JP2014047319A - Resin composition and use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition obtainable from biodegradable resin, which has an excellent balance of mechanical properties such as Young's modulus, elongation at break, stress at break, etc. and has an excellent formability, and provide use of the resin composition such as mowing cord, etc.SOLUTION: A resin composition according to the present invention is obtained by melt mixing polyglycolic acid and partially aromatic polyester with at least one agent selected from reactive modifier and reactive compatibilizer, and a mowing cord according to the present invention is formed from the resin composition.

Description

  The present invention relates to a resin composition and use thereof.

  Conventionally, a metal blade is used for a mowing portion of a mowing machine, and mowing is performed by rotating the metal blade. However, with a mower using a metal blade, an accident that cuts the foot or hand, sometimes an accident that severely cuts the foot or hand, has occurred due to the foot or hand touching the rotating metal blade.

  In order to solve such a problem, a cord-type mower capable of cutting grass by rotating a resin cord instead of a metal blade has been developed and put into practical use. When cutting a resinous cord at high speed, the cutting force is smaller than when using a metal blade, so the foot or hand touches the rotating resinous cord. It was possible to avoid accidents that would cause serious injuries.

  In current cord type mowers, nylon cords are mainly used as resin cords. Nylon cords had sufficient cutting force to mow the grass and were excellent in durability, but it was not possible to completely prevent the nylon cord from being cut or worn during use. It was inevitable that nylon cords and fragments thereof would diffuse into nature. However, since nylon is hardly decomposed in nature, when a nylon cord and fragments thereof are diffused in nature, there is a risk of being left semi-permanently, which is problematic from the viewpoint of environmental protection.

In order to solve the above problem, it has been proposed to use a biodegradable resin as the resin.
For example, it has been proposed to use a cord made of a biodegradable resin having a tensile modulus of elasticity of 10 MPa or more and 100 MPa or less for a cord type mower (see, for example, Patent Document 1).

  The mowing cord disclosed in Patent Document 1 uses a biodegradable resin such as polybutylene succinate, 1,4-butanediol / succinic acid / lactic acid copolymer, polybutylene adipate, polylactic acid, and tensile elasticity. The rate is in the above range.

However, the mowing cord having the tensile elastic modulus specified by Patent Document 1 has a problem that it is inferior in durability.
Conventionally proposed mowing cords using biodegradable resins do not have the same strength and durability as nylon, and improvements have been desired.

JP 2008-46 A

  The present invention has been made in view of the above-mentioned problems of the prior art, and is a biodegradable resin that has excellent balance of mechanical properties such as Young's modulus, elongation at break, and stress at break, and excellent moldability. An object of the present invention is to provide a resin composition obtained from the above, and to provide uses of the resin composition such as a mowing cord.

  The inventors of the present invention provide a resin composition obtained by melt-kneading polyglycolic acid and a partially aromatic polyester with at least one selected from a reactive modifier and a reactive compatibilizing agent. The present invention has been completed.

  That is, the resin composition of the present invention is obtained by melt-kneading polyglycolic acid and a partially aromatic polyester with at least one selected from a reactive modifier and a reactive compatibilizer.

  At least one selected from the reactive modifier and the reactive compatibilizer is at least one selected from a polyvalent isocyanate compound, a polycarbodiimide, a polyvalent glycidyl compound, an acid anhydride, and a peroxide. Are preferred, polyisocyanate compounds are more preferred, and diisocyanate compounds are particularly preferred.

A molded body such as a monofilament of the present invention comprises the resin composition.
The mowing cord of the present invention comprises the monofilament.

  The resin composition of the present invention has an excellent balance of mechanical properties such as Young's modulus, elongation at break, and stress at break, and is excellent in moldability. Moreover, the mowing cord of the present invention produced from the resin composition has excellent durability.

It is a conceptual diagram of a bending process. It is the schematic which shows the test method at the time of performing durability evaluation of a mowing cord.

Next, the present invention will be specifically described.
The resin composition of the present invention is obtained by melt-kneading polyglycolic acid and a partially aromatic polyester with at least one selected from a reactive modifier and a reactive compatibilizer.

[Polyglycolic acid]
The polyglycolic acid used in the present invention is a homopolymer or copolymer having a repeating unit represented by the following general formula (1).

前記ポリグリコール酸の、上記一般式（１）で表わされる繰り返し単位の含有割合は、５０質量％以上であり、７０質量％以上であることが好ましく、８５質量％以上であることがより好ましく、９５質量％以上であることが更に好ましく、９８質量％以上であることが特に好ましく、最も好ましくは９９質量％以上である実質的にポリグリコール酸のホモポリマーである。

The content ratio of the repeating unit represented by the general formula (1) in the polyglycolic acid is 50% by mass or more, preferably 70% by mass or more, more preferably 85% by mass or more, It is more preferably 95% by mass or more, particularly preferably 98% by mass or more, and most preferably 99% by mass or more of a substantially polyglycolic acid homopolymer.

  When the polyglycolic acid is a copolymer, the content of the repeating unit other than the repeating unit represented by the general formula (1) is 50% by mass or less, and preferably 30% by mass or less. It is more preferably 15% by mass or less, further preferably 5% by mass or less, and particularly preferably 2% by mass or less. Moreover, as said polyglycolic acid, the homopolymer of polyglycolic acid whose content rate of repeating units other than the repeating unit represented by the said General formula (1) is 1 mass% or less is preferable.

Within the said range, since the polyglycolic acid is excellent in strength and biodegradability, it is preferable.
The polyglycolic acid used in the present invention is usually a crystalline polymer having a melting point. Such polyglycolic acid can be produced, for example, by a method of polycondensing glycolic acid, glycolic acid alkyl ester, or glycolate. Polyglycolic acid can also be produced by ring-opening polymerization of glycolide.

  Such polycondensation or ring-opening polymerization can be carried out by a known method, and is not particularly limited, but is usually carried out in the presence of a catalyst. The type of the catalyst is not particularly limited. For example, tin compounds such as tin halides (for example, tin dichloride and tin tetrachloride) and organic carboxylates (for example, tin octoate and tin octylate); alkoxy titanates And titanium compounds such as alkoxyaluminum; zirconium compounds such as zirconium acetylacetone; antimony compounds such as antimony halide and antimony oxide;

  In order to produce a copolymer of glycolic acid as polyglycolic acid, monomers such as glycolide or glycolic acid and various comonomers are copolymerized. Examples of the comonomer include lactide, lactones (for example, β-propiolactone, β-butyrolactone, pivalolactone, γ-butyrolactone, δ-valerolactone, β-methyl-δ-valerolactone, ε-caprolactone), trimethylene. Cyclic monomers such as carbonate and 1,3-dioxane; hydroxycarboxylic acids such as lactic acid, 3-hydroxypropanoic acid, 3-hydroxybutanoic acid, 4-hydroxybutanoic acid and 6-hydroxycaproic acid or alkyl esters thereof; ethylene glycol; Mention may be made of a substantially equimolar mixture of an aliphatic diol such as 1,4-butanediol and an aliphatic dicarboxylic acid such as succinic acid or adipic acid or an alkyl ester thereof. These comonomers may be used individually by 1 type, and may be used in mixture of 2 or more types.

