JPH09158021A - Nonwoven fabric made of lactic acid type copolyester - Google Patents

Abstract

(57) [Summary] [PROBLEMS] The problem to be solved by the present invention is to have biodegradability, excellent flexibility, mechanical strength, heat resistance, moldability, dimensional stability, and storage stability. Another object of the present invention is to provide a nonwoven fabric made of lactic acid-based copolyester. A lactic acid component (A), a dicarboxylic acid component (B), and a diol component (C) are contained as structural units.
A nonwoven fabric composed of a lactic acid-based copolyester having a melting point of 110 ° C. to 190 ° C., and a lactic acid component (A), a dicarboxylic acid component (B), a diol component (C), and a high molecular weight agent (D) as structural units. A nonwoven fabric made of lactic acid-based copolyester having a melting point of 110 ° C to 190 ° C.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention uses a lactic acid-based copolyester containing a lactic acid component, a dicarboxylic acid component and a diol component as structural units, has biodegradability, has a low combustion calorific value, and is excellent. The present invention relates to a non-woven fabric having mechanical strength, heat resistance, moldability, dimensional stability, and storage stability.

The non-woven fabric made of the lactic acid-based copolyester of the present invention is used for heat retention / water retention / curing / bird protection sheets, mulch film, sheet for planting roots, agricultural materials such as fertilizer bags, and civil engineering such as vegetation sheets. It is useful in various fields such as materials, sanitary materials such as disposable diapers and sanitary items, disposable hand towels, wiping cloths, base cloths of pap materials, filters for air purifiers and the like.

Further, the nonwoven fabric of the present invention, for example, when left in a natural environment, is hydrolyzed, decomposed by microorganisms and the like, and even when incinerated, its calorific value of combustion is low, so that it is possible to preserve the natural environment. It is useful from a viewpoint.

[0004]

2. Description of the Related Art In recent years, since plastics are excellent in properties such as durability, soft texture, and heat-sealing property, they have been widely used in various fields utilizing these properties.
However, since these wastes are hardly decomposed in the natural environment, they are accumulated in the natural world and cause problems such as pollution of rivers, oceans, and soil, which is a major social problem.

As a means for suppressing this environmental pollution, it has been desired to develop a biodegradable plastic which is decomposed by microorganisms in water or soil and incorporated into the natural material circulation system, and which does not pollute the environment. Copolymerized polyesters of 3-hydroxybutyrate and 3-hydroxyvalerate produced, polylactic acid, polycaprolactone, aliphatic polyesters composed of dicarboxylic acids and diols, blends of starch of natural polymers and modified polyvinyl alcohol, etc. Are known.

Regarding fibers and non-woven fabrics made of these polymers and blends, JP-A-6-207323 is used.
No. 6,207,324, No. 6-248511, No. 6-248516, and the like.

However, the copolyester of 3-hydroxybutyrate and 3-hydroxyvalerate produced by microorganisms is excellent in biodegradability, but the thermal decomposition temperature is close to the melting point, so that the molding process is difficult and the molding shrinkage is large. Moreover, the obtained nonwoven fabric is brittle and has a strong odor, which is a problem in practical use.

Polylactic acid has a high melting point and excellent rigidity, but on the other hand, it is inferior in flexibility, and since a large amount of lactide remains in it, it is inferior in thermal stability and has a molecular weight due to heat during molding. As a result, lactide or the like adheres to the molding processing device or the molded processing product to cause troubles in the molding processing device, and there are not enough products to be obtained. This is because lactide becomes an organic acid due to moisture in the atmosphere and cleaves the polymer.

Polycaprolactone is excellent in flexibility,
It has a low melting point of about 60 ° C and is inferior in heat resistance. An aliphatic polyester composed of an aliphatic dicarboxylic acid and a diol also has good flexibility, but has a low melting point of 90 ° C to 110 ° C,
There are practical and practical restrictions. A blend of a natural polymer starch and a modified polyvinyl alcohol has relatively good biodegradability and moldability, but is inferior in strength, water resistance and storage stability, and is considerably restricted in use.

As mentioned above, these biodegradable polymers are
The non-woven fabric made from consists of its physical properties, moldability, heat stability,
Since storage stability and the like are still insufficient, there are considerable restrictions in terms of use, and there has been a demand for a nonwoven fabric made of a biodegradable polymer that can change its physical properties in a wide range depending on the use.

[0011]

Therefore, the problem to be solved by the present invention is to have biodegradability and excellent flexibility,
A non-woven fabric made of lactic acid-based copolyester having mechanical strength, heat resistance, moldability, dimensional stability, and storage stability.

[0012]

[Means for Solving the Problems] The present inventors have found that a lactic acid component and a copolymerization component with the lactic acid component, copolymerization conditions, spinning conditions,
As a result of examining the conditions of the non-woven fabric, while maintaining good biodegradability, it has a good texture, sufficient flexibility, heat resistance, mechanical strength, and is stable without deterioration of physical properties during storage,
Moreover, the present invention has been completed by obtaining a nonwoven fabric made of lactic acid-based copolyester which is excellent in moldability.

That is, the present invention is a non-woven fabric composed of a lactic acid-based copolyester having a melting point of 110 ° C. to 190 ° C., which contains a lactic acid component (A), a dicarboxylic acid component (B) and a diol component (C) as structural units. Also, the lactic acid component (A), the dicarboxylic acid component (B), the diol component (C), and the high molecular weight agent (D) are contained as structural units, and the melting point is 110 ° C. to 19 ° C.
A non-woven fabric made of lactic acid-based copolyester at 0 ° C.

The nonwoven fabric containing the high molecular weight agent (D) in the lactic acid-based copolyester of the present invention is, specifically, the high molecular weight agent (D) is a polycarboxylic acid, a metal complex, an epoxy compound or an isocyanate. , One or more compounds selected from the group consisting of acid phosphates and chelating agents.

The present invention also relates to the dicarboxylic acid component (B).
And the diol component (C) are, in particular, an aliphatic dicarboxylic acid component and an aliphatic diol component, and a nonwoven fabric composed of a lactic acid-based copolyester, and a dicarboxylic acid component (B) of the lactic acid-based copolyester used. And the diol component (C) is a nonwoven fabric which is a lactic acid-based copolyester having a branched chain, and the dicarboxylic acid component (B) and the diol component (C) of the lactic acid-based copolyester used are aliphatic dicarboxylic acids. It is a component and an aliphatic diol component, and includes a nonwoven fabric composed of a lactic acid-based copolyester having a branched chain.

Further, in the present invention, after melt-spinning a lactic acid-based copolyester, the obtained yarn is further processed at 60 ° C to 150 ° C.
A nonwoven fabric made of lactic acid-based copolyester yarn heat-treated in a temperature range of ℃ or a yarn made of lactic acid-based copolyester is used as a binder, and has a melting point 20 to 50 ° C. higher than that of the lactic acid-based copolyester used for the binder A non-woven fabric made of a lactic acid-based copolyester obtained by mixing the yarns made of the lactic acid-based copolyester and bonding the yarns together,

The core portion is composed of a lactic acid-based copolyester, and the sheath portion is composed of a core-sheath type composite short yarn composed of a lactic acid-based copolyester having a melting point lower than that of the lactic acid-based copolyester, and the constituent threads are Is partially heat-bonded, and also includes a nonwoven fabric made of lactic acid-based copolyester.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The lactic acid-based copolyester used in the present invention contains a lactic acid component, a dicarboxylic acid component and a diol component as structural units.

As a method for producing the same, a method of copolymerizing or transesterifying a polyester composed of a dicarboxylic acid component and a diol component and lactide, which is a dehydrated cyclic dimer of lactic acid, in the presence of a ring-opening polymerization catalyst, , Lactic acid component,
A method of dehydrating and diglycolizing a dicarboxylic acid component and a diol component in the presence of a catalyst,

Alternatively, polylactic acid obtained by using lactide as a raw material or obtained by condensing lactic acid in the presence or absence of a solvent and a polyester composed of a dicarboxylic acid component and a diol component in the presence of an ester exchange catalyst. Examples thereof include a method of transesterification.

