WO2006129731A1

WO2006129731A1 - Biodegradable polyester fiber

Info

Publication number: WO2006129731A1
Application number: PCT/JP2006/310930
Authority: WO
Inventors: Shoji Obuchi; Takayuki Kuroki; Shigeyuki Motomura; Hisashi Morimoto
Original assignee: Mitsui Chemicals, Inc.
Priority date: 2005-06-01
Filing date: 2006-05-31
Publication date: 2006-12-07
Also published as: JP4409601B2; JPWO2006129731A1

Abstract

A biodegradable polyester fiber, nonwoven fabric and sanitary goods from the nonwoven fabric that excel in flexibility and thermal shrinkage resistance. There is provided a biodegradable polyester fiber comprised of biodegradable polyester composition (C) containing 70 to 99 parts by weight of biodegradable polyester (A) and 30 to 1 parts by weight (the sum of components (A) and (B) being 100 parts by weight) of modification material (B) of a specified ester compound. Further, there is provided a biodegradable polyester nonwoven fabric comprised of the above biodegradable polyester fiber.

Description

Specification

Biodegradable polyester fiber

Technical field

[0001] The present invention relates to a biodegradable polyester fiber comprising a biodegradable polyester composition that is degradable in a natural environment, a nonwoven fabric comprising the fiber, and a sanitary article comprising the nonwoven fabric. More specifically, a biodegradable polyester composition containing a biodegradable polyester and a modifying material is prepared, and a biodegradable polyester fiber excellent in flexibility and heat shrinkage, a non-woven fabric comprising the fiber, It relates to sanitary goods made of non-woven fabric.

Background art

[0002] Conventionally, as a fiber having degradability and a nonwoven fabric made of the fiber, for example, cotton, hemp, wool, rayon, chitin, which are biodegradable fibers derived from natural fibers or regenerated fibers, Alginic acid and other fibers and nonwovens are known! /

[0003] However, since these fibers and non-woven fabrics that also have biodegradable material strength generally have hydrophilicity and water absorption properties, they have hydrophobicity and low water absorption properties, such as top sheets of disposable diapers. It is not suitable for applications that require a dry feeling when wet. In addition, these fibers and non-woven fabrics have a limit in their development as general industrial materials, where the decrease in strength and dimensional stability in a wet environment is significant. Furthermore, since these fibers are non-thermoplastic, they do not have thermoformability and are inferior in processability.

[0004] Therefore, in recent years, research and development on biodegradable fibers and non-woven fabrics by melt spinning using thermoplastic and hydrophobic biodegradable polymers has become active. For example, various attempts have been made to make polylactic acid into fibers and non-woven fabrics. In particular, polylactic acid is useful in applications requiring heat resistance with a relatively high melting point among biodegradable polyesters, and therefore, practical application of polylactic acid nonwoven fabric is expected.

[0005] As a non-woven fabric using polylactic acid, JP-A-7-126970 (Patent Document 1) discloses a short-fiber non-woven fabric mainly composed of polylactic acid. JP-A-6-212511 (Patent Document 2) discloses polylactic acid short fibers useful for the production of short fiber nonwoven fabrics. However, non-woven fabric made of polylactic acid is not flexible enough. In addition, since heat resistance is not sufficient as compared with nonwoven fabrics such as polypropylene, its use is limited.

[0006] For the development of a material provided with flexibility by adding an additive such as a plasticizer to polylactic acid, for example, JP-A-2003-292474 (Patent Document 3) discloses a specific ester compound. An example of using as a plasticizer has been disclosed, but it has been disclosed to apply this material to fibers and non-woven fabrics.

Patent Document 1: JP-A-7-126970

Patent Document 2: JP-A-6-212511

Patent Document 3: Japanese Patent Laid-Open No. 2003-292474

Disclosure of the invention

Problems to be solved by the invention

[0007] An object of the present invention is to provide a biodegradable polyester fiber excellent in flexibility and heat shrinkage resistance, a nonwoven fabric, and a sanitary article comprising the nonwoven fabric.

Means for solving the problem

[0008] The biodegradable polyester fiber according to the present invention comprises a biodegradable polyester (A) 70 to 99 parts by weight and a modifier (B) 30 to 1 part by weight (however, (A) and (B) Total 100 parts by weight

), And the modifying material (B) is an ester compound represented by the following general formula (1).

[0009] [Chemical 1]

R ¹ OOC― (CH ₂ ) _m — COOR ² … ₍₁₎

[Wherein, R ¹ and R ² are different from each other and each represents a group represented by the following general formula (2), and m represents an integer of 0 to 8.]

[0011] [Chemical 2]

— (R ³ 0) _n R ⁴ _... ₍₂₎

(In the formula, R ³ represents an alkylene group having 1 to 6 carbon atoms, R ⁴ represents a linear or branched alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a carbon number. 7 to 15 ary reels Or an alkylaryl group having 7 to 15 carbon atoms, and n represents an integer of 0 to 6. The biodegradable polyester fiber of the present invention preferably has a heat shrinkage rate at 130 ° C. of 10% or less.

[0013] The biodegradable polyester (A) is preferably a lactic acid series resin, more preferably a polylactic acid. The biodegradable polyester composition (C) comprises a decomposition accelerator (D) 1 to 20 parts by weight with respect to 100 parts by weight of the total amount of the biodegradable polyester (A) and the modifier (B). It may also be included.