  Among these comonomers, cyclic monomers such as lactide, caprolactone, and trimethylene carbonate; hydroxycarboxylic acids such as lactic acid, and the like are preferable because they are easily copolymerized and a copolymer having excellent physical properties is easily obtained. When glycolide is used as a raw material for polyglycolic acid, it is preferable to use a cyclic monomer such as lactide, caprolactone, trimethylene carbonate as a comonomer. Glycolide and the cyclic monomer can be easily subjected to ring-opening copolymerization. Preferable examples of the polyglycolic acid copolymer include a copolymer of glycolide and lactide, a copolymer of glycolide and caprolactone, and the like. As the lactide, L-lactide is preferable from the viewpoint of availability. As caprolactone, ε-caprolactone is preferred.

  The comonomer is used in such an amount that each repeating unit of the resulting polyglycolic acid is in the above-mentioned range. When the copolymerization ratio of the comonomer increases, the crystallinity of polyglycolic acid tends to be impaired.

  Polyglycolic acid polymerization equipment includes various extruder-type equipment, vertical equipment with paddle blades, vertical equipment with helical ribbon blades, kneader-type horizontal equipment, ampoule-type equipment, and annular-type equipment. The device can be selected as appropriate.

  The polymerization temperature is a temperature within a range of 120 to 300 ° C., which is a substantial polymerization start temperature, and can be set according to the purpose. The polymerization temperature is preferably 130 to 250 ° C, more preferably 140 to 220 ° C, and particularly preferably 150 to 200 ° C. If the polymerization temperature is too high, the resulting polymer is susceptible to thermal decomposition. The polymerization time is in the range of 3 minutes to 20 hours, preferably 5 minutes to 18 hours. If the polymerization time is too short, the polymerization does not proceed sufficiently, and if it is too long, the resulting polymer tends to be colored.

  The weight average molecular weight (Mw) of the polyglycolic acid used in the present invention is usually 30,000 to 800,000, preferably 50,000 to 500,000. The number average molecular weight (Mn) of the polyglycolic acid used in the present invention is usually 10,000 to 800,000, preferably 16,000 to 500,000. In the present invention, the weight average molecular weight (Mw) and the number average molecular weight (Mn) are values converted to polymethyl methacrylate by measurement by gel permeation chromatography (GPC) using a hexafluoroisopropanol solvent.

The melting point of the polyglycolic acid used in the present invention is usually 190 to 225 ° C, preferably 200 to 220 ° C. The polyglycolic acid used in the present invention preferably has a melt viscosity measured at a temperature 50 ° C. higher than the melting point (Tm) (Tm + 50 ° C.) and a shear rate of 122 sec ⁻¹ , usually 50 to 8,000 Pa · s. Is 100 to 5,000 Pa · s, more preferably 200 to 2,000 Pa · s.

(Partial aromatic polyester)
In the present invention, a partially aromatic polyester is used. The partially aromatic polyester is a polyester obtained using a monomer having an aromatic ring as at least one of the monomers, and means having an aromatic ring in the molecule of the polyester.

  The polyester is polymerized using at least one polycarboxylic acid compound selected from polyvalent carboxylic acids and polyvalent carboxylic acid esters and a polyvalent hydroxy compound as monomers. The partially aromatic polyester used in the present invention includes at least one kind of aromatic polyvalent carboxylic acid selected from aromatic polyvalent carboxylic acid and aromatic polyvalent carboxylic acid ester as at least a part of the polyvalent carboxylic acid compound. Preferably, an acid compound is used, or an aromatic polyvalent hydroxy compound is used for at least a part of the polyvalent hydroxy compound, and an aromatic polyvalent carboxylic acid compound is used for at least a part of the polyvalent carboxylic acid compound. It is more preferable.

The partially aromatic polyester is preferably polymerized using the following monomers (a1) to (a3).
((A1) At least one aliphatic dicarboxylic acid compound selected from aliphatic dicarboxylic acid and aliphatic dicarboxylic acid ester)
As the partially aromatic polyester, it is preferable to use at least one aliphatic dicarboxylic acid compound selected from (a1) aliphatic dicarboxylic acid and aliphatic dicarboxylic acid ester as a monomer. In addition, as an aliphatic dicarboxylic acid type compound, you may use 1 type individually or 2 or more types.

The aliphatic group in the present invention includes both chain aliphatic groups and cyclic aliphatic groups.
Examples of the aliphatic dicarboxylic acid include malonic acid, succinic acid, glutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, fumaric acid, and 2,2-dimethyl. Examples include glutaric acid, suberic acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, diglycolic acid, itaconic acid, maleic acid and 2,5-norbornane dicarboxylic acid. It is done.

  Examples of the aliphatic dicarboxylic acid ester include monoalkyl esters and dialkyl esters of the aliphatic dicarboxylic acids. As the alkyl ester, an alkyl ester having an alkyl group having 1 to 6 carbon atoms is preferable.

  The aliphatic dicarboxylic acid-based compound is preferably at least one selected from succinic acid, adipic acid, azelaic acid, sebacic acid, brassic acid, and alkyl esters of these acids, succinic acid, adipic acid, sebacic acid and At least one selected from alkyl esters of these acids is more preferable, and at least one selected from adipic acid and alkyl esters of adipic acid is particularly preferable.

((A2) At least one aromatic dicarboxylic acid compound selected from aromatic dicarboxylic acid and aromatic dicarboxylic acid ester)
As the partial aromatic polyester, (a2) at least one aromatic dicarboxylic acid compound selected from aromatic dicarboxylic acid and aromatic dicarboxylic acid ester is preferably used as a monomer. In addition, as an aromatic dicarboxylic acid type compound, you may use 1 type individually or 2 types or more.

  Examples of the aromatic dicarboxylic acid include aromatic dicarboxylic acids having 8 to 20 carbon atoms, preferably 8 to 12 carbon atoms. As a specific example of the aromatic dicarboxylic acid, at least one selected from terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid and 1,5-naphthalenedicarboxylic acid is particularly preferable.

  Examples of the aromatic dicarboxylic acid ester include monoalkyl esters and dialkyl esters of the aromatic dicarboxylic acid. As the alkyl ester, an alkyl ester having an alkyl group having 1 to 6 carbon atoms is preferable.