The addition timing of the high molecular weight agent in the method for producing a lactic acid-based copolyester containing the high molecular weight agent used in the present invention varies depending on the kind of the high molecular weight agent, but it is a polyvalent carboxylic acid. , The metal complex, the epoxy compound, the high molecular weight agent (I) such as isocyanate may be added in any step such as a pre-process, a middle process, a post-process of the polymerization, a devolatilization process after the polymerization, an extrusion process and a processing process. Also, high molecular weight agents (II) such as acid phosphates and chelating agents are
It is preferably added in the final stage of the polymerization step, the devolatilization step, the extrusion step, the processing step and the like.

More specifically, in particular, a method in which a polyester composed of a dicarboxylic acid component and a diol component is reacted with a high molecular weight agent (I), and then lactide is copolymerized in the presence of a ring-opening polymerization catalyst, Further, the lactic acid-based copolyester obtained by copolymerizing a polyester composed of a dicarboxylic acid component and a diol component and lactide in the presence of a ring-opening polymerization catalyst is added with a high molecular weight agent (I) and / or (II). How to react,

A method of dehydrating the polylactic acid component, the dicarboxylic acid component, the diol component and the high molecular weight agent (I) in the presence of a catalyst, polycondensation by deglycollation or a transesterification reaction,
The lactic acid component, the dicarboxylic acid component, and the diol component are dehydrated in the presence of a catalyst, polycondensation by deglycollation, or a copolymer obtained by a transesterification reaction, and a high molecular weight agent (I) and / or
Alternatively, a method of reacting (II) may be mentioned.

Further, polylactic acid obtained from lactide as a raw material, or polylactic acid obtained by polycondensation of lactic acid in the presence or absence of a solvent, and polyester containing a dicarboxylic acid component and a diol component A method of transesterification in the presence of a molecular weight agent (I) and / or (II) and an ester exchange catalyst, polylactic acid obtained from lactide as a raw material, or lactic acid is polycondensed in the presence or absence of a solvent. After transesterification of the polylactic acid thus obtained with a polyester composed of a dicarboxylic acid component and a diol component in the coexistence of an ester exchange catalyst, the obtained lactic acid-based copolyester is provided with a high molecular weight agent (I) and / or ( II) can be used.

In particular, as a method for reducing the residual volatile matter such as lactide in the lactic acid-based copolyester, it is preferable to add a high molecular weight agent and after the reaction, remove the volatile matter under reduced pressure. When the high molecular weight agent (II) is used, a great effect can be obtained in reducing the residual lactide.

In the production of the lactic acid-based copolyester used in the present invention, a hydroxycarboxylic acid component other than lactic acid, a polyhydric alcohol component, a cyclic ester other than lactide, etc. are used as long as the biodegradability and physical properties thereof are not impaired. May be included. The timing of its addition is not particularly limited, but it is preferable when producing a polyester composed of a dicarboxylic acid component and a diol component, or when producing a lactic acid-based copolyester by copolymerizing the polyester with lactide.

Further, in order to reduce the viscosity during the polymerization, enhance the stirring efficiency, and obtain good quality, the reaction components and an inert solvent can be used in the production process. Examples of solvents that can be used are benzene, toluene, ethylbenzene,
Examples include xylene, cyclohexanone, diphenyl ether and the like. The addition amount varies depending on the production method, production conditions, type of reaction components, composition, etc., but is usually 50% by weight or less, preferably 30% by weight or less based on the lactic acid-based copolyester.

Examples of the ring-opening polymerization catalyst and transesterification catalyst used in the production of the lactic acid-based copolyester of the present invention include metals such as tin, zinc, lead, titanium, bismuth, zirconium and germanium, and compounds thereof. Among the metal compounds, metal organic compounds, carbonates and halides are particularly preferable.

Specifically, tin octoate, tin chloride, zinc chloride, zinc acetate, lead oxide, lead carbonate, titanium chloride, diacetoacetoxyoxytitanium, tetraethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium, germanium oxide, Zirconium oxide and the like are suitable. The amount added is 0.001% by weight to the total amount of the reaction components.
1.0% by weight is preferred. Further, the addition amount thereof is preferably 0.002% by weight to 0.5% by weight in view of reaction rate, coloring and the like.

As the catalyst used in the production of the polyester composed of the dicarboxylic acid component and the diol component, metals such as tin, zinc, titanium, zirconium and the compounds thereof are preferable. Specifically, tin octoate, chloride Examples thereof include tin, zinc chloride, zinc acetate, diacetoacetoxyoxytitanium, tetraethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium and zirconium oxide.

These are 0.00 relative to polyester.
1% by weight to 0.5% by weight, preferably 0.002% by weight
It is preferred to add ~ 0.1% by weight from the beginning of the esterification or just before the deglycolization reaction.

Further, the lactic acid-based copolyester used in the present invention includes known and conventional antioxidants, heat stabilizers,
UV absorbers, lubricants, antistatic agents, flame retardants, waxes, colorants, crystallization accelerators, etc. are added in the pre-process, middle process, post-process, post-polymerization devolatilization process, extrusion process, etc. May be. The amount added is usually 0.001% by weight to
1% by weight is preferred.

Specifically, as the antioxidant, 2,6
-Di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, distearyl 3,3'-thiodipropionate, dilauryl 3,3'-thio Dipropionate, etc.

As the heat stabilizer, triphenyl phosphite, trilauryl phosphite, trisnonyl phenyl phosphite, etc., and as the ultraviolet absorber, pt
-Butylphenyl salicylate, 2-hydroxy-4-
Methoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2,4,5-trihydroxybutyrophenone,

As the lubricant, calcium stearate,
Zinc stearate, barium stearate, sodium palmitate, etc. are used as antistatic agents such as N, N-bis (hydridoxyethyl) alkylamines, alkylamines, alkylallyl sulfonates and alkyl sulfonates. Examples of the flammable agent include hexabromocyclododecane, tris- (2,3-dichloropropyl) phosphate, pentabromophenyl allyl ether and the like.

The reaction temperature at the time of producing the lactic acid-based copolyester used in the present invention varies depending on the type, amount and combination of the copolymer components such as polyester and cyclic ester, but is usually 125 ° C to 270 ° C, preferably Is 14
The temperature is 0 ° C to 250 ° C, more preferably 150 ° C to 230 ° C.

In order to suppress the decomposition and coloration of the obtained lactic acid-based copolyester, the reaction atmosphere is a dry state without water, for example, under a nitrogen, argon or gas atmosphere.
Alternatively, the reaction is performed in the bubbling state. It is necessary to remove water from the raw materials used and dry them.

Unreacted components in the obtained lactic acid-based copolyester, especially volatile components such as lactide and solvent, are removed by a devolatilization apparatus such as a devolatilization tank, a film evaporator, and a vented extruder attached after the polymerization step. Remove or dissolve with a solvent such as alcohol, ketone, hydrocarbon,
After immersion or dispersion, it is extracted and removed. By such a method, the residual lactide in the lactic acid-based copolyester can be reduced to 1% by weight or less, and if necessary, 0.5% by weight or less. These treatments are preferable from the standpoint of molding processing or enhancing the heat resistance and storage stability of the nonwoven fabric.

The component composition of the lactic acid-based copolyester used in the present invention will be described below in order. Regarding the ratio of the lactic acid component, the dicarboxylic acid component and the diol component of the present invention, in order to maintain good heat resistance, the ratio of the lactic acid component and the total component of the dicarboxylic acid component and the diol component is 99/1 to 40/60 is preferred.