[0014] The biodegradable polyester nonwoven fabric according to the present invention is characterized by comprising the biodegradable polyester fiber cable of the present invention.

[0015] The biodegradable polyester nonwoven fabric of the present invention has a longitudinal softness of QilS L1096 (MD).

It is preferable that the total of the A method (according to 45 ° cantilever method) described in 8.9.1 and the bending resistance in the transverse direction (CD) [conforms to the same method] is 100 mm or less. Also, the longitudinal direction (MD

) Is more preferably 60 mm to 0 mm, and the transverse (CD) bending resistance is more preferably 40 mm to 0 mm.

[0016] The sanitary article according to the present invention is the biodegradable polyester nonwoven fabric according to the present invention, and examples thereof include sanitary napkins, panty liners, disposable disposable diapers, and sanitary tampon applicators.

The invention's effect

[0017] According to the present invention, a biodegradable polyester fiber, a nonwoven fabric, and a sanitary article comprising the nonwoven fabric that are biodegradable and have practically sufficient flexibility and heat-resistant / condensation stability can be obtained.

BEST MODE FOR CARRYING OUT THE INVENTION

[0018] Hereinafter, the biodegradable polyester fiber according to the present invention, the biodegradable polyester nonwoven fabric made of the fiber capsule, and the sanitary article also having the nonwoven fabric power will be described in detail.

[Biodegradable polyester fiber]

The biodegradable polyester fiber according to the present invention comprises a biodegradable polyester composition (C) containing a biodegradable polyester (A), a modifying agent (B), and a degradation accelerator (D) as necessary. The resulting fiber. [0020] <Biodegradable polyester (A)>

The biodegradable polyester (A) used in the present invention is, for example, a hydroxycarboxylic acid, an aliphatic polyhydric alcohol, an aromatic polyhydric alcohol, an aliphatic polycarboxylic acid, or an aromatic polyvalent carboxylic acid selected from one kind Alternatively, two or more types of aliphatic polyester or aromatic polyester that are biodegradable thermoplastic resin.

[0021] The biodegradable polyester (A) can take any form of a homopolymer or a copolymer (random, block, comb-shaped, etc.). For example, polylactic acid-based resin, polyethylene succinate-based resin, polyethylene succinate adipate-based resin, polybutylene succinate-based resin, polybutylene succinate adipate-based resin, polybutylene succinate carbonate-based resin, Examples include polyethylene carbonate resin, polyethylene terephthalate adipate resin, polybutylene succinate terephthalate resin, polybutylene adipate terephthalate resin S, poly-prolatatone resin S, polyglycolene acid resin It is done.

[0022] In particular, the polylactic acid-based resin described below, as well as polylactic acid, poly-strength prolatatone, polybutylene succinate, polybutylene succinate adipate, polybutylene terephthalate adipate and polyethylene terephthalate adipate are already commercially available and inexpensive. It is preferable because it is easily available.

[0023] The monomer units constituting them may be chemically modified or a copolymer of different monomers. In addition, hydroxycarboxylic acids such as glycolic acid and 3-hydroxybutyric acid; polyvalent carboxylic acids such as succinic acid and adipic acid; polysaccharides such as cellulose acetate and ethylcellulose; and polyhydric alcohols such as ethylene glycol and diethylene glycol. It may be a copolymer of a species or two or more species and a mixture of monomers constituting the above-mentioned rosin. Further, for example, starch-based resin, chitosan-based resin, polyvinyl alcohol-based resin, or petroleum-based resin can be blended within the range not impairing the object of the present invention.

[0024] The biodegradable polyester (A) has a weight average molecular weight (Mw) of preferably 60,000 to 1,000,000, more preferably 80,000 to 500,000, particularly preferably 100,000 to 300,000. Is. Generally, when the weight average molecular weight (Mw) is less than 60,000, the molded product obtained by molding the resin composition has sufficient mechanical properties, and conversely the molecular weight exceeds 1 million. In some cases, the melt viscosity at the time of molding becomes extremely high, making it difficult to handle or making it uneconomical in production.

Similarly, the molecular weight distribution (MwZMn) is not particularly limited as long as it can be substantially molded and exhibits substantially sufficient mechanical properties, but generally 1.5 to 8 is preferable. 2-6 are more preferred 2-5 are particularly preferred.

[0026] The polylactic acid-based resin in the present invention means a polymer composition mainly composed of a polymer containing lactic acid units of 50% by weight or more, preferably 75% by weight or more, As the lactic acid used for the raw material, L-lactic acid, D-lactic acid, DL-lactic acid, a mixture thereof or lactide which is a cyclic dimer of lactic acid can be used.

[0027] The constitution of the lactic acid unit in the polylactic acid-based rosin includes L lactic acid, D lactic acid, and a mixture thereof, and can be appropriately selected depending on the application.

[0028] When polylactic acid containing L-lactic acid as a main component is used as the polylactic acid-based resin, D-lactic acid: L? L acid = 0. 1: 99.9-30: 70 Preferable, 0.1: 99.9-15: 85 More preferable than force S, more preferably 0.1: 99.9-6: 94 S 0.1: 99.9 to 2:98 is particularly preferable.