The aromatic dicarboxylic acid compound is preferably at least one selected from terephthalic acid and alkyl esters of terephthalic acid.
((A3) Aliphatic dihydroxy compound)
As the partially aromatic polyester, it is preferable to use (a3) an aliphatic dihydroxy compound as a monomer. In addition, as an aliphatic dihydroxy compound, you may use individually by 1 type or 2 or more types.

As the aliphatic dihydroxy compound, a chain aliphatic hydroxy compound having 2 to 12 carbon atoms and a cyclic aliphatic hydroxy compound having 5 to 10 carbon atoms are preferable.
Specific examples of the aliphatic dihydroxy compound include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, , 5-pentanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, 2,2-dimethyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol , 2-ethyl-2-isobutyl-1,3-propanediol, 2,2,4-trimethyl-1,6-hexanediol, and the cycloaliphatic hydroxy compound includes cyclopentanediol, 1,4- Cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexane Sanji methanol or 2,2,4,4-tetramethyl-1,3-cyclobutanediol and the like.

  As the aliphatic dihydroxy compound, ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 2,2-dimethyl-1,3-propanediol (neopentyl glycol) are preferable.

When adipic acid is used as the aliphatic dicarboxylic acid compound, it is preferable to use 1,4-butanediol.
The partially aromatic polyester is preferably a polyester having structural units derived from the monomers (a1) to (a3).

  When the monomers of the above (a1) to (a3) are used when the partially aromatic polyester is produced by polymerization, when the total of (a1) and (a2) is 100 mol%, (a1) It is preferable to use 10 to 90 mol% and 90 to 10 mol% of (a2). Moreover, as the usage-amount of the said monomer of (a3), it is preferable that the sum total of (a3) :( a1) and (a2) is 1: 0.3-1: 2.0.

  When the partially aromatic polyester used in the present invention is a polyester having structural units derived from the monomers (a1) to (a3), monomers other than the monomers (a1) to (a3) (hereinafter referred to as other monomers). It may have a structural unit derived from a monomer.

Other monomers include, for example, compounds containing sulfonate groups, polyether polyols, hydroxycarboxylic acids, cyclic esters of hydroxycarboxylic acids, amino-alkanols, amino-cycloalkanols, diamino-alkanes, bisoxazolines, aminocarboxylic acids, poly Examples thereof include oxazoline, a compound having at least three groups capable of forming an ester in the molecule, an isocyanate group-containing compound, and divinyl ether. As other monomers, one kind may be used, or two or more kinds may be used.
The sulfonate group of the compound containing a sulfonate group may be neutralized with a metal salt. Examples of the compound containing a sulfonate group include a dicarboxylic acid containing a sulfonate group, an alkali metal salt of the compound, Examples include alkaline earth metal salts of compounds, or ester derivatives thereof. Specific examples include 5-sulfoisophthalic acid or an alkali metal salt thereof.

  Examples of the polyether polyol include diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, and polytetrahydrofuran (poly-THF), and diethylene glycol, triethylene glycol, and polyethylene glycol are preferable.

  Examples of the hydroxycarboxylic acid and the cyclic ester of hydroxycarboxylic acid include glycolic acid, lactic acid, 6-hydroxyhexanoic acid, glycolide, dilactide, p-hydroxybenzoic acid, and oligomers or polymers thereof. Further, 3-polyhydroxybutyric acid, polyhydroxyvaleric acid, and polylactide may be used.

  Examples of the amino-alkanol and amino-cycloalkanol include 2-aminoethanol, 3-aminopropanol, 4-aminobutanol, 5-aminopentanol, 6-aminohexanol, aminocyclopentanol, aminocyclohexanol, 4- Aminomethylcyclohexane methanol is mentioned.

Examples of the diamino-alkane include 1,4-diaminobutane, 1,5-diaminopentane, and 1,6-diaminohexane.
The bisoxazoline is a compound having two oxazoline rings, specifically, 2,2′-bis (2-oxazoline), bis (2-oxazolinyl) methane, 1,2-bis (2-oxazolinyl). ) Ethane, 1,3-bis (2-oxazolinyl) propane, 1,4-bis (2-oxazolinyl) butane.

  As the aminocarboxylic acid, for example, a natural aminocarboxylic acid can be used. Natural amino acids include valine, leucine, isoleucine, threonine, methionine, phenylalanine, tryptophan, lysine, alanine, arginine, aspartamic acid, cysteine, glutamic acid, glycine, histidine, proline, serine, tyrosine, asparagine, Glutamine is mentioned.

  The compound having at least three groups capable of forming an ester in the molecule preferably has a total of 3 to 10 groups capable of forming an ester such as a carboxyl group and a hydroxyl group in the molecule. In addition, what a carboxyl group exists as an acid anhydride group may be used, and in this case, one acid anhydride group is regarded as two carboxyl groups.

  Examples of the compound having at least three groups capable of forming an ester in the molecule include tartaric acid, citric acid, malic acid; trimethylolpropane, trimethylolethane; pentaerythritol; polyethertriol; glycerin; trimesic acid; trimellitic acid, Examples include trimellitic anhydride; pyromellitic acid, pyromellitic dianhydride; hydroxyisophthalic acid.

Examples of the isocyanate group-containing compound include aromatic diisocyanates and aliphatic diisocyanates.
Examples of the aromatic diisocyanate include toluylene-2,4-diisocyanate, toluylene-2,6-diisocyanate, 2,2′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, naphthylene- Examples include 1,5-diisocyanate and xylylene-diisocyanate.

  Examples of the aliphatic diisocyanate include 1,6-hexamethylene diisocyanate, isophorone diisocyanate, or methylene-bis (4-isocyanatocyclohexane).

  Examples of the divinyl ether include 1,4-butanediol-divinyl ether, 1,6-hexanediol-divinyl ether, and 1,4-cyclohexanedimethanol-divinyl ether.

  In addition to the monomers (a1) to (a3) described above, polymerization can be performed using the other monomers, whereby a branched structure can be introduced into the resulting partially aromatic polyester.

Moreover, when using another monomer, 0.1-15 mass parts is normally used with respect to a total of 100 mass parts of the monomer of said (a1)-(a3).
The partially aromatic polyester used in the present invention is generally biodegradable.

There is no limitation in particular as the polymerization method of the partial aromatic polyester used for this invention, It can carry out by a conventionally well-known method.
Moreover, as a partial aromatic polyester, you may use a commercial item. As a commercially available product, for example, Ecoflex F BLEND C1200 (manufactured by BASF) can be used.

  The partially aromatic polyester used in the present invention preferably has a number average molecular weight (Mn) in the range of 1000 to 100,000 g / mol. Moreover, as said partial aromatic polyester, it is preferable that melting | fusing point is the range of 60-170 degreeC.