In the present invention, in order to obtain a lactic acid-based copolyester having excellent heat resistance, it is preferable that the lactic acid component has a high optical activity. Specifically, as the lactic acid component of the structural component of the lactic acid-based copolyester of the present invention, it is preferable that L-form or D-form is contained in 70% by weight or more in the total lactic acid. In order to obtain higher heat resistance, it is preferable that the L-form or D-form is 80% by weight or more. Also,
With respect to lactide, it is preferable that L-form or D-form is contained in an amount of 70% by weight or more in the total lactide. In order to obtain higher heat resistance, it is preferable that the L-form or D-form is 80% by weight or more.

In particular, since L-lactic acid is commercially less expensive and can be obtained in high purity by fermentation synthesis, the lactic acid component of the structural component of the lactic acid-based copolyester is
It is preferable to use L-lactic acid and L-lactide as the lactide.

As the high molecular weight agent, lactic acid component,
0.0 of the total of the dicarboxylic acid component and the diol component
01% to 5% by weight, more preferably 0.01% by weight
It is preferably about 2% by weight. When it exceeds 5% by weight, the lactic acid-based copolyester is not preferable because it causes gelation, coloring, and a decrease in viscosity.
When it is 0.001% by weight, the effect of increasing the molecular weight of the lactic acid-based copolyester is small, and sufficient effects on flexibility, mechanical strength, moldability, etc. are not recognized.

The lactic acid-based copolyester used in the nonwoven fabric of the present invention preferably has a molecular weight above a certain level, specifically, the weight average molecular weight is 20,000 to 400,000, more preferably 30,000 to 200,000. Is. If it is less than 20,000, the strength of the nonwoven fabric is insufficient, and if it exceeds 400,000, there is a problem in molding and production efficiency, which is not preferable.

The dicarboxylic acid component in the lactic acid-based copolyester is not particularly limited, but specifically, succinic acid, methylsuccinic acid, 2-methyladipic acid, methylglutaric acid, adipic acid, azelaic acid, sebacic acid,
Brassylic acid, dodecanedicarboxylic acid, cyclohexanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid,
Examples thereof include naphthalenedicarboxylic acid, dimer acid, maleic acid (anhydrous), and fumaric acid.

The diol component in the lactic acid-based copolyester is not particularly limited as long as it is a diol. Specifically, ethylene glycol, propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,4-pentanediol, 1,5-pentanediol, 2,4-
Pentanediol, hexanediol, octanediol,

Examples include neopentyl glycol, cyclohexanedimethanol, xylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, polytetramethylene glycol and hydrogenated bisphenol A.

In particular, when an aliphatic dicarboxylic acid component or an aliphatic diol component is used as the dicarboxylic acid component or diol component in the lactic acid-based copolyester, it is preferable because it is excellent in biodegradability. Furthermore, those having a branched chain as the dicarboxylic acid component and the diol component are particularly preferable because the fibers and nonwoven fabrics obtained therefrom have excellent dyeability.

Furthermore, when polyalkylene glycol is used as the diol component, a lactic acid-based copolyester having excellent flexibility can be obtained. Specific examples thereof include polyethylene glycol having a molecular weight of 200 to 20,000, polypropylene glycol, polyethylene glycol / polypropylene glycol copolymer, polybutylene glycol, polytetramethylene glycol, or a mixture thereof. Above all, polypropylene glycol having a branched chain is preferred in order to enhance the dyeability in addition to the flexibility.

Examples of the high molecular weight agent include polyvalent carboxylic acids, metal complexes, epoxy compounds, isocyanates, acidic phosphoric acid esters, chelating agents and the like, and these can be used alone or in combination.

As the polycarboxylic acid, (anhydrous) phthalic acid, hexahydrophthalic acid, (anhydrous) maleic acid, (anhydrous) trimellitic acid, trimethyladipic acid, (anhydrous)
Pyromellitic acid, (anhydrous) 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, Epiclon 4400 manufactured by Dainippon Ink and Chemicals, Inc. and the like. A mixture may be mentioned. In particular, carboxylic acids having three or more functional groups are effective in increasing the molecular weight.

Examples of the metal complex include lithium formate, sodium methoxide, potassium propionate, magnesium ethoxide, calcium propionate, manganese acetylacetonate, cobalt acetylacetonate, zinc acetylacetonate, cobalt acetylacetonate, and iron acetylacetonate. , Aluminum acetylacetonate, aluminum isopropoxide, and tetrabutoxytitanium are preferable, and divalent or higher-valent metal complexes are more preferable.

As the epoxy compound, bisphenol A type diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, terephthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, ο-
Diglycidyl phthalate, 3,4-epoxycyclohexylmethyl-3,4 epoxycyclohexanecarboxylate, bis (3,4 epoxycyclohexyl)
Adipate, tetradecane-1,14-dicarboxylic acid glycidyl ester and the like can be used.

As the isocyanate, hexamethylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate,
1,5-naphthylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, diisocyanate-modified polyether, diisocyanate-modified polyester, polyhydric alcohol-modified bifunctional isocyanate, polyisocyanate-modified polyether, And polyesters modified with polyvalent isocyanates and mixtures thereof.

Examples of the acidic phosphoric acid ester include acidic phosphoric acid ester, phosphonic acid ester, alkylphosphonic acid and the like. Specifically, as the acidic phosphate ester, monomethyl phosphate, dimethyl phosphate, monoethyl phosphate, diethyl phosphate, monopropyl phosphate, dipropyl phosphate, monoisopropyl phosphate, diisopropyl phosphate, monobutyl phosphate, Dibutyl phosphate, monopentyl phosphate, dipentyl phosphate, monohexyl phosphate, dihexyl phosphate, monooctyl phosphate,

Dioctyl phosphate, monoethylhexyl phosphate, diethylhexyl phosphate, monodecyl phosphate, didecyl phosphate, monoisodecyl phosphate, diisodecyl phosphate, monoundecyl phosphate, diundecyl phosphate, monododecyl phosphate, didodecyl phosphate, Monotetradecyl phosphate, ditetradecyl phosphate, monohexadecyl phosphate, dihexadecyl phosphate, monooctadecyl phosphate, dioctadecyl phosphate, monophenyl phosphate, diphenyl phosphate, monobenzyl phosphate, dibenzyl phosphate, etc.,

Examples of the phosphonate ester include monomethyl phosphonate, monoethyl phosphonate, monopropyl phosphonate, monoisopropyl phosphonate, monobutyl phosphonate, monopentyl phosphonate, monohexyl phosphonate, monooctyl phosphonate, monoethylhexyl phosphonate, Monodecyl phosphonate, monoisodecyl phosphonate, monoundecyl phosphonate, monododecyl phosphonate, monotetradecyl phosphonate, monohexadecyl phosphonate, monooctadecyl phosphonate, monophenyl phosphonate, monobenzyl phosphonate, etc.,

As the alkylphosphonic acid, monomethylphosphonic acid, dimethylphosphonic acid, monoethylphosphonic acid, diethylphosphonic acid, monopropylphosphonic acid, dipropylphosphonic acid, monoisopropylphosphonic acid, diisopropylphosphonic acid, monobutylphosphonic acid, Dibutylphosphonic acid, monopentylphosphonic acid, dipentylphosphonic acid, monohexylphosphonic acid, dihexylphosphonic acid, isooctylphosphonic acid, dioctylphosphonic acid, monoethylhexylphosphonic acid, diethylhexylphosphonic acid, monodecylphosphonic acid, didecylphosphonic acid ,

Monoisodecylphosphonic acid, diisodecylphosphonic acid, monoundecylphosphonic acid, diundecylphosphonic acid, monododecylphosphonic acid, didodecylphosphonic acid, monotetradecylphosphonic acid, ditetradecylphosphonic acid, monohexadecylphosphonic acid Acid, dihexadecylphosphonic acid, monooctadecylphosphonic acid, dioctadecylphosphonic acid, monophenylphosphonic acid,
Mention may be made of diphenylphosphonic acid, monobenzylphosphonic acid, dibenzylphosphonic acid, etc., and mixtures thereof.

