefore remain in the original state for a long time in soil. As a method for solving such a problem, there is a demand for the appearance of a new spunbonded nonwoven fabric which is naturally degraded within a short period of time by using a material having natural degradability. Biodegradable polymers include polysaccharides such as chitin and cut gut (intestinal tract)
And polypeptides (polyamino acids), such as collagen and regenerated collagen, microbial polyesters such as poly-3-hydroxybutyrate, poly-3-hydroxyvalerate, poly-3-hydroxycaprolate, etc., produced by microorganisms in nature. Synthetic aliphatic polyesters such as glycolide and polylactide are known. However, when producing fibers from these polymers, there is a problem that the melt spinnability essential for spunbonding is very poor and processing cannot be carried out using a commonly used spunbonded nonwoven fabric production apparatus. In addition, since the cost of the material is extremely high, it is not suitable as a general disposable living material such as a disposable diaper, a sanitary material such as a cover stock for sanitary goods, a wiping cloth, a packaging material, and the like.

In order to solve the above problem, Japanese Patent Laid-Open No.
No. 57953 discloses a spunbonded nonwoven fabric made of polyethylene containing 3 to 30% by weight of a polycaprolactone as a biodegradable polymer. However, the spunbonded nonwoven fabric cannot be said to be a biodegradable spunbonded nonwoven fabric in the original sense because polyethylene does not degrade semipermanently. Further, Japanese Patent Application Laid-Open No.
Japanese Patent No. 4648 discloses a spunbond nonwoven fabric comprising poly-ε-caprolactone and / or poly-β-propiolactone. In this case, the material can be made completely biodegradable, but the melting point of poly-ε-caprolactone is around 60 ° C. and the melting point of poly-β-propiolactone is around 100 ° C. There is a problem that it is not suitable for practical materials due to poor properties.

Further, JP-A-7-48768, JP-A-7-34369 and JP-A-8-60513 are characterized in that a glycol and an aliphatic dicarboxylic acid or a derivative thereof are contained as constituent units. A long-fiber nonwoven fabric made of an aliphatic polyester resin is disclosed. Although this nonwoven fabric substantially solves the above problems, it is the actual situation that both the spinnability and the biodegradability have not reached satisfactory levels in practical use. That is, as the aliphatic polyester suitable for melt spinning and usable for long-fiber nonwoven fabric, in the case of a polybutylene succinate polymer synthesized from 1,4-butanediol and succinic acid, the melt spinnability is good. Although a biodegradable long-fiber nonwoven fabric having excellent strength and feeling can be obtained, there is a disadvantage that the biodegradation rate is low.

A polybutylene succinate-adipate copolymer, which is an aliphatic polyester synthesized from 1,4-butanediol and succinic acid and adipic acid,
Conversely, the biodegradation rate is fast, but the crystallization rate is slow and the solidification of the filament on the melt spinning line is slow. Therefore, unless the spinning length (the distance from the exit of the die to the entrance of the ejector) is extremely long, the normal span pound In the non-woven fabric manufacturing equipment,
There is a disadvantage that fusion between the yarns easily occurs, the feeling of the obtained long-fiber nonwoven fabric is inferior, and the flexibility deteriorates. Furthermore, when it is necessary to control the biodegradation rate in accordance with the application, the current situation is that the current biodegradable long-fiber nonwoven fabric is not yet at a satisfactory level.

[0007]

SUMMARY OF THE INVENTION The present inventors have conducted intensive studies in view of the above situation, and as a result, have found that the polybutylene succinate-adipate copolymer has excellent biodegradability and polybutylene succinate polymerization. Focusing on the excellent melt-spinning properties of the products, and maintaining the mixing ratio of these resins in a specific range, the biodegradation rate can be controlled very easily without impairing the spinnability, and the flexibility and formation And found that a long-fiber nonwoven fabric having excellent strength was obtained, and completed the present invention. Accordingly, an object of the present invention is to provide a biodegradable long-fiber nonwoven fabric which is easily decomposed by microorganisms, and whose decomposition rate can be easily controlled, and which is excellent in flexibility, formation and strength, and a method for producing the same. is there.