[0029] On the other hand, when polylactic acid containing D-lactic acid as the main component is used, L-lactic acid: D-lactic acid = 1:99 to 30:70. : 85 is preferable, 0.1: 99.9-6: 94 is more preferable, and 0.1: 99.9-2: 98 is particularly preferable.

[0030] It is also possible to blend two or more types of polylactic acid having different constituent ratios of D-lactic acid and L-lactic acid.

[0031] As a method for producing the biodegradable polyester (A), a known method is used. In the case of polylactic acid-based fats preferably used in the present invention, for example,

(1) A method of direct dehydration polycondensation using lactic acid or a mixture of lactic acid and aliphatic hydroxycarboxylic acid as a raw material (see, for example, US Pat. No. 5,310,865),

(2) a ring-opening polymerization method in which a cyclic dimer (lactide) of lactic acid is melt-polymerized (see, for example, US Pat. No. 2,758,987),

(3) Cyclic dimer of lactic acid and aliphatic hydroxycarboxylic acid (e.g. Ring-opening polymerization method in which melt polymerization is performed in the presence of a catalyst (see, for example, US Pat. No. 4,057,537),

(4) A method of directly dehydrating polycondensation of a mixture of lactic acid, aliphatic dihydric alcohol and aliphatic dibasic acid (see, for example, US Pat. No. 5,428,126),

(5) a method of condensing a polymer of polylactic acid, an aliphatic dihydric alcohol and an aliphatic dibasic acid in the presence of an organic solvent (see, for example, European Patent Publication 0712880A2),

(6) A method of performing solid-phase polymerization in at least a part of the steps when producing a polyester polymer by performing a dehydration polycondensation reaction of lactic acid in the presence of a catalyst.

It is not limited to these.

[0032] In addition, a small amount of an aliphatic polyhydric alcohol such as trimethylolpropane or glycerin, an aliphatic polybasic acid such as butanetetracarboxylic acid, or a polyhydric alcohol such as a polysaccharide can coexist. It may be polymerized, or the molecular weight may be increased by using a binder (high molecular chain extender) such as diisocyanate compound.

[0033] The biodegradable polyester (分解) is particularly preferably polylactic acid, more preferably polylactic acid-based rosin.

[0034] <Modifier)>

The modifier (Β) used in the present invention is an additive that imparts flexibility and heat shrinkage resistance by being added to the biodegradable polyester (Α), and is an ester represented by the following formula (1). A compound.

[0035] [Chemical 3]

R ¹ OOC— (CH ₂ ) _m — COOR ² … ₍₁₎

In the formula (1), R ¹ and R ² are different from each other and each represents a group represented by the following general formula (2), and m represents an integer of 0 to 8.

[0037] [Chemical 4]

— (R ³ 0) _n R ⁴ _... ₍₂ )

[0038] In the formula (2), R ³ represents an alkylene group having 1 to 6 carbon atoms, and R ⁴ is a straight chain having 1 to 10 carbon atoms. Represents a branched alkyl group, an aryl group having 6 to 12 carbon atoms, an aryl group having 7 to 15 carbon atoms or an alkylaryl group having 7 to 15 carbon atoms, and n represents an integer of 0 to 6.

[0039] Examples of the dibasic acid used as a raw material for the ester compound include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid. . Of these, succinic acid or adipic acid is preferred.

[0040] Examples of the alcohol used as a raw material for the ester compound include, for example, methanol, ethanol, 1 propanol, 2-propanol, 1-butanol, 2-butanol, 2-methylolene 1 propanol, 1, 1-dimethanol, 1 ethanol and pentano. Nore, hexanol, heptanol, octanol, phenol, benzyl alcohol, phenethyl alcohol and the like. Among these, methanol, ethanol, 1-propanol, 1-butanol, pentano, hexanol, heptanol, octanol, benzyl alcohol and phenethyl alcohol are preferred. Nord, octanol and phenethyl alcohol are more preferred.

[0041] Examples of the ether alcohol used as the raw material for the ester compound include the ethylene oxide adducts and propylene oxide adducts of the above alcohols. Specifically, ethylene glycol monomethyl ether, ethylene glycol monoethyl etherate, ethylene glycol monobutino enoate, ethylene glycol monomono enoenoate, ethylene glycol monomono enoenoate, diethylene glycol monole. Monomethylol etherenole, diethyleneglycolenomonochinoleetenore, diethyleneglycolanolenobutinoylenotenole, diethyleneglycolenomonophenolatenore, diethyleneglycolanolenomonobenzyl ether, triethyleneglycolmonomethylether, triethyleneglycolmonoethyl Ether, triethylene glycol monobutyl ether, triethylene glycol monophenol mono-ethanolate, triethylene glycol mono-mono ether Ethylene oxide-attached products such as ginoleatenole; propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol Noremonomethinoreethenore, Dipropyleneglycolenorethinoreatenore, Dipropyleneglycolenoremonobutinoreether, Dipropyleneglycolenoremonophenol ether, Dipropylene glycol monovinyl ether ether, tripropylene glycol monomer mono ether ether, tripropylene glycol monomer monomer ether, tripropylene glycol monomer monomer alcohol, tripropylene glycol monomer monomer ether, Examples include propylene oxide adducts such as tripropylene glycol monobenzil ether.

[0042] Of these, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutino ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, and triethylene glycol monobutyl ether are preferred. More preferred are diethylene glycol monomethyl ether, jetylene glycol monomethino ether, and diethylene glycol monobutino ether.