As the chelating agent usable in the present invention,
There are organic chelating agents and inorganic chelating agents. Organic chelating agents have low hygroscopicity and are excellent in thermal stability. The organic chelate that can be used is not particularly limited, but amino acids, phenols, hydroxycarboxylic acids,
Diketones, amines, oximes, phenanthrolines, pyridine compounds, dithio compounds, N as a coordination atom
Examples thereof include phenol, N-containing carboxylic acid as a coordinating atom, diazo compound, thiols and porphyrins.

They form a complex with the metal ion of the catalyst contained in the lactic acid-based copolyester to lose the catalytic activity. Specifically, glycine, leucine, alanine, serine, α-aminobutyric acid, acetylaminoacetic acid, glycylglycine, glutamic acid, etc. as amino acids, and alizarin, t-butylcatechol, 4-isopropyltropolone, chromotrope as phenols. Acid, tyron, oxine, propyl gallate, etc.,

Hydroxycarboxylic acids include tartaric acid, oxalic acid, citric acid, monooctyl citrate, dibenzoyl-
D-tartaric acid, diparatoluoyl-D-tartaric acid, etc., and diketones such as acetylacetone, hexafluoroacetylacetone, benzoylacetone, thenoyltrifluoroacetone, trifluoroacetylacetone, etc.

As the amines, ethylenediamine, diethylenetriamine, 1,2,3-triaminopropane,
Thiodiethylamine, triethylenetetramine, triethanolamine, tetraethylenepentamine, pentaethylenehexamine and the like, oximes such as dimethylglyoxime, α, α-furyldioxime and salicylaldoxime, and phenanthrolines such as neocuproine,

Pyridine compounds such as 1,10-phenanthroline include 2,2-bipyridine and 2,2 ', 2 ".
-Terpyridyl and other dithio compounds include xanthogenic acid, diethyldithiocarbamic acid, toluene-3,4
-Examples of the phenol containing a coordination atom N such as dithiol include o-aminophenol, oxine, nitroso R salt,
2-nitroso-5-dimethylaminophenol, 1-nitroso-2-naphthol, 8-selenoquinoline, etc.

As the carboxylic acid containing a coordinating atom N, quinaldic acid, nitrilotriacetic acid, ethylenediaminediacetic acid, hydroxyethylethylenediaminetriacetic acid, ethylenediaminetetraacetic acid, trans-cyclohexanediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, Aniline diacetic acid, 2-sulfoaniline diacetic acid, 3-sulfoaniline diacetic acid,

4-sulfoanilinediacetic acid, 2-aminobenzoic acid-N, N-diacetic acid, 3-aminobenzoic acid-N, N
-Diacetic acid, 4-aminobenzoic acid-N, N-diacetic acid, methylaminediacetic acid, β-alanine-N, N-diacetic acid, β-
Aminoethylsulfonic acid-N, N-diacetic acid, β-aminoethylphosphonic acid-N, N-diacetic acid, etc.,

As diazo compounds, diphenylcarbazone, magneson, dithizone, eriochrome black T,
Thiols such as 4- (2-thiazolylazo) resorcinol and 1- (2-pyridylazo) -2-naphthol, thiooxine, thionalide, 1,1,1-trifluoro-4- (2-thienyl) -4-mercapto -3-buten-2-one, 3-mercapto-p-cresol, etc.,

Examples of the porphyrins include tetraphenylporphine, tetrakis (4-N-methylpyridyl) porphine and the like, and other examples include cuperon, murexide, polyethyleneimine, polymethylacryloylacetone, polyacrylic acid and mixtures thereof. .

The inorganic chelating agent has a high hygroscopic property, and if it absorbs moisture, it loses its effect. Therefore, it must be handled with care. Specific examples include phosphoric acids such as phosphoric acid, phosphorous acid, pyrophosphoric acid, and polyphosphoric acid.

The addition of such a high molecular weight agent is effective not only for increasing the molecular weight of the lactic acid-based copolyester, but also for suppressing the decrease in the molecular weight due to heat. The molecular weight and thermal stability can be improved depending on the type, combination, addition amount and the like.

In particular, the high molecular weight agent such as polyvalent carboxylic acid, metal complex, epoxy compound and isocyanate is used for the polymerization step of lactic acid type copolyester, the devolatilization step, the extrusion step,
It is added to the processing step, etc., and is effective in increasing the molecular weight by reacting with lactic acid-based copolyester, and acidic phosphates, chelating agents, etc. are added after the polymerization,
It is particularly effective in suppressing the thermal decomposition during reaction by reacting. Among the high molecular weight agents, those using an aliphatic compound have an advantage of excellent biodegradability.

The flexibility, crystallinity, heat resistance and the like of the non-woven fabric obtained by using a hydroxycarboxylic acid component other than lactic acid as the copolymerization component can be adjusted. Sex, etc. will decrease.

The hydroxycarboxylic acid component is not particularly limited, but specifically, glycolic acid, dimethyl glycolic acid, 3-hydroxypropionic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2 -Hydroxyvaleric acid, 3-hydroxyvaleric acid, 4
-Hydroxyvaleric acid, 5-hydroxyvaleric acid, 2-hydroxycaproic acid, 3-hydroxycaproic acid, 4-hydroxycaproic acid, 5-hydroxycaproic acid, 5-
Hydroxymethylcaproic acid, 6-hydroxycaproic acid, 6-hydroxymethylcaproic acid and the like and mixtures thereof can be used.

Further, a polyhydric alcohol such as trimethylolpropane or pentaerythritol may be contained as a constituent component as a melt viscosity adjusting agent in the polymerization step of the lactic acid type copolyester, the molding step and the like.

As the cyclic ester of the copolymerization component,
Intermolecular cyclic dimer of hydroxycarboxylic acid such as glycolide, ε-caprolactone, γ-valerolactone, γ-
Intramolecular cyclic cyclic esters of hydroxycarboxylic acids such as undecalactone and β-methyl-δ-valerolactone can be used alone or in combination. Copolymerization of these cyclic esters can increase flexibility and lower the melting point.

The process of forming the lactic acid-based copolyester of the present invention into yarn and fibers is described below. The staple fiber composed of the lactic acid-based copolyester used in the present invention can be produced by melt spinning the lactic acid-based copolyester, stretching it, mechanically crimping it, and cutting it.

The melt spinning temperature is 170 to 300 ° C., preferably 170 to 250 ° C., from the melting point of the lactic acid-based copolyester used in the present invention and the thermal decomposition initiation temperature. If the spinning temperature is less than 170 ° C, melt extrusion is difficult, and if it exceeds 300 ° C, decomposition is remarkable, and it becomes difficult to obtain high-strength staple fibers having excellent crimping properties.

The melt-spun yarn is rapidly cooled below the crystallization temperature. In this case, the melting point of the lactic acid-based copolyester is generally low, so that the crystallization temperature is about 60 to 130.
Since the temperature is in the range of ℃, unless it is sufficiently cooled so as to promote a certain oriented crystallization in the draft process from the nozzle to the take-up roller, the obtained yarn will have poor mechanical strength and crimp characteristics. Become.

The cooled yarn may be wound once or not, and may be used as it is in one or two or more steps at room temperature to 150.
Stretched at ° C. The draw ratio depends on the spinning speed and the required performance of the target staple fiber, and is 2.0
It is set so as to obtain a fiber having a tensile strength of g / d or more and a breaking elongation of 100% or less. Tensile strength is 2.
If it is less than 0 g / d, problems may occur in the processing step, which is not preferable. Further, if the cutting elongation exceeds 100%, the crimping property, particularly the crimping rate becomes poor, and it becomes difficult to put it into practical use.