[At least one selected from reactive modifiers and reactive compatibilizers]
In the present invention, at least one selected from a reactive modifier and a reactive compatibilizer is used.

As at least one selected from the reactive modifier and the reactive compatibilizer, known ones known as reactive modifiers and reactive compatibilizers can be used.
Examples of at least one selected from the reactive modifier and the reactive compatibilizer include polyvalent isocyanate compounds, polycarbodiimides, polyvalent glycidyl compounds, acid anhydrides and peroxides. A polyvalent isocyanate compound, a polyvalent glycidyl compound, and a peroxide are preferable, and a polyvalent isocyanate compound is more preferable. In addition, as at least 1 type selected from a reactive modifier and a reactive compatibilizer, 1 type may be individual, or 2 or more types may be used.

  The polyvalent isocyanate compound may be a compound having at least 2, preferably 2 to 3 isocyanate groups in the molecule. Examples of the polyvalent isocyanate compound include polyvalent isocyanate compounds represented by the following formulas (2) to (8).

（式（２）において、Ｒはそれぞれ独立に、−（ＣＨ₂）_n−であり、ｎは１〜６の整数を示す。）

(In the formula (2), R is independently, - (CH _{2) n} - and is, n is an integer of 1-6.)

（式（３）において、ＲおよびＲ₂はそれぞれ独立に、−（ＣＨ₂）_n−であり、ｎは１〜６の整数を示す。）

(In the formula (3), R, and R ₂ is independently, - (CH _{2) n} - and is, n is an integer of 1-6.)

（式（４）において、Ｒはそれぞれ独立に、−（ＣＨ₂）_n−であり、ｎは１〜６の整数を示し、Ｒ₃は炭素数１〜６のアルキル基である。）

(In Formula (4), R is independently, - (CH _{2) n} - and is, n represents an integer of 1-6, R ₃ is an alkyl group having 1 to 6 carbon atoms.)

（式（５）において、Ｒはそれぞれ独立に、−（ＣＨ₂）_n−であり、ｎは１〜６の整数を示す。）

(In the formula (5), R is independently, - (CH _{2) n} - and is, n is an integer of 1-6.)

（式（６）において、Ｒはそれぞれ独立に、−（ＣＨ₂）_n−であり、ｎは１〜６の整数を示す。）

(In the formula (6), R is independently, - (CH _{2) n} - and is, n is an integer of 1-6.)

（式（７）はイソホロンジイソシアネートである。）

(Formula (7) is isophorone diisocyanate.)

（式（８）はキシレンジイソシアネートである。）
また、前記多価イソシアネートとしては、市販品を用いてもよく、例えばデュラネート ＴＰＡ−１００（イソシアヌレート）（多価イソシアネート）（旭化成ケミカルズ製）、デュラネート Ｄ２０１（二官能イソシアネート）（旭化成ケミカルズ製）、デュラネート Ｅ４０２−８０Ｂ（アダクト）（多価イソシアネート）（旭化成ケミカルズ製）、デュラネート Ｐ３０１−７５Ｅ（アダクト）（多価イソシアネート）（旭化成ケミカルズ製）、デュラネート ２４Ａ−１００（ビウレット）（多価イソシアネート）（旭化成ケミカルズ製）、タケネート５００（キシレンジイソシアネート）（三井化学製）を用いることができる。

(Formula (8) is xylene diisocyanate.)
Moreover, as said polyvalent isocyanate, you may use a commercial item, for example, duranate TPA-100 (isocyanurate) (polyhydric isocyanate) (made by Asahi Kasei Chemicals), duranate D201 (bifunctional isocyanate) (made by Asahi Kasei Chemicals), Duranate E402-80B (adduct) (polyvalent isocyanate) (Asahi Kasei Chemicals), Duranate P301-75E (adduct) (polyvalent isocyanate) (Asahi Kasei Chemicals), Duranate 24A-100 (biuret) (polyvalent isocyanate) (Asahi Kasei) Chemicals) and Takenate 500 (xylene diisocyanate) (Mitsui Chemicals) can be used.

In addition, it is preferable from a viewpoint of the moldability of a resin composition to use a diisocyanate compound as a polyvalent isocyanate compound.
The polycarbodiimide may have a plurality of carbodiimide structures (—N═C═N—) in the molecule. Examples of the polycarbodiimide include polycarbodiimide represented by the following formula (9).

（式（９）において、ｎは２〜１００の整数を示す。）
また、前記ポリカルボジイミドとしては、市販品を用いてもよく、例えばカルボジライトＬＡ−１（脂肪族ポリカルボジイミド）（日清紡ケミカル製）、スタバクゾールＰ（芳香族ポリカルボジイミド）（ラインケミー社製）を用いることができる。

(In formula (9), n represents an integer of 2 to 100.)
Moreover, as said polycarbodiimide, you may use a commercial item, for example, using carbodilite LA-1 (aliphatic polycarbodiimide) (made by Nisshinbo Chemical), stavaxol P (aromatic polycarbodiimide) (made by Rhein Chemie). it can.

  The polyvalent glycidyl compound may be a compound having at least 2, preferably 2 to 100 glycidyl groups in the molecule. Examples of the polyvalent glycidyl compound include polyvalent glycidyl compounds represented by the following formulas (10) and (11).

（式（１０）はグリセロールジグリシジルエーテルである。）

(Formula (10) is glycerol diglycidyl ether.)

（式（１１）はネオペンチルグリコールジグリシジルエーテルである。）
また、前記多価グリシジル化合物としては、市販品を用いてもよく、例えばＡＲＵＦＯＮ ＵＧ−４０３５（アクリル／スチレン−ＣＯ−グリシジルメタクリレート）（東亜合成製）、ＡＲＵＦＯＮ ＵＧ−４０４０（アクリル／スチレン−ＣＯ−グリシジルメタクリレート）（東亜合成製）、マープルーフＧ−０２５０Ｓ（スチレン−ＣＯ−グリシジルメタクリレート）（日本油脂製）、エピオールＮＰＧ−１００（ネオペンチルグリコールジグリシジルエーテル）（日油製）を用いることができる。

(Formula (11) is neopentyl glycol diglycidyl ether.)
Moreover, as said polyvalent glycidyl compound, you may use a commercial item, for example, ARUFON UG-4035 (acrylic / styrene-CO-glycidyl methacrylate) (made by Toa Gosei), ARUFON UG-4040 (acrylic / styrene-CO-). Glycidyl methacrylate (manufactured by Toa Gosei), Marproof G-0250S (styrene-CO-glycidyl methacrylate) (manufactured by NOF Corporation), Epiol NPG-100 (neopentyl glycol diglycidyl ether) (manufactured by NOF Corporation) can be used. .