[0043] Examples of the compound obtained by reacting the dibasic acid with alcohol or ether alcohol include methyl diglycol butyl diglycol adipate, benzyl methyl diglycol adipate, and benzyl butyl diglycol adipate. .

[0044] As the modifying material (B), an ester compound available from Kayaba Co., Ltd. may be used. As an example of what can be obtained from Kayaba, the trade name: Daifati-101-101 (manufactured by Daihachi Chemical Industry Co., Ltd.) can be mentioned. These modifiers can be used alone or in combination of two or more.

[0045] The number average molecular weight (Mn) of the ester compound is not particularly limited! In general, the smaller the molecular weight, the greater the reforming effect, but the lower the stability, the surface of the molded product is blocked by bleeding out. In addition, the possibility of occurrence of contamination increases. Therefore, the number average molecular weight (Mn) of the ester compound is preferably about 200 to 1500, more preferably about 300 to 1000.

[0046] <Biodegradable polyester composition (C)>

The biodegradable polyester composition (C) used in the present invention is a resin composition containing the biodegradable polyester (A) and the modifier (B). The content of the biodegradable polyester (A) in the composition (C) is 70 to 99 parts by weight, preferably 75 to 95 parts by weight, more preferably 80 to 90 parts by weight. ) Content is 30-1 parts by weight, preferably 25 to 5 parts by weight, more preferably 20 to: LO parts by weight (provided that the sum of (A) and (B) is 100 parts by weight).

[0047] The biodegradable polyester composition (C) has various additives other than the modifier (B), for example, a plasticizer, a compatibilizer, and the like, within a range not impairing the object of the present invention. Antioxidants, lubricants, colorants, ultraviolet absorbers, light stabilizers, pigments, inorganic fillers and the like may be added as additional components.

[0048] In addition, the biodegradable polyester composition (C) includes a resin other than the biodegradable polyester (A) within a range not impairing the object of the present invention, such as polypropylene, polyethylene, polyethylene, and the like. You can also add as an additional ingredient a fat that is made from fossil resources such as salty vinyl!

[0049] Decomposition accelerator (D)>

Since the nonwoven fabric made from the biodegradable polyester composition of the present invention has biodegradability, when it is discarded after use as a sanitary product, it is degraded in compost or soil. As a result, the load on the landfill will be reduced. In particular, when sanitary products are thrown into the toilet and reach the sewage treatment plant, they are collected and collected in a sand settling tank or activated sludge collection tank, and finally transported to the sludge treatment plant (landfill). It is preferable to decompose and disappear effectively.

[0050] The shorter the biodegradation period of the non-woven fabric made of the biodegradable polyester composition, the better the landfill volume is reduced. The nonwoven fabric of the present invention made mainly of polylactic acid disappears in the earth for several years. However, it is preferable to contain a decomposition accelerator in order to further shorten the decomposition period of polylactic acid. By including a decomposition accelerator, the decomposition period is 1 to 6 months. If the addition amount is increased, the decomposition period is shortened, but the physical properties of the nonwoven fabric may be impaired. Therefore, the addition amount may be appropriately selected according to the use.

[0051] The addition amount of the decomposition accelerator is preferably 1 to 20 parts by weight, more preferably 2 to L0 parts by weight, and particularly preferably 3 to 7 parts by weight with respect to 100 parts by weight of the biodegradable polyester composition. is there.

[0052] The degradation accelerator (D) used as necessary in the present invention has an action of promoting the degradation of the biodegradable polyester composition (C). Specifically, the degradation accelerator (D) is hydrophilic. It has polyamino acid as segment (d-1) and biodegradable as hydrophobic segment (d-2) A block or graft copolymer having polyester.

[0053] In the present invention, the hydrophobic segment is a degradable polyester that is hardly soluble or insoluble in water or a segment induced by the force, and is more hydrophobic than the other hydrophilic segment. In addition, a hydrophilic segment is a polymer that is soluble in water or a segment derived therefrom, or a polymer that is sparingly soluble in water but more hydrophilic than the hydrophobic segment or its force. It is a segment.

[0054] The hydrophilic segment (d-1) in the decomposition accelerator (D) is not particularly limited as long as it contains a polyamino acid in the segment, but it is preferably aspartic acid. More preferably, the constituent unit derived from aspartic acid is contained as 1 mol% or more, preferably 10 mol% or more of the total amount of the hydrophilic segment. Particularly preferably, the hydrophilic segment also has a structural unit force derived from aspartic acid.

[0055] The hydrophobic segment (d-2) is not particularly limited as long as it contains a degradable polyester in the segment, but it is preferably derived from an aliphatic polyester. More preferably, it contains 1 mol% or more, preferably 10 mol% or more of the total amount of the lactic acid-derived structural unit, particularly preferably hydrophobic. The sex segment can also be a structural unit derived from lactic acid.

[0056] The preferred form of the above-described degradation accelerator (D) is a structural unit derived from aspartic acid as a hydrophilic segment (d-1) and a biodegradable as a hydrophobic segment (d-2) in the structure. A structural unit derived from a polyester (hereinafter referred to as a structural unit derived from a hydrophobic segment (d-2)) coexists. The copolymer contains 1 mol% or more of structural units derived from aspartic acid of the hydrophilic segment (d-1) and 1 mol% or more of structural units derived from the hydrophobic segment (d-2). U, who prefers to be included.