[0008]

Means for Solving the Problems The first aspect of the present invention is to heat and melt a thermoplastic aliphatic polyester resin, extrude and spin from a die of an extrusion spinning machine, and spin a spun continuous filament filament group from an ejector. Stretch with high speed air,
After charging and opening, collecting and accumulating on a support to form a web, and forming a web, the biodegradable long-fiber nonwoven fabric obtained by partially thermocompressing the web contains resin constituting the long fiber. 50 to 90% by weight of a polybutylene succinate polymer synthesized from 1,4-butanediol and succinic acid;
A biodegradable long-fiber nonwoven fabric comprising a mixed resin of 4-butanediol and 50 to 10% by weight of a polybutylene succinate-adipate copolymer synthesized from succinic acid and adipic acid. . In the second aspect of the present invention, the thermoplastic aliphatic polyester resin is heated and melted, extruded and spun from a die of an extrusion spinning machine, and a spun continuous filament filament group is stretched by high-speed air from an ejector and charged. In the method for producing a biodegradable long-fiber nonwoven fabric, which comprises collecting and accumulating a web on a support to form a web, and further thermocompressing the web partially, the thermoplastic resin is used as the thermoplastic resin. 50-90% by weight of a polybutylene succinate polymer synthesized from 1,4-butanediol and succinic acid; and polybutylene succinate-adipate synthesized from 1,4-butanediol, succinic acid and adipic acid A method for producing a biodegradable long-fiber nonwoven fabric, comprising mixing and using 50 to 10% by weight of a polymer. A third aspect of the present invention is that the thermoplastic resin has a melt flow rate according to JIS K7210 in a range of 15 to 80 g / 10 minutes, and a difference in melt flow rate between the resins before mixing is 0 to 20.
The present invention provides a method for producing a biodegradable long-fiber nonwoven fabric according to the second aspect of the present invention, wherein A fourth aspect of the present invention is the biodegradable long-fiber nonwoven fabric according to the second aspect of the present invention, wherein the content of adipic acid in the polybutylene succinate-adipate copolymer is 5 to 35 mol%. It is a manufacturing method.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The aliphatic polyester polymer used in the present invention is a polybutylene succinate polymer synthesized from 1,4-butanediol and succinic acid, and 1,4-butanediol.
A polybutylene succinate-adipate copolymer synthesized from butanediol, succinic acid, and adipic acid. These resins have a melt flow rate measured by a method described in JIS K 7210 (190 ° C .; 2160 g load). It has a range of 15-80 g / 10 minutes. A polybutylene succinate polymer and a polybutylene succinate-adipate copolymer having a melt flow rate of less than 15 g / 10 minutes are not preferred because their melt viscosities are too high, thread breakage tends to occur frequently, and spinning may not be possible.
Conversely, if the melt flow rate exceeds 80 g / 10 minutes, thread breakage is likely to occur, which not only reduces the texture of the obtained long-fiber nonwoven fabric but also lowers the strength, which is not suitable.

Furthermore, it is desirable that the difference between the respective melt flow rates of the polybutylene succinate polymer and the polybutylene succinate-adipate copolymer be within the range of 0 to 20. If the difference in the melt flow rate exceeds 20, it is not preferable because the spinning property deteriorates due to distortion caused by too different melt elongation characteristics between the mixed resins. In the present invention, a polybutylene succinate polymer and a polybutylene succinate-adipate copolymer are mixed and used at different mixing ratios, and spun in a known extruder for producing a spunbonded nonwoven fabric to obtain a nonwoven fabric. Can be The mixed resin is heated and melted,
A large number of continuous filament filaments formed by being extruded and spun from a die of an extruder and then stretched with high-pressure air by an ejector are frictionally charged by hitting an impact plate, or charged by Konaro discharge treatment or the like, The fiber is opened by the repulsive force of the electric charge.

Thereafter, the opened filaments are deposited and collected on a support to form a web, and the web is self-fused at regular intervals for the purpose of maintaining the form of the sheet and imparting strength. A landing area is provided. This self-fusion area is introduced between the uneven roll and the smooth roll heated by heating the long fiber web, and by applying heat and pressure treatment, the sheet portion corresponding to the convex portion of the uneven roll is fused. It is formed. In the present invention, various additives such as a lubricant, a wax, a coloring agent, a crystallization accelerator and the like are added to the resin as required, for example, in addition to an antioxidant, a heat stabilizer, an ultraviolet absorber, and the like. It can be added within a range that does not impair the effects of the invention.