  The acid anhydride may be a compound having at least 2, usually 2 to 100 acid anhydride groups in the molecule. As an acid anhydride, the acid anhydride represented, for example by the following formula | equation (12) is mentioned.

（式（１２）は無水ピロメリット酸である。）
前記過酸化物としては、分子内に少なくとも過酸化物構造（−Ｏ−Ｏ−）を有している化合物であればよい。過酸化物としては、例えば以下の式（１３）、（１４）で表される過酸化物が挙げられる。

(Formula (12) is pyromellitic anhydride.)
The peroxide may be a compound having at least a peroxide structure (—O—O—) in the molecule. Examples of the peroxide include peroxides represented by the following formulas (13) and (14).

〔樹脂組成物〕
本発明の樹脂組成物は、前述のポリグリコール酸および部分芳香族ポリエステルを、前述の反応性改質剤および反応性相溶化剤から選択される少なくとも一種と溶融混練することにより得られる。

(Resin composition)
The resin composition of the present invention can be obtained by melt-kneading the aforementioned polyglycolic acid and the partially aromatic polyester with at least one selected from the aforementioned reactive modifier and reactive compatibilizing agent.

The melt kneading can be performed using a known kneader such as a plastograph, a single screw extruder, a twin screw extruder, a Banbury mixer, and the like.
The melt kneading is usually performed in the range of 220 to 290 ° C, preferably in the range of 230 to 270 ° C.

  In addition, a solid resin composition can be obtained by melt-extruding, cooling and solidifying after melt-kneading. Further, drying, heat treatment or the like may be performed after melt extrusion. Further, the resin composition of the present invention can be obtained in a desired shape by appropriately selecting the conditions for melt extrusion. Examples of the shape of the resin composition include yarns and pellets.

  The amount of the polyglycolic acid and the partially aromatic polyester used for obtaining the resin composition of the present invention is usually 10 to 90% of the polyglycolic acid when the total of the polyglycolic acid and the partially aromatic polyester is 100% by mass. Mass%, partially aromatic polyester is 90 to 10 mass%, preferably polyglycolic acid is 20 to 80 mass%, partially aromatic polyester is 80 to 20 mass%, more preferably polyglycolic acid is 30 to 30 mass%. 70 mass%, and partially aromatic polyester is 70-30 mass%. The said range is preferable from a viewpoint of the balance of the mechanical physical property of a resin composition.

  Further, the amount of at least one selected from the reactive modifier and the reactive compatibilizer used when obtaining the resin composition of the present invention is 100 parts by mass of the total of polyglycolic acid and partially aromatic polyester. Then, it is 0.1-5.0 mass parts normally, Preferably it is 0.2-3.0 mass parts, More preferably, it is 0.2-2.0 mass parts. The said range is preferable from a viewpoint of the balance of the mechanical physical property of a resin composition, and a moldability.

  The resin composition of the present invention can be obtained by melt-kneading in the presence of at least one selected from the above-mentioned polyglycolic acid, partially aromatic polyester, reactive modifier and reactive compatibilizer. The resin composition of the present invention is excellent in the balance of mechanical properties such as Young's modulus, elongation at break, and stress at break, and is excellent in moldability and can be used for various applications. Moreover, since the raw material is principally biodegradable including polyglycolic acid, the resin composition of the present invention is biodegradable.

  In addition, since the resin composition of this invention is obtained through melt-kneading, it is thought that the reactive modifier and the reactive compatibilizing agent are reacting with the above-mentioned polyglycolic acid and partially aromatic polyester.

  Specifically, a hydroxyl group or carboxyl group possessed by polyglycolic acid, a hydroxyl group or carboxyl group possessed by a partially aromatic polyester, and a functional group possessed by at least one selected from a reactive modifier and a reactive compatibilizing agent It is considered that a block copolymer is formed by reacting and bonding. More specifically, when a diisocyanate compound such as xylylene diisocyanate is used as at least one selected from a reactive modifier and a reactive compatibilizing agent, a hydroxyl group possessed by polyglycolic acid or a partially aromatic polyester It is considered that a block copolymer bonded with a urethane bond is formed by reacting with the hydroxyl group possessed by.

  Moreover, various additives may be contained in the resin composition of the present invention. Examples of additives include plasticizers, modifiers, fillers, lubricants, ultraviolet absorbers, antioxidants, stabilizers, pigments, colorants, antistatic agents, mold release agents, fragrances, antibacterial agents, and others. Examples thereof include resins.

These may be added before melt kneading, or may be added after melt kneading.
In addition, when the additive is contained in the resin composition of this invention, when the whole resin composition shall be 100 mass parts, an additive is contained normally in 0.01-50 mass parts. .

[Use of resin composition]
The resin composition of the present invention is excellent in the balance of mechanical properties such as Young's modulus, elongation at break, and stress at break, and is excellent in moldability and can be used for various applications.

  Since the resin composition of the present invention is excellent in moldability as described above, various molded products can be obtained. Specifically, using the resin composition of the present invention, it is possible to produce molded articles such as monofilaments such as mowing cords, pipes for building materials, and inflation films.

  When the resin composition of the present invention is used for a mowing cord, the method for producing the mowing cord is not particularly limited. For example, an undrawn yarn made of the resin composition of the present invention is prepared by melt spinning, and the undrawn yarn There is a method of producing a mowing cord by subjecting to a stretching treatment (primary stretching) to produce a monofilament, followed by a secondary stretching or bending treatment.

  In the primary stretching, it is preferable to stretch the film at a stretching ratio of 2 to 6 times at a temperature of 40 to 80 ° C. Moreover, in the said secondary extending | stretching, it is preferable to extend | stretch to a draw ratio 1.05-1.50 times on the conditions of temperature 20-90 degreeC.

  The mowing cord formed from the resin composition of the present invention has a sufficient cutting force for mowing grass because the resin composition has an excellent balance of mechanical properties such as Young's modulus, elongation at break, and stress at break. And excellent in durability.

  A conventional mowing cord formed using a biodegradable resin has a problem that when it collides with a hard material such as concrete, it breaks at the contact portion between the rotor and the monofilament. The cord has the same or better durability than nylon.

The mowing cord of the present invention usually has a length of 10 to 800 m and a diameter of 1.4 to 3.0 mm.
In the present invention, the bending process means a process of bending a monofilament, and the bending process is usually performed in two or more directions. The bending process is preferably performed in two directions of 0 ° and 180 ° of the circular cross section of the monofilament. Further, the bending process is usually performed under the condition of a temperature of 20 to 90 ° C.

  When the bending process is performed, for example, as shown in FIG. 1, a monofilament is wound around a cylindrical jig and the whole monofilament is bent. The diameter of the cylindrical jig is 0.5 cm to 30 cm, preferably 1 cm to 20 cm. Further, the bending process may be performed using a winder attached to the extruder.