[0057] In the decomposition accelerator (D), the composition ratio of the aspartic acid-derived unit of the hydrophilic segment (d-1) and the unit derived from the hydrophobic segment (d-2) is not particularly limited. The force is preferably 1Z1 to 1Z50.

[0058] The copolymer constituting the decomposition accelerator (D) contains a hydrophilic segment (d-1) class. Constituent elements other than normal acid and hydrophobic segment (d-2) may be present by copolymerization. However, the amount must be such that the properties of the decomposition accelerator (D) are not significantly impaired. Considering the points to be worked out, the amount is about 20 mol% or less.

Note that aspartic acid is a force that generates a polymer having succinimide units by dehydration condensation, and the structural unit derived from aspartic acid means to include succinimide units. Further, the aspartic acid unit contained in the structure of the decomposition accelerator (D) can be a mixture of an a-amide type monomer unit and an —amide type monomer unit, and the ratio of both is not particularly limited.

[0060] The decomposition accelerator (D) is obtained by copolymerization reaction of aspartic acid and hydroxycarboxylic acids, lactides or latatones, and the production method thereof is not particularly limited. In general, it can be obtained by mixing aspartic acid and hydroxycarboxylic acids in a desired ratio and superposing them under heating.

[0061] Regarding the molecular weight of the decomposition accelerator (D), the weight-average molecular weight (Mw) can be mixed with the biodegradable polyester composition (C) satisfactorily to increase the effect of promoting decomposition. However, preferred <is 1000 to 100,000, more preferred <2000 to 50,000.

[0062] The hydrophilic segment (d-1) and the hydrophobic segment (d-2) constituting the decomposition accelerator (D) can be used without any problem regardless of the configuration of the block or graft copolymer. wear.

[0063] <Method for preparing composition (C)>

In the present invention, the method of mixing the biodegradable polyester (A) and the modifier (B), and, if necessary, the degradation accelerator (D) and other additives is not particularly limited! A method of stirring by heating and melting or dissolving in a solvent is preferred. For example, biodegradable polyester (A), modifier (B), and degradation accelerator (D) and other additives, if necessary, are mixed using a Henschel mixer, super mixer, tumbler type mixer, etc. After that, continuous kneading is performed using a single screw or twin screw extruder. Here, in order to further improve the dispersibility of the biodegradable polyester (A) and the modifier (B), and the degradation accelerator (D) and other additives used as necessary, a twin-screw extruder is used. Is preferred.

<Method for producing biodegradable polyester fiber> As a method for obtaining the biodegradable polyester fiber according to the present invention, a known spinning method is applied, and single spinning or composite spinning may be used. Particularly, the composite spinning forms include core-sheath type and parallel type composite spinning. It is done. A specific spinning method includes a melt spinning method in which the composition (C) is melt-spun using an extruder; the composition (C) is dissolved in a solvent to form a solution; In addition, a wet spinning method in which the solution is discharged into a poor solvent; a dry spinning method in which the solution is discharged from a nozzle into a dry gas, and the like can be given. In the melt spinning method, a known extruder such as a single screw extruder or a twin screw extruder can be used. The diameter of the nozzle (nozzle) of the extruder is a force that is appropriately determined according to the relationship between the required fiber diameter (thread diameter) and the discharge speed and take-off speed of the extruder, preferably 0.1 to 3. About Omm.

[0065] In any of the above spinning methods, it is not always necessary to stretch the fiber after spinning. When force stretching is performed: 1. The fiber is stretched 1 to 20 times, preferably 2 to 15 times. The preferred yarn diameter of the fiber is 0.5 to 40 denier.

[0066] The fibers of the present invention have an average fiber diameter of 7 µm to 40 µm, preferably 10 µm to 37 µm, more preferably 12 µm to 35 µm. When the average fiber diameter is in the above range, the spinnability and strength are excellent.

[0067] The heat shrinkage force at 130 ° C of the fiber of the present invention is preferably 10% or less, more preferably 8% or less, and further preferably 5% or less. When the thermal shrinkage rate is 10% or less, it is easy to produce a product with almost no shrinkage during aging mold processing, etc., and even in usage forms exposed to high temperature environments close to 100 ° C Excellent.

[0068] [Biodegradable polyester nonwoven fabric]

The biodegradable polyester nonwoven fabric of the present invention comprises the biodegradable polyester fiber of the present invention. The single fiber or the composite fiber constituting the nonwoven fabric of the present invention can be appropriately selected depending on the purpose of use, which may be either a long fiber or a short fiber.

[0069] Examples of the method for producing the nonwoven fabric of the present invention include known methods that are not particularly limited, such as a dry method, a spun bond method, a melt blow method, and a wet method. That is, it is obtained by spinning the biodegradable polyester composition (C) by the above method, forming a lump state of fibers called a web, and bonding the web by a conventionally known method.

[0070] The web production method is not particularly limited, and a known method can be adopted. The For example, a card type using a flat card machine, a roller card machine, a garnet machine, etc., a melt blow type and the like can be mentioned. Also, when spinning fiber, spunbond type, in which high-speed air is blown when fibers come out from the nozzle of the spinning machine and collected on a perforated conveyor perpendicular to the airflow to form a web.