Next, the above drawn yarn is subjected to a stuffing box method, a pushing heating gear method, a high speed air jet pushing method or the like to obtain 16 to 70 mm / 51 mm, preferably 20 to 60 mm.
A crimp of 51 mm is applied and cut to a length of 20 to 100 mm. In this case, when the number of crimps is less than 16/51 mm, an unopened portion is likely to be generated in the cotton swab process, and 70/51
If it exceeds mm, a nep is likely to occur. In addition, it is necessary to set the crimping degree to be 5.0% or more. If the crimping degree is less than 5.0%, the wrapping property will be poor when it is applied to the card in the next step, and the density of the web will be reduced. Spots are likely to occur.

The staple fiber of the present invention thus obtained has a heat resistance of 120 ° C. or higher and, as described above, has excellent crimping property, strong elongation property and biodegradability. . Incidentally, the staple fiber has a single fiber fineness of 1.0 to 20 denier, and if the single fiber fineness is less than 1.0 denier, the card passability at the time of producing a card web may be poor, or The web obtained using short fibers has many spots,
On the other hand, if the single fiber fineness exceeds 20 denier, the nonwoven fabric obtained by using the short fibers has a coarse and hard texture and is inferior in quality.

The lactic acid-based copolyester is preferably dried by a dryer before spinning and supplied to the spinning machine.
Although an appropriate spinning temperature varies depending on the lactic acid-based copolyester used, it is desirable that the spinning temperature be such that it can flow. Further, the difference in melting point between the lactic acid-based copolyester having a high melting point and the lactic acid-based copolyester having a lower melting point used in the present invention needs to be 20 to 50 ° C.

If the difference between the melting points is less than 20 ° C., it is difficult to perform heat fusion, and a film-like structure is formed, which causes the entire fusion. Also,
When the difference in melting point exceeds 50 ° C., spinning becomes difficult, the nozzle is likely to break at the exit, and the drawability is poor.

When spinning the lactic acid-based copolyester of the present invention, an antioxidant, a heat stabilizer, an ultraviolet absorber, a lubricant, waxes, a coloring agent, a crystallization accelerator, etc. can be used in combination, if necessary. Of course. That is, as antioxidants, hindered phenolic antioxidants such as ptbutylhydroxytoluene and ptbutylhydroxyanisole, sulfur antioxidants such as distearylthiodipropionate and dilaurylthiodipropionate. Agents,

Examples of heat stabilizers include triphenyl phosphite, trilauryl phosphite, and trisnonyl phenyl phosphite, and examples of ultraviolet absorbers include pt-butylphenyl salicylate, 2-hydroxy-4-methoxybenzophenone, and 2-hydroxy-4-methoxybenzophenone. Hydroxy-4-methoxy-
2'-carboxybenzophenone, 2,4,5-trihydroxybutyrophenone, etc., lubricants include calcium stearate, zinc stearate, barium stearate, sodium palmitate, etc.

Examples of the antistatic agent include N, N-bis (hydroxyethyl) alkylamine, alkylamine, alkylallyl sulfonate and alkyl sulfonate.
As flame retardants, hexabromocyclododecane, tris-
(2,3-dichloropropyl) phosphate, pentabromophenyl allyl ether and the like can be mentioned.

The nonwoven fabric composed of the short fibers in the present invention uses the short fibers described above as raw cotton and is carded using a cotton spinning machine to prepare a card web, and the card web thus obtained is subjected to a heat-bonding treatment. This is applied to partially heat bond the constituent fibers. Alternatively, the obtained card web is subjected to a high-pressure liquid flow treatment to three-dimensionally entangle the constituent fibers, and then subjected to a heat-bonding treatment to partially heat-bond the three-dimensionally entangled constituent fibers. Can be obtained.

A publicly known method can be adopted for partially heat-bonding the web. For example, the web is passed between a heated embossing roller and a roller such as a metal roller having a smooth surface, a method using a hot air drying device, or a method using an ultrasonic fusing device.

When the fibers present in the embossed pattern portion are partially heat-bonded by using the heated embossing roller, the pressure contact area ratio of the embossing roller is set to 5 to 50%, and the pressure contact area ratio is less than 5%. If so, the dot-like fused area is small and the mechanical strength of the non-woven fabric is lowered, and good dimensional stability cannot be obtained.
If it exceeds%, the nonwoven fabric becomes rigid and the flexibility is impaired, which is not preferable.

The roller temperature is usually set to a temperature about 5 to 50 ° C. lower than the melting point of the lactic acid-based copolyester having a low melting point. By appropriately selecting this temperature, the adhesive force between fibers becomes high. That is, it is possible to obtain a non-woven fabric having excellent mechanical strength and dimensional stability and being highly flexible.

The embossing pattern in the case of using the heat embossing roller is not particularly limited as long as the pressure contact area ratio is within the range of 5 to 50%, and is round, elliptic, rhombic,
Any shape such as a triangular shape, a T shape, and a well shape may be used.

When the fibers are partially heat-bonded to each other at the crossing points of the fibers by using a hot air dryer, the treatment temperature usually depends on the treatment time, but usually the lactic acid-based copolyester having a low melting point is used. The temperature is preferably about 10 ° C. lower than the melting point of the lactic acid-based copolyester having a melting point or higher and a high melting point. In addition, these partial heat-bonding treatments using, for example, a hot embossing roller, a hot-air drying device, or an ultrasonic fusing device may be either continuous processes or separate processes.

When the web is subjected to the high pressure liquid flow treatment, a known method can be adopted. For example, the hole diameter is 0.05 to 1.0 mm, especially 0.1 mm to 0.4 mm
The injection pressure is 5 ~ 1
There is a method of ejecting a high-pressure liquid of 50 kg / cm ² G from the ejection hole.

The injection holes are arranged in a direction orthogonal to the traveling direction of the web. This treatment may be performed on either one side or both sides of the web. In particular, in the case of one side treatment, the injection holes are arranged in a plurality of rows and the injection pressure is lowered in the previous stage and increased in the latter stage. By doing so, it is possible to obtain a nonwoven fabric having a uniform and dense entangled form and a uniform texture.

As the high speed liquid, water or warm water is generally used. The distance between the injection hole and the web is
It is good to be 1 to 15 cm. If this distance is less than 1 cm, the texture of the web is disturbed, while this distance is 15 cm.
If it exceeds, the impact force when the liquid flow collides with the web is reduced and the three-dimensional entanglement is not sufficiently performed, which is not preferable. This high-speed liquid flow treatment may be either a continuous process or a separate process.

Excess water is removed from the web after it has been subjected to a high pressure liquid stream treatment. When removing this excess water,
A known method can be adopted. For example, a squeezing device such as a mangle roll is used to remove excess water to some extent, and then a drying device such as a continuous hot air dryer is used to remove residual water.

The lactic acid-based copolyester non-woven fabric obtained in the present invention has no odor and has excellent physical properties.
Since it has good biodegradability, it can be used as a heat retention / water retention / curing / bird protection sheet, mulch film, sheet for planting roots, agricultural materials such as fertilizer bags, civil engineering materials such as vegetation sheets, diapers and sanitary products. It is useful in a wide range of applications such as sanitary materials, disposable hand towels, wiping cloths, base materials for pap materials, filters for air purifiers, etc.

In particular, this non-woven fabric is hydrolyzed and decomposed by microorganisms when it is discarded in the soil or dumped in the sea. Even when decomposed in seawater, the strength of the non-woven fabric deteriorates within a few months, and when it is further taken, it decomposes to the extent that the outer shape is not maintained.

[0098]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. All parts in the examples are on a weight basis unless otherwise specified. Also, the molecular weight shown in the examples,
Melting point, spinnability, fineness, processability of nonwoven fabric, dimensional stability, mechanical strength, flexibility, heat resistance, storage stability, biodegradability, etc. were determined by the following methods.

Molecular weight: determined by gel permeation chromatography (GPC) in terms of polystyrene. Melting point (° C): Differential scanning calorimeter DSC-2 manufactured by Seiko
The melting point was the temperature at which the melting endothermic curve obtained by the measurement was measured using a No. 00 type at a temperature rising rate of 10 ° C./min.