EXAMPLES Next, although an Example is shown and this invention is demonstrated further in detail, this invention is not limited by these.
[Example 1]
70% by mass of polyglycolic acid pellets (manufactured by Kureha) (weight average molecular weight (Mw): 150,000), Ecoflex F BLEND C1200 (manufactured by BASF) (derived from adipic acid, terephthalic acid, and 1,4-butanediol The partially aromatic polyester having a structural unit) was mixed at a ratio of 30% by mass to obtain a mixture (I).

Then, 0.2 parts by mass of Takenate 500 (manufactured by Mitsui Chemicals) (xylene diisocyanate) was mixed with 100 parts by mass of the mixture (I) to obtain a mixture (II).
The obtained mixture (II) was put into a co-rotating meshing twin screw extruder (“TEM-26SS” manufactured by Toshiba Machine Co., Ltd., screw diameter: 26 mm, L / D: 60) from a hopper, and a barrel temperature of 260 ° C. Was melt kneaded.

This molten resin composition was extruded from a die having 3 holes with an outer diameter of 3 mm, and the extruded strand was introduced into a 30 ° C. water bath and cooled and solidified to obtain an undrawn yarn.
The obtained undrawn yarn was vacuum-dried at 50 ° C. for 12 hours and then heat-treated at 80 ° C. for 1 hour. The undrawn yarn (resin composition) thus obtained was cut into a length of 70 mm, and a tensile tester (made by Orientec Co., Ltd.) under the conditions of a temperature of 23 ° C., a humidity of 50% RH and a tensile speed of 200 mm / min. Tensile tests were performed using “RTC-1210A”) to determine Young's modulus, elongation at break, and stress at break.

The results are shown in Table 1.
[Examples 2 to 4]
Except for changing the amount of Takenate 500 used from 0.2 parts by mass to 0.3 parts by mass (Example 2), 0.5 parts by mass (Example 3), and 1.0 parts by mass (Example 4). It carried out similarly to Example 1 and manufactured and evaluated undrawn yarn.

The results are shown in Table 1.
[Comparative Example 1]
70% by mass of polylactic acid (REVODE110) pellets (manufactured by Kaisho Biological Materials) (weight average molecular weight (Mw): 250,000) and 30% by mass of Ecoflex F BLEND C1200 (manufactured by BASF) are mixed. (I) was obtained.

  Thereafter, 1.0 part by mass of Epoxidized Soybean Oil (ESBO) (manufactured by Sajo Haepyo Corporation) was mixed with 100 parts by mass of the mixture (I) to obtain a mixture (II).

  The obtained mixture (II) was put into a co-rotating meshing twin screw extruder (“TEM-26SS” manufactured by Toshiba Machine Co., Ltd., screw diameter: 26 mm, L / D: 60) from a hopper and barrel temperature 185 ° C. Was melt kneaded.

This molten resin composition was extruded from a die having 3 holes with an outer diameter of 3 mm, and the extruded strand was introduced into a 30 ° C. water bath and cooled and solidified to obtain an undrawn yarn.
The obtained undrawn yarn was vacuum-dried at 50 ° C. for 12 hours and then heat-treated at 80 ° C. for 1 hour. The undrawn yarn (resin composition) thus obtained was cut into a length of 70 mm, and a tensile tester (made by Orientec Co., Ltd.) under the conditions of a temperature of 23 ° C., a humidity of 50% RH and a tensile speed of 200 mm / min. Tensile tests were performed using “RTC-1210A”) to determine Young's modulus, elongation at break, and stress at break.

The results are shown in Table 1.
Example 5
The same procedure as in Example 1 was performed except that the amount of polyglycolic acid pellets was changed from 70% by mass to 50% by mass, and the amount of Ecoflex was changed from 30% by mass to 50% by mass. Manufacture and evaluation were performed.

The results are shown in Table 1.
[Examples 6 to 8]
Except for changing the amount of Takenate 500 used from 0.2 parts by mass to 0.3 parts by mass (Example 6), 0.5 parts by mass (Example 7), and 1.0 parts by mass (Example 8). In the same manner as in Example 5, undrawn yarn was produced and evaluated.

The results are shown in Table 1.
[Comparative Example 2]
Production of undrawn yarn was carried out in the same manner as in Comparative Example 1 except that the amount of polylactic acid pellets was changed from 70% by mass to 50% by mass and that of Ecoflex was changed from 30% by mass to 50% by mass. And evaluated.

The results are shown in Table 1.
Example 9
The amount of polyglycolic acid pellets was changed from 70% by mass to 30% by mass, the amount of Ecoflex was changed from 30% by mass to 70% by mass, and the amount of Takenate 500 was changed from 0.2 parts by mass to 0.2% by mass. Except having changed to 5 mass parts, it carried out similarly to Example 1 and manufactured and evaluated undrawn yarn.

The results are shown in Table 1.
Example 10
Except having changed the usage-amount of Takenate 500 from 0.5 mass part to 1.0 mass part, it carried out similarly to Example 9 and manufactured and evaluated undrawn yarn.

The results are shown in Table 1.
[Comparative Example 3]
Production of undrawn yarn was carried out in the same manner as in Comparative Example 1 except that the amount of polylactic acid pellets was changed from 70% by mass to 30% by mass and that of Ecoflex was changed from 30% to 70% by mass. And evaluated.

  The results are shown in Table 1.

前記実施例、比較例から明らかなように、ポリグリコール酸の使用量と、ポリ乳酸の使用量が同様の実施例、比較例では、ポリグリコール酸を用いた方が、各物性が向上している。特に、一般にポリ乳酸よりも硬質な樹脂として知られるポリグリコール酸を用いた本願実施例は、ポリ乳酸を用いた比較例と比べて、伸び（破断点伸度）が大きくなるという予期せぬ効果を有することが分かった。

As is apparent from the above Examples and Comparative Examples, the amount of polyglycolic acid used and the amount of polylactic acid used are the same in Examples and Comparative Examples. Yes. In particular, the present example using polyglycolic acid, which is generally known as a harder resin than polylactic acid, has an unexpected effect of increasing elongation (elongation at break) compared to a comparative example using polylactic acid. It was found to have

Example 11
(Manufacture of resin composition)
Polyglycolic acid pellets (manufactured by Kureha) (weight average molecular weight (Mw): 150,000) were mixed at a ratio of 40% by mass and Ecoflex F BLEND C1200 (manufactured by BASF) at a ratio of 60% by mass to obtain a mixture (I). It was.