The aliphatic polyester resin constituting the biodegradable long-fiber nonwoven fabric according to the present invention includes 50 to 90% by weight of a polybutylene succinate polymer synthesized from 1,4-butanediol and succinic acid; A mixture of 4-butanediol and 10 to 50% by weight of a polybutylene succinate-adipate copolymer synthesized from succinic acid and adipic acid. Polybutylene succinate-adipate copolymer is a random copolymer, and has a lower crystallization rate, lower crystallinity, and a higher biodegradation rate than polybutylene succinate homopolymer, but slow solidification of the filament on the spinning line Therefore, when the proportion of the polybrylene succinate-adipate copolymer in the mixture exceeds 50% by weight, fusion may occur between filament filaments, and the spinnability and the spreadability may be significantly deteriorated. Absent. On the other hand, if the proportion of the polybutylene succinate-adipate copolymer is less than 10% by weight, no effect is exhibited, which is not suitable.

Further, the polybutylene succinate.
The content of adipic acid is 5 to 3 in the adipate copolymer.
It is desirable to be within the range of 5 mol%. When the content of adipic acid exceeds 35 mol%, the melting point of the copolymer becomes low, and the difference from the melting point of the polybutylene succinate polymer becomes too large. It is not preferable because it becomes difficult to set melt spinning conditions for maintaining good conditions. On the other hand, when the content is less than 5 mol%, the difference between the crystallization rate, crystallinity and biodegradation rate of the copolymer is smaller than that of the polybutylene succinate polymer. Is not preferred because it becomes difficult. As described above, by adjusting the mixing ratio of the polybutylene succinate polymer and the polybutylene succinate-adipate copolymer, the content of adipic acid in the polyethylene succinate-adipate copolymer is controlled by the above-described method. By changing within the range, the biodegradation rate can be changed according to the purpose of use, and the biodegradability of the nonwoven fabric can be controlled.

The fineness of the fibers used in the long-fiber nonwoven fabric of the present invention is in the range of 1 to 10 denier. If the fineness of the long fiber exceeds 10 denier, the fiber diameter becomes too large, and the resulting nonwoven fabric becomes hard and the hand feel deteriorates. next,
The cross-sectional shape of the long fiber may be irregular or flat in addition to the circular cross-section. The basis weight of the long-fiber nonwoven fabric of the present invention is in the range of 5 to 200 g / m ² . The reason for this is that if the basis weight of the non-woven fabric exceeds 200 g / m ² , the non-woven fabric becomes too hard, the texture becomes hard, and the basis weight becomes 5 g / m 2.
^If it is less than ² , the strength of the nonwoven fabric is too low, and it is difficult to stably produce the nonwoven fabric. In the present invention, a biodegradable long-fiber nonwoven fabric can be manufactured using a known extrusion melt spinning apparatus.

[0015] As described above, the mixed resin is heated and melted in an extruder, extruded from a die, and the spun filament filaments are stretched by high-pressure air from an ejector, and then triboelectrically charged against an impingement plate. And the fiber is opened by the repulsive force of the electric charge. In this case, corona discharge treatment can be performed as a charging method. A large number of long fibers that are uniformly opened are deposited and collected on a support and formed into a web. The multiple long fiber webs collected on the support are then partially heat bonded to provide self-fused areas of the fibers at regular intervals. This self-fusing zone is used to deposit a large number of long fiber webs
The sheet is introduced between the heated concavo-convex roll and the smooth roll, and subjected to heat and pressure treatment, whereby the sheet portion corresponding to the convex portion of the concavo-convex roll is formed by fusing.

In this case, the temperature of the roll is lower than the melting point of the mixed resin, which is determined by the mixing ratio of the mixed resin, in the range of 5 to 35 ° C. If the difference between the roll temperature and the melting point of the mixed resin is less than 5 ° C., the fibers adhere to the roll during thermocompression treatment with the roll, which is not preferable because it causes manufacturing trouble. Conversely, the difference between the roll temperature and the melting point of the mixed resin is 3
If the temperature exceeds 5 ° C., the formation of the self-fused portion becomes insufficient,
Not only is the strength of the sheet significantly reduced, but the sheet is unduly fuzzy. The pressure when the thermocompression treatment is performed with the uneven roll and the smooth roll is 10 to 80 kg / cm, preferably 20 to 60 kg / cm. Pressure is 10kg
If it is less than 80 kg / cm, the self-fused area may be insufficiently formed, and if it is more than 80 kg / cm, the self-fused area may be in the form of a film and the texture of the nonwoven fabric may be impaired.