[0071] As a method for obtaining the biodegradable nonwoven fabric of the present invention from the web strength obtained as described above, a known method can be employed. For example, entanglement with a needle-one-dollar punch method, stitch bond method with entanglement with yarn, spunlace method with water flow, jet bond method, thermal bond method with heat bonding, chemical bond method with adhesive, resin bond Law.

[0072] basis weight of the nonwoven fabric of the present ^{invention, lg / m 2 ~50g / m} 2, preferably ^{^{7g / m 2 ~50g / m 2}} , more preferably 1 OgZm ^² ~40gZm ^2, more preferably 12 g / m ² it is a ~ 30g / m ^2. When the basis weight is in the above range, the gap between the fibers is moderate, and the packaging property, shielding property and holding property are excellent.

[0073] The nonwoven fabric of the present invention has a longitudinal (MD) bending resistance QilS L1096 of A Method described in 8.19.1

(Compliant with 45 ° cantilever method) and lateral (CD) bending resistance [Compliant with the same method] Force preferably 100 mm to Omm, more preferably 90 mm to Omm, particularly preferably 80 mm to Omm. When the bending resistance is in the above range, the flexibility is excellent. The lower the bending resistance, the better the flexibility.

[0074] The bending resistance in the machine direction (MD) is preferably 60mn! ~ Omm, more preferably 50 mn! ˜Omm, particularly preferably 40 mm to 0 mm, and the bending resistance in the transverse direction (CD) is preferably 40 mm to 0 mm, more preferably 30 mm to Omm, particularly preferably 20 mm to 0 mm.

[0075] Preferred forms of the nonwoven fabric of the present invention are those in which the constituent fibers are entangled and integrated by hydroentanglement treatment, etc., those in which the fiber intersections are thermally fused and integrated by hot air treatment or the like, For example, it may be integrated by having a partial thermocompression bonding part by partial thermocompression treatment. Among these, those that are partially thermocompression bonded and retain the form as a nonwoven fabric are preferred from the standpoint of strength. Partially heat-bonded non-woven fabric is bonded only at the point-like fused area, so it has both flexibility and form retention. It becomes a non-woven fabric that is soft and difficult to fluff.

[0076] Here, the partial thermocompression bonding refers to forming a spot-like fusion zone by embossing or ultrasonic fusion treatment. Specifically, the heated embossing roll and the surface are smooth. There is a method of forming a dotted fused area between fibers through a web between the rolls, or a method of forming a dotted fused area between fibers in a pattern portion by applying a high frequency by ultrasonic waves on a pattern roll. is there.

[0077] [Usage]

Examples of suitable molded articles of the biodegradable polyester fiber according to the present invention include knitted fabrics, woven fabrics, non-woven fabrics, nets, ropes, and other various molded articles, and suitable biodegradable polyester nonwoven fabrics according to the present invention. Applications include hygiene products, living materials, agricultural materials, and civil engineering materials.

[0078] A sanitary article can be produced by adhering and fixing the biodegradable polyester fiber or nonwoven fabric according to the present invention to each other by a known method such as hot melt bonding or heat bonding. Examples of sanitary products include sanitary tampon applicators, sanitary napkins, panty liners, disposable paper diapers, and incontinence pads.

[0079] By using the biodegradable polyester fiber or nonwoven fabric of the present invention, a sanitary article having biodegradability and practically sufficient flexibility and heat shrinkage stability can be obtained.

[0080] [Example]

EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not limited to these Examples. In addition, various measurements such as physical properties in Examples and the like 'evaluation methods are as follows.

[0081] <Mechanical strength>

All the procedures other than those shown below were measured in accordance with JIS L 1906.

1) Five test pieces (width 25 mm, length 200 mm) were collected from the nonwoven fabric in the machine direction (MD) and the transverse direction (CD), respectively.

2) A tension test was performed on each collected specimen using a tensile tester (type 5564 manufactured by Instron Co., Ltd.) under the conditions of 100 mm between the chucks and a tensile speed of lOOmmZmin. Test piece breaks The maximum load value (NZ25mm) shown up to was measured, and the average value was calculated. In addition, the elongation at the maximum load was defined as the maximum tensile elongation (%), and the average value was calculated.

[0082] <Amount of basis weight>

Ten test pieces of 100 mm × 100 mm were cut out from the nonwoven fabric, measured according to JIS L1906, and converted to g / m ² .

[0083] <Bending softness>

The bending resistance of the nonwoven fabric was measured in accordance with Method A (45 ° cantilever method) described in JIS L1096, 8.1. Specifically, 3 pieces of 2 cm × 15 cm specimens were collected from the nonwoven fabric in the machine direction (MD) and the transverse direction (CD), respectively. The short side of the test piece was placed on the scale base line on a smooth horizontal surface with a 45 ° slope at one end. Next, the specimen was gently slid in the direction of the slope by an appropriate method, and the position of the other end was read with a scale when the central point of the edge of the specimen was in contact with the slope. The bending resistance was indicated by the length (mm) that the specimen moved, and we measured three samples each, calculated the average value in the vertical and horizontal directions, and rounded them to whole numbers.

[0084] <Heat shrinkage rate>

1) A dividing line with a clearance of 100mm was made on a piece of paper with a smooth surface and gloss. A bundle of fibers taken out from the non-woven fabric before being heated and pressurized with an embossing roll was placed on a piece of paper and both ends were affixed and fixed with tape. One end of the fiber was cut to obtain a bundle of 100 mm long fibers.