Thereafter, Takenate 500 (manufactured by Mitsui Chemicals) was mixed with 0.3 parts by mass with respect to 100 parts by mass of the mixture (I) to obtain a mixture (II).
The obtained mixture (II) was put into a same-direction rotating meshing twin screw extruder (“TEM-26SS” manufactured by Toshiba Machine Co., Ltd., screw diameter 26 mm, L / D = 60) from a hopper at a temperature of 250 ° C. Melt kneaded.

  Subsequently, the molten resin composition was extruded as a strand and solidified by cooling in a 30 ° C. water bath. The obtained strand was pelletized using a pelletizer manufactured by Thermo Plastics.

The obtained pellets were vacuum-dried at 90 ° C. for 12 hours to obtain a raw material for producing a monofilament (resin composition).
(Manufacturing monofilament)
Using the raw material for producing the monofilament, melt spinning was performed at an extrusion temperature of 250 ° C. using a φ35 mm extruder and a φ8 mm nozzle, and then rapidly cooled in water at 5 ° C. to obtain an undrawn yarn.

The undrawn yarn was drawn three times in a 60 ° C. hot water bath, and then heat-treated at 150 ° C. to obtain a monofilament.
(Manufacture of mowing cord)
Next, the monofilament was secondarily drawn 1.1 times under the condition of a temperature of 23 ° C. to obtain a mowing cord (monofilament) having a diameter of 2.4 mm.

The durability of the mowing cord was evaluated by the method described later.
The results are shown in Table 2.
Example 12
(Manufacture of resin composition)
A raw material for producing a monofilament (resin composition) was carried out in the same manner as in Example 11 except that the amount of polyglycolic acid pellets was changed from 40% to 50% by weight and the amount of Ecoflex was changed from 60% to 50% by weight. Product).

(Manufacturing monofilament)
A monofilament was obtained in the same manner as in Example 11 except that the material described in the above item was used as the raw material for producing the monofilament (resin composition).

(Manufacture of mowing cord)
Next, the monofilament was secondarily drawn 1.1 times under the condition of a temperature of 23 ° C. to obtain a mowing cord (monofilament) having a diameter of 2.4 mm.

The durability of the mowing cord was evaluated by the method described later.
The results are shown in Table 2.
Example 13
(Manufacture of resin composition)
It carried out like Example 12 and obtained the raw material for monofilament preparation (resin composition).

(Manufacturing monofilament)
A monofilament was obtained in the same manner as in Example 11 except that the material described in the above item was used as the raw material for producing the monofilament (resin composition).

(Manufacture of mowing cord)
Next, the monofilament was secondarily drawn 1.2 times under the condition of a temperature of 23 ° C. to obtain a mowing cord (monofilament) having a diameter of 2.3 mm.

The durability of the mowing cord was evaluated by the method described later.
The results are shown in Table 2.
Example 14
(Manufacture of resin composition)
It carried out like Example 12 and obtained the raw material for monofilament preparation (resin composition).

(Manufacturing monofilament)
A monofilament was obtained in the same manner as in Example 11 except that the material described in the above item was used as the raw material for producing the monofilament (resin composition).

(Manufacture of mowing cord)
Next, the monofilament was secondarily drawn 1.4 times under the condition of a temperature of 23 ° C. to obtain a mowing cord (monofilament) having a diameter of 2.2 mm.

The durability of the mowing cord was evaluated by the method described later.
The results are shown in Table 2.
Example 15
(Manufacture of resin composition)
It carried out like Example 12 and obtained the raw material for monofilament preparation (resin composition).

(Manufacturing monofilament)
A monofilament was obtained in the same manner as in Example 11 except that the material described in the above item was used as the raw material for producing the monofilament (resin composition).

(Manufacture of mowing cord)
Next, the monofilament was secondarily stretched 1.1 times under the condition of a temperature of 40 ° C. to obtain a mowing cord (monofilament) having a diameter of 2.4 mm.

The durability of the mowing cord was evaluated by the method described later.
The results are shown in Table 2.
Example 16
(Manufacture of resin composition)
It carried out like Example 12 and obtained the raw material for monofilament preparation (resin composition).

(Manufacturing monofilament)
A monofilament was obtained in the same manner as in Example 11 except that the material described in the above item was used as the raw material for producing the monofilament (resin composition).

(Manufacture of mowing cord)
Next, the monofilament was secondarily drawn 1.2 times under the condition of a temperature of 40 ° C. to obtain a mowing cord (monofilament) having a diameter of 2.3 mm.

The durability of the mowing cord was evaluated by the method described later.
The results are shown in Table 2.
Example 17
(Manufacture of resin composition)
It carried out like Example 12 and obtained the raw material for monofilament preparation (resin composition).

(Manufacturing monofilament)
A monofilament was obtained in the same manner as in Example 11 except that the material described in the above item was used as the raw material for producing the monofilament (resin composition).

(Manufacture of mowing cord)
Next, the monofilament was secondarily stretched 1.1 times under the condition of a temperature of 60 ° C. to obtain a mowing cord (monofilament) having a diameter of 2.4 mm.

The durability of the mowing cord was evaluated by the method described later.
The results are shown in Table 2.
Example 18
(Manufacture of resin composition)
It carried out like Example 12 and obtained the raw material for monofilament preparation (resin composition).

(Manufacturing monofilament)
A monofilament was obtained in the same manner as in Example 11 except that the material described in the above item was used as the raw material for producing the monofilament (resin composition).

(Manufacture of mowing cord)
Next, the monofilament was secondarily stretched 1.2 times under the condition of a temperature of 60 ° C. to obtain a mowing cord (monofilament) having a diameter of 2.3 mm.

The durability of the mowing cord was evaluated by the method described later.
The results are shown in Table 2.
Example 19
(Manufacture of resin composition)
It carried out like Example 12 and obtained the raw material for monofilament preparation (resin composition).

(Manufacturing monofilament)
A monofilament was obtained in the same manner as in Example 11 except that the material described in the above item was used as the raw material for producing the monofilament (resin composition).

(Manufacture of mowing cord)
Next, the monofilament was secondarily drawn 1.1 times under the condition of a temperature of 80 ° C. to obtain a mowing cord (monofilament) having a diameter of 2.4 mm.

The durability of the mowing cord was evaluated by the method described later.
The results are shown in Table 2.
Example 20
(Manufacture of resin composition)
It carried out like Example 12 and obtained the raw material for monofilament preparation (resin composition).

(Manufacturing monofilament)
A monofilament was obtained in the same manner as in Example 11 except that the material described in the above item was used as the raw material for producing the monofilament (resin composition).

(Manufacture of mowing cord)
Next, the monofilament was secondarily stretched 1.2 times under the condition of a temperature of 80 ° C. to obtain a mowing cord (monofilament) having a diameter of 2.3 mm.