As a method for forming the self-fused area, a continuous continuous fiber web is introduced between an uneven roll and an ultrasonic horn, and is subjected to ultrasonic treatment so that a point fusion corresponding to the convex portion is obtained. It is also possible to form the attachment part. In the present invention, the area of each self-fusion zone is 0.03.
４4 mm ² . The area of the self-fusion area is 0.0
If it is less than 3 mm ² , the sheet strength will be insufficient, and if it exceeds 4 mm ² , the sheet will be too hard and unsuitable. The total area of the self-bonding area is 2 to 30 area% of the total surface area of the long-fiber nonwoven fabric. If the total area of the self-fusing area is less than 2% by area, the strength of the nonwoven fabric sheet is insufficient,
Conversely, if the self-bonding area exceeds 30 area%, the nonwoven fabric sheet becomes hard and unsuitable. The long-fiber nonwoven fabric obtained as described above has excellent flexibility and strength, and a desired decomposition rate is imparted by microorganisms in compost, wet soil, water containing activated sludge, seawater, and the like. It has the ability to decompose completely and is processed variously as needed, and is used for sanitary materials, medical substrates, clothing substrates, household substrates, industrial substrates and the like.

[0018]

EXAMPLES The present invention will be described more specifically with reference to examples below, but the present invention is of course not limited to these. In the following examples,% is% by weight unless otherwise specified.

Example 1 Polybutylene succinate having a melt flow rate of 40
70% of polymer (trade name: Bionore, manufactured by Showa High Polymer Co., Ltd.)
And the melt flow rate is 30 and the content of adipic acid is
20 mol% of polybutylene succinate and adipate
30% of polymer (trade name: Bionore, manufactured by Showa High Polymer Co., Ltd.)
Was mixed to prepare a mixed resin. Next, the known extrusion
Heat and melt the mixed resin using a spinning device,
After extruding and spinning from the fine holes of the spinneret,
Stretching the group with high-speed air by the ejector and hitting the plate
To open the wire, and then move the wire-shaped support
It was collected and accumulated on a holding body to form a long fiber web. Long
The fineness of the fiber was 2.4 denier. Next, this long fiber
Of uneven roll and smooth roll heated to 85 ° C
Between the rolls to fuse the part corresponding to the convex part of the uneven roll
By doing, the basis weight 40g / m ^TwoLong fiber nonwoven fabric
Was. The linear pressure of the roll is 40 kg / cm
The area of each self-fusion zone is 0.12mm^TwoAnd self
The total area of the fused area is 4% by area per total area of the nonwoven fabric.
there were. Test the obtained long-fiber nonwoven fabric by the following test method
And evaluated its quality.

Test method (1) Microbial decomposition rate: 40 long-fiber nonwoven fabrics having a size of 10 cm × 25 cm were used outdoors in Koto-ku, Tokyo (1-10-6 Shinonome, Koto-ku, Tokyo, Shin-Oji Paper Co., Ltd. Buried at a depth of 25 cm in the soil (in the Shinonome Research Center), take out three sheets every month, observe the morphological change of the nonwoven fabric,
The time (months) when the morphology varied and the average value of weight loss became 50% was measured and observed for 12 months. (2) Spinnability: The spinnability of the resin was evaluated based on the amount of yarn breakage during melt spinning. The evaluation was performed in the following five stages. 5: No yarn breakage, and spinning properties are extremely good. 4: There is almost no yarn breakage, and the spinnability is good. 3 ... The yarn breakage is a little, but it does not matter and the spinnability is normal. 2 ... Yarn breakage is considerable and spinnability is poor. 1: Very many yarn breaks and spinning properties are extremely poor. (3) Possibility of producing long-fiber nonwoven fabric: The feasibility of producing long-fiber nonwoven fabric was evaluated in the following three stages. ×: Production of long fiber nonwoven fabric is impossible. Δ: Production of long-fiber nonwoven fabric is difficult, and a good sheet cannot be obtained.・ ・ ・: Production of long-fiber nonwoven fabric is easy, and a good sheet is obtained.