2) This sample was heated in a dryer (130 ° C) for 1 minute.

3) Measure the length of the fiber after heating, {(length before heating (100mm) —length after heating) Z length before heating (100mm)} X 100 (%) The value was defined as the heat shrinkage rate.

[0085] <Fiber diameter>

Measured with an optical microscope, the average value at 10 locations was taken as the fiber diameter.

[0086] <Bleed test>

A 10 cm × 10 cm test piece was taken from the non-woven fabric and aged at 80 ° C. for 24 hours in a constant temperature dryer. Bleedability was evaluated according to the following criteria.

AA: No bleed of modifier BB: There is a slight bleed of modifier

CC: There is a bleed of the modifier.

[0087] <Formability (spinnability)>

The number of yarn breaks during 10 minutes during melt spinning was visually observed. Formability (spinnability) was evaluated according to the following criteria.

○: No thread breakage

△: Thread breakage (once Zio minutes or less)

X: Thread breakage (twice Z10 minutes or more).

[Example 1]

Using polylactic acid [manufactured by Mitsui Chemicals Co., Ltd., trade name: LACEA H-400] as biodegradable polyester, at 200-220 ° C with a twin screw extruder, Daifati 101 as a modifier The mixture was blended at a weight ratio of 85Z15 while charging [Hachikagaku Kogyo Co., Ltd.] to obtain pellets. The obtained pellets were dried at 60-70 ° C. The dried pellets were melt-spun by the spunbond method, and the web was heated and pressurized with an embossing roll to obtain a nonwoven fabric having a basis weight of 20 gZm2. The obtained nonwoven fabric was evaluated by measuring mechanical strength, bending resistance, and the like. The results are shown in Table 1.

[Example 2]

Using polylactic acid [manufactured by Mitsui Chemicals Co., Ltd., trade name: LACEA H-400] as biodegradable polyester, at 200-220 ° C with a twin screw extruder, Daifati 101 as a modifier The mixture was blended at a weight ratio of 75Z25 while charging [made by Hachikagaku Kogyo Co., Ltd.] to obtain pellets. The obtained pellets were dried at 60-70 ° C. The dried pellets were melt-spun by the spunbond method, and the web was heated and pressurized with an embossing roll to obtain a nonwoven fabric having a basis weight of 20 gZm2. The obtained nonwoven fabric was evaluated by measuring mechanical strength, bending resistance, and the like. The results are shown in Table 1.

[Comparative Example 1]

In Example 1, the weight per unit area was 20 gZm in the same manner as in Example 1 except that only the polylactic acid [manufactured by Mitsui Chemicals, Inc., trade name: LACE A H-400] was used without adding a modifier. ^Two nonwoven fabrics were obtained. The obtained nonwoven fabric was evaluated by measuring mechanical strength and the like. Results in Table 1 Shown in

[0091] [Comparative Example 2]

Polylactic acid resin (Mitsui Chemicals Co., Ltd., trade name: LACEA H-400) and aliphatic polyester (Showa High Polymer Co., Ltd., trade name: Bionore # 1020) were blended at a weight ratio of 85Z15 and spanned. Melt spinning was performed by a bond method, and the web was heated and pressurized with an embossing roll to obtain a nonwoven fabric having a basis weight of 20 g / m ² . The obtained nonwoven fabric was measured and evaluated by measuring the mechanical strength and the like. The results are shown in Table 1.

[Comparative Example 3]

A nonwoven fabric having a basis weight of 20 gZm ² was obtained in the same manner as in Example 1 except that the modifier was ATBC (acetyltributyl citrate) in Example 1. The obtained nonwoven fabric was evaluated by measuring mechanical strength and the like. The results are shown in Table 1.

[0093] [Comparative Example 4]

Using polylactic acid [manufactured by Mitsui Chemicals Co., Ltd., trade name: LACEA H-400] as biodegradable polyester, at 200-220 ° C with a twin screw extruder, Daifati 101 as a modifier The mixture was blended at a weight ratio of 65Z35 while charging [Hachikagaku Kogyo Co., Ltd.] to obtain pellets. The obtained pellets were dried at 60-70 ° C. The dried pellets were melt-spun by the spunbond method, and the web was heated and pressurized with an embossing roll to obtain a nonwoven fabric having a basis weight of 20 gZm2. The obtained nonwoven fabric was evaluated by measuring mechanical strength, bending resistance, and the like. The results are shown in Table 1.

[Example 3]

Using polylactic acid [manufactured by Mitsui Chemicals Co., Ltd., trade name: LACEA H-400] as biodegradable polyester, at 200-220 ° C with a twin screw extruder, Daifati 101 as a modifier The mixture was blended at a weight ratio of 90Z10 while charging [Hachikagaku Kogyo Co., Ltd.]. The obtained pellets were dried at 60-70 ° C. The dried pellets were melt-spun by the spunbond method, and the web was heated and pressurized with an embossing roll to obtain a nonwoven fabric having a basis weight of 20 gZm2. The obtained nonwoven fabric was evaluated by measuring mechanical strength, bending resistance, and the like. The results are shown in Table 1.