Spinnability: The case where there was no yarn breakage during continuous spinning for 1 hour was regarded as good. Fineness: Measured according to the method described in JIS-L-1013. Processability of non-woven fabric: When the web was made by passing through a card machine, the state of generation of unopened parts and neps and the case where there were few density spots were considered good.

Dimensional stability: sample length and sample width are 30c each
Five sample pieces of m were prepared, and the area shrinkage rate (%) was measured when each sample piece was wet-dried three times. Regarding the treatment conditions, the wet treatment temperature was room temperature, the treatment time was 30 minutes, the dry treatment temperature was room temperature, and the treatment time was 24 hours. At this time, the area S1 of the sample piece before the wet / dry treatment and the area S2 of the test piece after the third wet / dry treatment were obtained, and the obtained S1 and S2 were obtained.
Then, the average value of the values calculated by the following formula was defined as the area shrinkage rate (%). Area shrinkage (%) = (1- (S2 / S1)) × 100

Mechanical Strength: KGSM Tensile Strength of Nonwoven Fabric (Kg / 5 cm) Measured according to the method described in JIS-L-1096A. Flexibility: The sensory test evaluated the following four levels. ⊚: Soft and excellent in texture. ○: Soft and good texture. Δ: Slightly hard, texture is insufficient. X: Hard and poor texture.

Heat resistance: The temperature at which the nonwoven fabric was deformed was determined in an oven. Storage stability: 35 ° C x 80% for the obtained non-woven fabric
The state of deterioration in mechanical strength after standing for 1 month in humidity was evaluated according to the following 4 grades. A: No change. ◯: Almost no change. Δ: Slight decrease. X: Significantly reduced.

Biodegradability test: capacity of 10 installed outdoors
Using 0 liter Shinki Gosei composting container Tombo Miracle Compo 100 type, put 50 kg of garbage in it, put a sample of non-woven fabric of 10 cm x 10 cm, and put the garbage into a thickness of about 5 cm. I put it in. On top of that, 500 g of Nyxaminone, a fermentation accelerator manufactured by Aron Kasei Co., Ltd.
Sprinkled with.

One month after the start of the test, the test piece was taken out,
Evaluation was made in the following four stages. ⊚: Tattered to a state where the original shape was not retained. ○: The original shape was retained, but it became brittle. Δ: Changes were observed, but decomposition did not proceed to the point of disintegration. X: No change at all.

Calorific Value of Combustion: The calorific value of combustion of the lactic acid-based copolyesters used in Examples and Comparative Examples of the present invention was a favorable value of about 5,000 cal / g.

(Production of Lactic Acid-Based Polyester) Reference Example 1 30 parts of aliphatic polyester (adipic acid 50 mol%, 1,6-hexanediol 50 mol%, weight average molecular weight 45,000) and pyromellitic dianhydride 0 .3
Parts were added, and the mixture was stirred at 200 ° C. for 3 hours for reaction to obtain a polymer having a weight average molecular weight of 122,000.

Furthermore, 64 parts of L-lactide, D, L-
6 parts of lactide and 15 parts of toluene as a solvent were added, and melt-mixed at 170 ° C. for 1 hour in an inert gas atmosphere. After adding 0.03 part of tin octanoate as a catalyst and reacting for 6 hours, 200 Pellets were formed while removing volatile components at a degree of vacuum of 5 ° C. and 5 mmHg. The lactic acid-based copolyester obtained had a weight average molecular weight of 160,000, a number average molecular weight of 73,000 and a melting point of 153 ° C.

Reference Example 2 5 parts of an aliphatic polyester (50 mol% succinic acid, 50 mol% ethylene glycol, weight average molecular weight 42,000), 95 parts of L-lactide,
And 15 parts of toluene as a solvent and melt-mixed at 170 ° C. for 1 hour in an inert gas atmosphere, 0.03 parts of tin octanoate as a catalyst was added, and the reaction was carried out for 6 hours. After adding 3 parts and further reacting for 1 hour, pelletization was performed while removing volatile components at 200 ° C. and a reduced pressure of 5 mmHg. The resulting lactic acid-based copolyester had a weight average molecular weight of 172,000, a number average molecular weight of 86,000 and a melting point of 168 ° C.

Reference Example 3 To 5 parts of an aliphatic polyester (25 mol% terephthalic acid, 25 mol% isophthalic acid, 20 mol% ethylene glycol, 30 mol% neopentyl glycol, weight average molecular weight 55,400) was added L- Lactide (85 parts), D, L-lactide (10 parts), and toluene (15 parts) as a solvent were added to the mixture under an inert gas atmosphere to give 170.
Melt and mix at ℃ for 1 hour, add 0.03 parts of tin octoate as a catalyst and react for 6 hours, then add 0.2 parts of pyrophosphoric acid and react for another 1 hour, then 200 ℃, 5m
Pelletization was performed while removing volatile matter at a reduced pressure of mHg. The obtained lactic acid-based copolyester had a weight average molecular weight of 178,000, a number average molecular weight of 94,000 and a melting point of 148 ° C.

(Reference Example 4) Aliphatic polyester (40 mol% of dodecane dicaribonic acid, 10 mol% of adipic acid,
1,4-Butanediol 50 mol%, weight average molecular weight 4
5,000) 35 parts, L-lactide 63 parts, D-lactide 2 parts, and toluene 15 parts as a solvent were added, and the mixture was melt-mixed at 170 ° C. for 1 hour under an inert gas atmosphere to give octanoic acid as a catalyst. After adding 0.03 part of tin and reacting for 6 hours, pelletization was performed while removing volatile components at 200 ° C. and a reduced pressure of 2 mmHg. The obtained lactic acid-based copolyester had a weight average molecular weight of 118,000, a number average molecular weight of 57,000 and a melting point of 157 ° C.

Reference Example 5 L-lactide 7 was added to 20 parts of an aliphatic polyester (sebacic acid 50 mol%, propylene glycol 50 mol%, weight average molecular weight 38,000).
8 parts, D-lactide 2 parts, and toluene 15 as a solvent
Part, and at 170 ° C. for 1 hour in an inert gas atmosphere,
After melt-mixing, 0.03 part of tin octanoate as a catalyst was added and reacted for 6 hours, and then pelletized while removing volatile matter at 200 ° C. and a reduced pressure of 2 mmHg. The weight average molecular weight of the obtained lactic acid-based copolyester was 136,0.
00, number average molecular weight 68,000, melting point 158 ° C.

Reference Example 6 Aliphatic polyester (50 mol% of dodecanedicarboxylic acid, neopentyl glycol 5)
0 mol%, weight average molecular weight 38,000) To 20 parts of hexamethylene diisocyanate, add 0.1 part of 130 ° C.
Stir at room temperature for 3 hours to react, weight average molecular weight 78,000
Was obtained.

To this, 72 parts of L-lactide, 8 parts of D, L-lactide, and 10 parts of toluene as a solvent were added, and the mixture was melt-mixed at 170 ° C. for 1 hour in an inert gas atmosphere. Of 0.03 part was added and reacted for 6 hours, then 0.2 part of tartaric acid was further added and reacted for 1 hour, and then pelletized while removing volatile components at 200 ° C. and a reduced pressure of 5 mmHg. The lactic acid-based copolyester obtained had a weight average molecular weight of 156,000, a number average molecular weight of 83,000, and a melting point of 166 ° C.

Reference Example 7 L-lactide 55 was added to 40 parts of an aliphatic polyester (50 mol% sebacic acid, 50 mol% ethylene glycol, weight average molecular weight 45,000).
Parts, D, L-lactide 5 parts, and toluene 1 as a solvent
5 parts were added, and the mixture was melt-mixed at 170 ° C. for 1 hour in an inert gas atmosphere. After adding 0.03 part of tin octanoate as a catalyst and reacting for 5 hours, a mixture of monododecyl phosphate and didodecyl phosphate was added. 0.2 part was added, and the mixture was further reacted for 1 hour, and then pelletized while removing volatile matter at 200 ° C. and a reduced pressure of 5 mmHg. The obtained lactic acid-based copolyester had a weight average molecular weight of 128,000, a number average molecular weight of 64,000 and a melting point of 163 ° C.