(4) Formation of nonwoven fabric: The formation of the obtained long-fiber nonwoven fabric was evaluated organoleptically. The evaluation was performed in the following five stages. 5 ... The formation is extremely good. 4: The formation is good. 3: The formation is normal. 2 ... The formation is bad. 1 ... The formation is extremely bad. (5) Flexibility: The flexibility of the obtained long-fiber nonwoven fabric was evaluated organoleptically. The evaluation was performed in the following five stages. 5 ... Very good flexibility. 4: Good flexibility. 3 ... Flexibility is normal. 2 ... Poor flexibility. 1 ... very poor flexibility. (6) Tensile strength: Performed according to the method shown in JIS P 8113.

Example 2 Polybutylene succinate having a melt flow rate of 30
80% of polymer (trade name: Bionore, manufactured by Showa High Polymer Co., Ltd.)
And the melt flow rate is 40, and the content of adipic acid is 1
0 mol% polybutylene succinate / adipate
Compound (trade name: Bionore, manufactured by Showa Polymer Co., Ltd.) 20%
Were mixed to prepare a mixed resin. Using this mixed resin
To form a long-fiber nonwoven web in the same manner as in Example 1.
I let you. The fineness of the long fiber was 2.2 denier. next,
This long-fiber web is heated to 90 ° C.
The part that is introduced between the rolls and corresponds to the convex part of the uneven roll
Is fused to give a basis weight of 12 g / m ^TwoLong fiber non-woven
Got the cloth. The linear pressure of the roll is 20 kg / cm.
The area of each self-fused area is 1.0 mm^TwoAnd
The total area of the self-bonding area is 15 per nonwoven fabric area
%. The obtained long-fiber nonwoven fabric was subjected to the test method described above.
And evaluated its quality.

Example 3 Polybutylene succinate having a melt flow rate of 50
60% of polymer (trade name: Bionore, manufactured by Showa High Polymer Co., Ltd.)
And the melt flow rate is 40, and the content of adipic acid is 3
0 mol% polybutylene succinate / adipate
Compound (trade name: Bionore, manufactured by Showa High Polymer Co.) 40%
Were mixed to prepare a mixed resin. Using this mixed resin
To form a long-fiber nonwoven web in the same manner as in Example 1.
I let you. The fineness of the long fiber was 4.4 denier. next,
This long-fiber web is heated to 90 ° C.
The part that is introduced between the rolls and corresponds to the convex part of the uneven roll
Is fused to give a basis weight of 12 g / m ^TwoLong fiber non-woven
Got the cloth. The linear pressure of the roll is 20 kg / cm.
The area of each self-fused area is 1.0 mm^TwoAnd
The total area of the self-bonding area is 15 per nonwoven fabric area
%. The obtained long-fiber nonwoven fabric was subjected to the test method described above.
And evaluated its quality.

Example 4 Polybutylene succinate having a melt flow rate of 65
85% of polymer (trade name: Bionore, manufactured by Showa High Polymer Co., Ltd.)
And the melt flow rate is 50, and the content of adipic acid is 1
0 mol% polybutylene succinate / adipate
Compound (trade name: Bionore, manufactured by Showa High Polymer Co.) 15%
Were mixed to prepare a mixed resin. Using this mixed resin
To form a long-fiber nonwoven web in the same manner as in Example 1.
Was. The fineness of the long fiber was 2.1 denier. Next,
Roll and smooth roll of long fiber web heated to 85 ° C
Roll, and adjust the part corresponding to the convex part of the uneven roll.
By fusing, the basis weight is 24 g / m ^TwoLong fiber non-woven fabric
I got The linear pressure of the roll is 30 kg / cm
The area of each self-fusion zone is 0.28 mm^TwoAnd
Total area of self-bonding area is 8 areas per total area of non-woven fabric
%Met. The obtained long-fiber nonwoven fabric is subjected to the above-described test method.
Tested and evaluated its quality.

COMPARATIVE EXAMPLE 1 The proportion of the mixed resin was changed to a polybutylene succinate polymer 95
% And polybutylene succinate / adipate copolymer 5
%, And a long-fiber nonwoven fabric was manufactured in the same manner as in Example 1 except that the mixed resin was used. The obtained long-fiber nonwoven fabric was tested by the test method described above, and its quality was evaluated.

Comparative Example 2 The ratio of the mixed resin was changed to polybutylene succinate polymer 30.
% And polybutylene succinate / adipate copolymer 7
A long-fiber nonwoven fabric was manufactured in the same manner as in Example 1 except that the mixed resin with 0% was used. The obtained long-fiber nonwoven fabric was tested by the test method described above, and its quality was evaluated.