[Preparation Example 1] Decomposition accelerator (aspartic acid lactic acid copolymer, PALS) A glass-lined 4 m ³ reactor was charged with 130 kg of aspartic acid and 500 kg of 90% L-lactic acid aqueous solution, and reacted at 180 ° C for 25 hours while distilling off the reaction water under a nitrogen stream. The product was taken out from the outlet at the bottom of the reaction kettle and cooled and solidified, and the resulting solid was pulverized to obtain a powdery polymer (aspartic acid-lactic acid copolymer, PALS). The weight average molecular weight (Mw) was 9000.

[Example 4]

Using polylactic acid [manufactured by Mitsui Chemicals Co., Ltd., trade name: LACEA H-400] as biodegradable polyester, at 200-220 ° C with a twin screw extruder, Daifati 101 as a modifier Yachikagaku Kogyo Co., Ltd.] and aspartic acid lactic acid copolymer (PALS) obtained in Preparation Example 1 as a decomposition accelerator were charged and blended at a weight ratio of 80Z15Z5 to obtain pellets. The obtained pellets were dried at 60-70 ° C. Was melt spun by spunbond method using drying was performed pellets, basis weight and heat and pressure treatment a web with an embossing roll to obtain a 20 g Zm ² of the nonwoven fabric. The obtained nonwoven fabric was evaluated by measuring mechanical strength, bending resistance, and the like. The results are shown in Table 1.

[0097] [Table 1]

Modified material b1: Daifatsu-101 [Daihachi Chemical Industry Co., Ltd.] Modified material b2: Bionore # 1020 [Showa Polymer Co., Ltd.] Modified material b3: ATBC (Acetyl "Butyl Chenic Acid) Decomposition accelerator d 1: Us / Laginate-lactic acid copolymer (PALS)

[0098] As shown in Table 1 above, from comparison between Examples 1 to 4 and Comparative Examples 1 to 4, Examples 1 to 4 in which specific modifiers were blended at specific ratios were mechanical strength and rigidity. It was found that the softness balance and heat shrink resistance were excellent.

[0099] [Reference Example]

The nonwoven fabrics obtained in Examples 1 and 4 and Comparative Example 1 were placed in 35 ° C. distilled water, lap samples were taken for 1 week and 2 weeks, and the weight average molecular weight (Mw) was measured. The molecular weight retention was calculated by the following method.

[0100] Molecular weight retention = (Mw of lap sample) / (Mw before test) X 100 (%)

Mw was determined by comparison with a polystyrene standard sample using gel permeation chromatography (GPC) at a column temperature of 40 ° C. and a chloroform solvent. The results are shown in Table 2.

[0101] [Table 2] Reference Example 1 Reference Example 2 Reference Example 3 Example 4 Example 4 Example 1 Nonwoven Fabric Type

Nonwoven Nonwoven Nonwoven

0 series 100 100 100 Molecular weight retention (%) 7 series 82 98 99

14th Eye 74 95 97

Claims

Claims [1] Biodegradable polyester (A) 70 to 99 parts by weight and modifier (B) 30 to 1 part by weight (provided that the sum of (A) and (B) is 100 parts by weight) A biodegradable polyester fiber comprising the biodegradable polyester composition (C), wherein the modifying material (B) is an ester compound represented by the following general formula (1).

[Chemical 1]

R ¹ OOC― (CH ₂ ) _m — COOR ² … ₍₁₎

(In the formula, R ¹ and R ² are different from each other, and each represents a group represented by the following general formula (2), and m represents an integer of 0 to 8.)

[Chemical 2] One (R ³ 0) _n R ⁴ _... ₍₂₎

(Wherein R ³ represents an alkylene group having 1 to 6 carbon atoms, R ⁴ represents a linear or branched alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or 7 to 15 carbon atoms. And an arylaryl group having 7 to 15 carbon atoms, and n represents an integer of 0 to 6.)

[2] The biodegradable polyester fiber according to claim 1, wherein the thermal shrinkage at 130 ° C is 10% or less.

[3] The biodegradable polyester fiber according to [1], wherein the biodegradable polyester (A) is a lactic acid resin.

[4] The biodegradable polyester fiber according to [1], wherein the biodegradable polyester (A) is polylactic acid.

[5] The biodegradable polyester composition (C) contains 100 parts by weight of the total amount of the biodegradable polyester (A) and the modified material (B). The biodegradable polyester fiber according to claim 1, further comprising 20 parts by weight.

[6] A biodegradable polyester nonwoven fabric characterized by comprising a biodegradable polyester fiber cable according to any one of claims 1 to 5.

[7] Longitudinal (MD) bending resistance QilS L1096 Method A as described in 8.1. 7. The biodegradable polyester nonwoven fabric according to claim 6, wherein the total value of the conformity] and the transverse (CD) bending resistance [according to the law] is 100 mm or less.

[8] The longitudinal direction (MD) bending resistance is 60mn! The biodegradable polyester nonwoven fabric according to claim 7, wherein the biodegradable polyester nonwoven fabric is Omm.

[9] Bending softness in the transverse direction (CD) 0mn! The biodegradable polyester nonwoven fabric according to claim 7, wherein the biodegradable polyester nonwoven fabric is Omm.

[10] A sanitary article comprising the biodegradable polyester nonwoven fabric according to any one of claims 6 to 9.

11. The sanitary product according to claim 10, wherein the sanitary product is at least one selected from a sanitary napkin, a panty liner, a disposable paper diaper, and a sanitary tampon applicator.