Reference Example 8 20 parts of an aliphatic polyester (50 mol% of succinic acid, 25 mol% of ethylene glycol, 25 mol% of polypropylene glycol having a molecular weight of 1000, and a weight average molecular weight of 46,000) and 70 parts of L-lactide were used.
Parts, 10 parts of D, L-lactide, and 10 parts of toluene as a solvent were added, and the mixture was melted and mixed at 170 ° C. for 1 hour in an inert gas atmosphere, and tin octoate 0.03 was used as a catalyst.
Part, and after reacting at 175 ° C. for 6 hours, 0.3 part of trimellitic anhydride was added and reacted at the same temperature for 1 hour, and then pelletized while removing volatile components at 200 ° C. and a reduced pressure of 5 mmHg while removing volatile matter. Turned into The lactic acid-based copolyester obtained had a weight average molecular weight of 150,000 and a number average molecular weight of 7
The melting point was 3,000 and the melting point was 142 ° C.

Reference Example 9 Aliphatic polyester (Azelaic acid 50 mol%, ethylene glycol 15 mol%, tripropylene glycol 35 mol%, weight average molecular weight 4)
1,000) 20 parts, L-lactide 76 parts, D, L-
Add 4 parts of lactide and 15 parts of toluene as a solvent, melt-mix for 1 hour at 170 ° C. in an inert gas atmosphere, add 0.03 part of tin octanoate as a catalyst and react for 5 hours, then anhydrous pyromellitic 0.3 part of acid was added, and the mixture was reacted for 1 hour and then pelletized while devolatilizing.

100 parts of the obtained pellets were blended with 0.4 part of ethylenediaminetetraacetic acid and then melt-kneaded using a vented extruder set at 200 ° C. while melting and kneading.
It was devolatilized at a reduced pressure of mmHg. The obtained lactic acid-based copolyester had a weight average molecular weight of 165,000, a number average molecular weight of 75,000 and a melting point of 158 ° C.

Reference Example 10 Aliphatic polyester (49 mol% of methylsuccinic acid, 1 mol% of maleic anhydride, 2,
3-butanediol component 50 mol%, weight average molecular weight 4
4,000) 20 parts, L-lactide 80 parts, and toluene as a solvent 15 parts are added, and an inert gas atmosphere is added.
Melt and mix at 170 ° C. for 1 hour, add 0.03 parts of tin octoate as a catalyst and react for 5 hours, then add 0.4 parts of triethylenetetramine hexaacetic acid and react for another 1 hour, then 200 ° C. Pelletization was performed while removing volatile components at a reduced pressure of 5 mmHg. The obtained lactic acid-based copolyester had a weight average molecular weight of 156,000, a number average molecular weight of 74,000 and a melting point of 168 ° C.

Reference Example 11 Aliphatic polyester (49 mol% sebacic acid, 1 mol% maleic anhydride, 2,3-
Butanediol 50 mol%, weight average molecular weight 45,000
0) 15 parts, 80 parts L-lactide and 5 parts glycolide,
And 8 parts of toluene as a solvent, and melt-mixed at 170 ° C. for 1 hour in an inert gas atmosphere. After adding 0.03 part of tin octanoate as a catalyst and reacting for 5 hours, monoethylhexylphosphonic acid of 0.1. After adding 2 parts and reacting for 1 hour, it was pelletized while devolatilizing.

The pellets thus obtained were dispersed in methanol at room temperature, stirred, separated and dried to remove volatile matter. The weight average molecular weight of the obtained lactic acid-based copolyester was 16
3,000, number average molecular weight 81,000, melting point 144 ° C
Met.

Reference Example 12 20 parts of aliphatic polyester (50 mol% of methylsuccinic acid, 25 mol% of propylene glycol, 25 mol% of polyethylene glycol / polypropylene glycol block copolymer having a molecular weight of 1000, and weight average molecular weight of 52,000) And L-lactide 7
5 parts, 5 parts of ε-caprolactone, and 8 parts of toluene as a solvent were added, and the mixture was melt-mixed at 170 ° C. for 1 hour in an inert gas atmosphere, and 0.03 part of tin octoate was added as a catalyst and reacted for 5 hours. After that, 0.3 part of aluminum isopropoxide and 0.3 part of ethylenediaminetetraacetic acid were added and reacted for 1 hour, and then pelletized while devolatilizing.

The obtained pellets were dispersed in acetone at room temperature, stirred, separated and dried to remove volatile matter. Weight average molecular weight is 158,000, number average molecular weight is 86,000,
The melting point was 142 ° C.

Reference Example 13 To 25 parts of an aliphatic polyester (50 mol% sebacic acid, 50 mol% 1,4-butanediol, weight average molecular weight 46,000), polylactic acid (95 mol% L-lactic acid, D -Lactic acid 5 mol%, weight average molecular weight 193,000) 75 parts and toluene 1 as solvent
5 parts were added, and the mixture was stirred and dissolved at 170 ° C. for 1 hour in an inert gas atmosphere, and tin octoate was added as a catalyst to 0.0
After adding 3 parts and reacting for 7 hours, it was pelletized while devolatilizing.

After 100 parts of the obtained pellets was blended with 0.5 part of aluminum isopropoxide, it was devolatilized at a reduced pressure of 5 mmHg while melting and kneading using an extruder with a vent set to 200 ° C. The resulting lactic acid-based copolyester had a weight average molecular weight of 148,000, a number average molecular weight of 68,000 and a melting point of 160 ° C.

Reference Example 14 3 mol% of sebacic acid, 4 mol% of propylene glycol and 96 mol% of L-lactic acid were charged into a reaction kettle and heated from 150 ° C. to 7 ° C. in 1 hour under an inert gas atmosphere. While stirring with heating. The temperature was raised to 200 ° C. while distilling off the produced water, and when the distilling of water stopped, 0.007 part of tetraisopropoxytitanium was added as a transesterification catalyst, and the mixture was stirred under reduced pressure up to 0.5 torr.

210 ° C. after the distillation of glycol stopped
For 1 hour. The obtained polyester 100
0.2 part of a mixture of monooctadecyl phosphate and dioctadecyl phosphate was added to each part and reacted at 170 ° C. for 1 hour, and then volatile components were removed at 200 ° C. and a reduced pressure of 5 mmHg to pelletize. . Its weight average molecular weight is 11
8,000, number average molecular weight 62,000, melting point 146 ° C
Met.

(Example 1) The dried lactic acid-based copolyester obtained in Reference Example 1 was supplied to a screw type extruder, the nozzle hole diameter was 0.3 mm, the number of holes was 72, and the spinning temperature was 210 ° C. Melt spinning was performed at a take-up speed of 600 m / min. Next, this yarn was drawn 2.5 times in a warm water bath at 90 ° C. to have a fineness of 1.5 d, a strength of 4.0 g / d and an elongation of 30%.
A lactic acid-based copolyester fiber (A) was obtained.

The lactic acid-based copolyester fiber (A)
After crimping the fibers to a fiber length of 51 mm, fibers are supplied to a random webber to create a web, which is then entangled by a high-pressure liquid flow, with a basis weight of 40 g / cm ³ , and a length x width of 30 cm.
A 30 cm non-woven fabric was obtained. Processability of fibers and nonwovens,
Tables 1 and 2 show performance evaluation results such as dimensional stability, mechanical strength, flexibility, heat resistance, storage stability, and biodegradability.