Comparative Example 3 The procedure of Example 1 was repeated except that the polybutylene succinate-adipate copolymer used had a content of adipic acid of 40 mol% (trade name: Bionole, manufactured by Showa Polymer Co., Ltd.). Similarly, a long-fiber nonwoven fabric was manufactured. The obtained long-fiber nonwoven fabric was tested by the test method described above, and its quality was evaluated.

Comparative Example 4 The procedure of Example 1 was repeated except that a resin mixture of a polybutylene succinate polymer having a melt flow rate of 5 and a polybutylene succinate-adipate copolymer having a melt flow rate of 10 was used. An attempt was made to produce a long-fiber nonwoven fabric, but the yarn was frequently broken during spinning, and spinning was not possible.

Comparative Example 5 A long-fiber nonwoven fabric was produced in the same manner as in Example 1, except that the fineness of the long fiber was changed to 12 denier. The obtained long-fiber nonwoven fabric was tested by the test method described above, and its quality was evaluated.

Table 1 shows the results obtained in Examples and Comparative Examples.

[0031]

[Table 1]

As is clear from Table 1, the present invention is excellent in flexibility, formation and strength, has biodegradability, and
A long-fiber nonwoven fabric having a controlled biodegradation rate within a range of 12 months is obtained (Examples 1 to 4). On the other hand, in the case of a mixed resin having a low content of easily decomposable polybutylene succinate-adipate copolymer, flexibility, formation,
Although other properties such as strength and spinnability are excellent, the biodegradation rate is slow (Comparative Example 1). Conversely, the decomposition rate is 2 in the case of a mixed resin having a high content of polybutylene succinate-adipate copolymer. Although it was very short and excellent in strength as in a month, the spinnability, flexibility and formation were poor and a good nonwoven fabric could not be produced (Comparative Example 2). When a polybutylene succinate-adipate copolymer having a high content of adipic acid was used, the spinnability was poor, and the nonwoven fabric was poor in flexibility and formation (Comparative Example 3). When a resin having a too low melt flow rate was used, the spinnability became extremely poor, and a nonwoven fabric could not be produced (Comparative Example 4). If the fiber diameter is too large, the flexibility becomes extremely poor, making it unpractical (Comparative Example 5).

[0033]

According to the present invention, there is provided a long-fiber nonwoven fabric having excellent formation, flexibility, strength and spinnability, decomposability by microorganisms, and capable of easily controlling the decomposition rate, and a method for producing the same. It works.

Claims (4)

[Claims] 1. A thermoplastic aliphatic polyester resin is heated and melted, extruded and spun from a die of an extrusion spinning machine, and a spun continuous filament filament group is drawn by high-speed air from an ejector, charged and opened. After the fibers are collected, collected and accumulated on a support to form a web, the web is partially thermocompression-bonded, and in a biodegradable long-fiber nonwoven fabric, the resin constituting the long fibers is 1,4- Polybutylene succinate polymer synthesized from butanediol and succinic acid 50-
90% by weight of polybutylene succinate synthesized from 1,4-butanediol and succinic acid and adipic acid
A biodegradable long-fiber nonwoven fabric comprising a mixed resin containing 50 to 10% by weight of an adipate copolymer. 2. A thermoplastic aliphatic polyester resin is heated and melted, extruded and spun from a die of an extrusion spinning machine, and a spun continuous filament filament group is drawn by high-speed air from an ejector, charged and opened. In a method for producing a biodegradable long-fiber nonwoven fabric, the web is formed by collecting and accumulating on a support to form a web, and then partially thermocompressing the web. , 4-
50-90% by weight of a polybutylene succinate polymer synthesized from butanediol and succinic acid, and 50-1% by weight of a polybutylene succinate-adipate copolymer synthesized from 1,4-butanediol, succinic acid and adipic acid
A method for producing a biodegradable long-fiber nonwoven fabric, characterized in that 0% by weight is used as a mixture. 3. The JIS K 721 of the thermoplastic resin
3. The raw material according to claim 2, wherein the melt flow rate according to 0 is in the range of 15 to 80 g / 10 minutes, and the difference between the respective melt flow rates of the resin before mixing is in the range of 0 to 20. A method for producing a degradable long-fiber nonwoven fabric. 4. The method for producing a biodegradable long-fiber nonwoven fabric according to claim 2, wherein the content of adipic acid in the polybutylene succinate-adipate copolymer is 5 to 35 mol%.