Examples 2 to 14 Instead of the lactic acid-based copolyester obtained in Reference Example 1, the lactic acid-based copolyester obtained in Reference Example 2 to Reference 14 was used. A lactic acid-based copolyester fiber and a nonwoven fabric thereof were prepared in the same manner as in Example 1. Tables 1 and 2 show performance evaluation results of fibers and nonwoven fabrics such as processability, dimensional stability, mechanical strength, flexibility, heat resistance, storage stability, and biodegradability.

(Example 15) The dried lactic acid-based copolyester obtained in Reference Example 2 was supplied to a screw type extruder, the nozzle hole diameter was 0.3 mm, the number of holes was 72, the spinning temperature was 210 ° C, and the winding was performed. Melt spinning was performed at a speed of 600 m / min. Next, this spun yarn was drawn 3.5 times in a warm water bath at 90 ° C. to obtain a fineness of 1.5 d, a strength of 4.3 g / d and an elongation of 20.
% Lactic acid-based copolyester fiber (A) was obtained. On the other hand, the same polyester as described above was used and the same screw type extruder as described above was supplied, and the nozzle hole diameter was 0.3 mm and the number of holes was 7
2. Melt spinning was performed at a spinning temperature of 210 ° C. and a winding speed of 600 m / min, and the fineness was 3 d, strength was 1.5 g / d, and elongation was 100%.
To obtain an unstretched lactic acid-based polyester fiber (B).

The lactic acid-based copolyester fiber (A)
40% of unstretched lactic acid-based copolyester fiber (B) is mixed with 60% and supplied to a random web bar to prepare a web, which is then heated and pressed by a conventional method to give a lactic acid-based copolyester. Basis weight 4 in which unstretched lactic acid-based copolyester fiber (B) is melted and bonded between fibers (A)
A non-woven fabric having a length of 30 cm and a width of 30 cm was obtained at 0 g / cm ³ .

(Example 16) A low melting point lactic acid-based copolyester obtained in Reference Example 8 using a composite fiber spinning facility comprising two uniaxial extruders and a multifilament nozzle having a hole diameter of 0.5 mmφ and a number of holes of 24. When (C) was used as a sheath component and lactic acid-based copolyester (D) having a higher melting point than the copolymer obtained in Reference Example 10 was used as a core component, spinning was performed at a spinning temperature of 210 ° C. and a take-up speed of 600 m / min. A core-sheath fiber having a yarn denier of 6d was obtained. In this core-sheath fiber, the core component and the sheath component were concentrically arranged, and the cross-sectional area ratio was 1: 1.

This multifilament was drawn at a draw ratio of 2.5 times by a staple fiber trial facility, oiled, crimped, dried, crimped with hot air at 100 ° C., cut, and cut into single yarn denier 3d. Cut length 51
mm, crimp number 15 / inch, and crimp rate 17% were obtained. This composite fiber was passed through a sample card machine having a width of 350 mm three times to prepare a web having a basis weight of 40 g / m ² . This web was placed on a wire mesh belt having a width of 350 mm and a speed of 5 m / min, and the composite fibers were heat-fused with hot air having a temperature of 150 ° C. to prepare a nonwoven fabric.

COMPARATIVE REFERENCE EXAMPLE 1 To 100 parts of L-lactide, 0.03 part of tin octoate as a catalyst and 15 parts of toluene as a solvent were added, and the mixture was added to 170 parts under an inert gas atmosphere.
After reacting at 6 ° C for 6 hours, the mixture was pelletized while removing volatile components at 200 ° C and a reduced pressure of 5 mmHg. The weight average molecular weight of the obtained lactic acid-based copolyester was 166,0.
00, the number average molecular weight was 76,000, and the melting point was 164 ° C.

Comparative Reference Example 2 L-lactide 50 parts, D
-To 50 parts of lactide, 0.0% of tin octoate is used as a catalyst.
3 parts and 15 parts of toluene as a solvent were added, and the mixture was reacted at 170 ° C. for 6 hours in an inert gas atmosphere, and then pelletized while devolatilizing. The obtained pellets were dispersed in methanol at room temperature, stirred, separated and dried to remove volatile components. The weight average molecular weight is 138,000, the number average molecular weight is 69,
000.

(Comparative Reference Example 3) 49 mol% of succinic acid component and 51 mol% of 1,4-butanediol component were charged into a reaction kettle and heated from 150 ° C. to 7 hours per hour in an inert gas atmosphere.
The mixture was heated and stirred while the temperature was raised by ° C. The temperature was raised to 220 ° C. while distilling off the produced water, and 70 ppm of titanium tetraisopropoxide was added as a transesterification catalyst when the distilling of water was stopped, and the mixture was stirred under reduced pressure to a maximum of 0.5 torr.

230 ° C. after the distillation of glycol is stopped
For 1 hour. The obtained polyester 100
Hexamethylene diisocyanate component to 0.
After adding 5 parts and reacting for 1 hour, 200 ° C., 5 mmH
Pelletization was performed while removing volatile matter at a vacuum degree of g. The weight average molecular weight of the obtained lactic acid-based copolyester is 1
36,000, number average molecular weight 41,000, melting point 10
8 ° C.

(Comparative Examples 1 to 3) Regarding the polyesters obtained in Comparative Reference Examples 1 to 3, fibers and nonwoven fabrics were prepared in the same manner as in Example 1 and their performances were evaluated. Table 1 shows the results
And Table 2 below.

[0140]

[Table 1]

[0141]

[Table 2]

[0142]

INDUSTRIAL APPLICABILITY The present invention is a lactic acid-based compound which has a low calorific value of combustion, biodegradability, and excellent flexibility, mechanical strength, heat resistance, moldability, dimensional stability and storage stability. A non-woven fabric made of copolyester can be provided.

Claims (9)

[Claims] 1. A lactic acid component (A), a dicarboxylic acid component (B) and a diol component (C) are contained as structural units.
A nonwoven fabric made of lactic acid-based copolyester having a melting point of 110 ° C to 190 ° C. 2. The lactic acid-based copolyester according to claim 1, which contains a lactic acid component (A), a dicarboxylic acid component (B), a diol component (C) and a high molecular weight agent (D) as structural units. Non-woven fabric. 3. The high molecular weight agent (D) is one or more compounds selected from the group consisting of polycarboxylic acids, metal complexes, epoxy compounds, isocyanates, acidic phosphoric acid esters, and chelating agents. A non-woven fabric comprising the lactic acid-based copolyester according to claim 2, which is characterized. 4. The lactic acid according to any one of claims 1 to 3, wherein the dicarboxylic acid component (B) and the diol component (C) are an aliphatic dicarboxylic acid component and an aliphatic diol component. Non-woven fabric made of copolyester. 5. The dicarboxylic acid component (B) and the diol component (C) have a branched chain.
5. A non-woven fabric comprising the lactic acid-based copolyester according to any one of 1 to 3. 6. The dicarboxylic acid component (B) and the diol component (C) are an aliphatic dicarboxylic acid component and an aliphatic diol component, and have a branched chain. A non-woven fabric comprising the lactic acid-based copolyester according to any one of the above. 7. The lactic acid-based copolyester yarn which is obtained by melt-spinning the lactic acid-based copolyester and then heat-treating the obtained yarn in the temperature range of 60 ° C. to 150 ° C. A non-woven fabric comprising the lactic acid-based copolyester according to any one of 6 above. 8. A yarn made of lactic acid-based copolyester is used as a binder, which is mixed with a yarn made of lactic acid-based copolyester having a melting point 20 ° C. to 50 ° C. higher than that of the lactic acid-based copolyester used in the binder. A non-woven fabric comprising the lactic acid-based copolyester according to any one of claims 1 to 7, wherein the yarns are bonded together. 9. A core-sheath type composite short yarn in which the core part is made of lactic acid-based copolyester and the sheath part is made of lactic acid-based copolyester having a melting point lower than that of the lactic acid-based copolyester, The non-woven fabric made of the lactic acid-based copolyester according to any one of claims 1 to 7, wherein the yarns are partially heat-bonded to each other.