The durability of the mowing cord was evaluated by the method described later.
The results are shown in Table 2.
Example 21
(Manufacture of resin composition)
It carried out like Example 12 and obtained the raw material for monofilament preparation (resin composition).

(Manufacturing monofilament)
A monofilament was obtained in the same manner as in Example 11 except that the material described in the above item was used as the raw material for producing the monofilament (resin composition) and the draw ratio was changed from 3 to 4 times.

(Manufacture of mowing cord)
Next, the monofilament was secondarily drawn 1.1 times under the condition of a temperature of 23 ° C. to obtain a mowing cord (monofilament) having a diameter of 2.4 mm.

The durability of the mowing cord was evaluated by the method described later.
The results are shown in Table 2.
[Example 22]
(Manufacture of resin composition)
It carried out like Example 12 and obtained the raw material for monofilament preparation (resin composition).

(Manufacturing monofilament)
A monofilament was obtained in the same manner as in Example 11 except that the raw material for preparing the monofilament (resin composition) was the same as that described above, and the temperature of the hot water bath was changed from 60 ° C to 75 ° C.

(Manufacture of mowing cord)
Next, the monofilament was secondarily drawn 1.1 times under the condition of a temperature of 23 ° C. to obtain a mowing cord (monofilament) having a diameter of 2.4 mm.

The durability of the mowing cord was evaluated by the method described later.
The results are shown in Table 2.
Example 23
(Manufacture of resin composition)
It carried out like Example 12 and obtained the raw material for monofilament preparation (resin composition).

(Manufacturing monofilament)
Example 11 except that the raw material for monofilament preparation (resin composition) described above was used, the temperature of the hot water bath was changed from 60 ° C. to 75 ° C., and the draw ratio was changed from 3 times to 4 times. In the same manner as above, a monofilament was obtained.

(Manufacture of mowing cord)
Next, the monofilament was secondarily drawn 1.1 times under the condition of a temperature of 23 ° C. to obtain a mowing cord (monofilament) having a diameter of 2.4 mm.

The durability of the mowing cord was evaluated by the method described later.
The results are shown in Table 2.
Example 24
(Manufacture of resin composition)
A raw material for producing a monofilament (resin composition) was carried out in the same manner as in Example 11 except that the amount of polyglycolic acid pellets was changed from 40% to 60% by weight and the amount of Ecoflex was changed from 60% to 40% by weight. Product).

(Manufacturing monofilament)
A monofilament was obtained in the same manner as in Example 11 except that the material described in the above item was used as the raw material for producing the monofilament (resin composition).

(Manufacture of mowing cord)
Next, the monofilament was secondarily drawn 1.1 times under the condition of a temperature of 23 ° C. to obtain a mowing cord (monofilament) having a diameter of 2.4 mm.

The durability of the mowing cord was evaluated by the method described later.
The results are shown in Table 2.
Example 25
(Manufacture of resin composition)
It carried out like Example 12 and obtained the raw material for monofilament preparation (resin composition).

(Manufacturing monofilament)
A monofilament was obtained in the same manner as in Example 11 except that the material described in the above item was used as the raw material for producing the monofilament (resin composition).

(Manufacture of mowing cord)
Next, the monofilament was wound around a cylindrical jig having a diameter of 1 cm as shown in FIG. 1, and a process for bending the entire monofilament (bending process) was performed at an ambient temperature of 23 ° C.

The bending treatment was performed once in the directions of 0 ° and 180 ° of the circular cross section of the monofilament to obtain a monofilament (mowing cord) having a diameter of 2.4 mm.
The durability of the mowing cord was evaluated by the method described later.

The results are shown in Table 2.
Example 26
(Manufacture of resin composition)
It carried out like Example 12 and obtained the raw material for monofilament preparation (resin composition).

(Manufacturing monofilament)
A monofilament was obtained in the same manner as in Example 11 except that the material described in the above item was used as the raw material for producing the monofilament (resin composition).

(Manufacture of mowing cord)
Next, the monofilament was wound around a cylindrical jig having a diameter of 20 cm as shown in FIG. 1, and a treatment (bending treatment) for bending the entire monofilament was performed at an ambient temperature of 23 ° C.

The bending treatment was performed once in the directions of 0 ° and 180 ° of the circular cross section of the monofilament to obtain a monofilament (mowing cord) having a diameter of 2.4 mm.
The durability of the mowing cord was evaluated by the method described later.

The results are shown in Table 2.
[Comparative Example 4]
A nylon cord (manufactured by Maruyama Seisakusho) (2.4 mm in diameter) was prepared as a mowing cord.

The durability of the mowing cord was evaluated by the method described later.
The results are shown in Table 2.
[Comparative Example 5]
Ecoflex F BLEND C1200 (manufactured by BASF) was melt-spun at a temperature of 200 ° C. using a φ35 mm extruder and a φ8 mm nozzle, and then rapidly cooled in water at 5 ° C. to obtain an undrawn yarn.

The undrawn yarn was drawn three times in a 60 ° C. water bath, and then heat treated at 100 ° C. to obtain a monofilament.
Next, the monofilament was stretched 1.1 times under the condition of 23 ° C. to obtain a monofilament (mowing cord) having a diameter of 2.4 mm.

The durability of the mowing cord was evaluated by the method described later.
The results are shown in Table 2.
[Durability evaluation of mowing cord]
A manual rotor manufactured by Starting Engineering Co., Ltd. was mounted on the rotating part of an engine brush cutter FCG22EASP (S) manufactured by Hitachi Koki.

The mowing cords manufactured in Examples and Comparative Examples were mounted so as to come out of the manual rotor by 20 cm, the brush cutter was rotated, and the rotation speed was set to be 1/2 of the maximum speed.
As shown in FIG. 2, it was pressed while adjusting so that the tip of the mowing cord was always in contact with the concrete, and the time until the mowing cord was cut at the contact portion between the rotor and the mowing cord was measured and defined as the endurance time. The results are shown in Table 2.

前記実施例、比較例から明らかなように、本願発明の草刈コードは、従来公知の生分解性樹脂を用いた草刈コード（比較例５）よりも明らかに耐久性に優れ、ナイロンコードを用いた場合（比較例４）と同等あるいは同等以上の耐久性を有しており、草刈コードに好適に用いることができる。また、本発明の草刈コードは、生分解性を有する材料から形成されるため、自然界に破片等が拡散した場合であっても、環境への負荷が小さい。

As is clear from the Examples and Comparative Examples, the mowing cord of the present invention is clearly superior in durability to the mowing cord using a conventionally known biodegradable resin (Comparative Example 5), and uses a nylon cord. It has durability equal to or greater than or equal to the case (Comparative Example 4) and can be suitably used for a mowing cord. In addition, since the mowing cord of the present invention is formed from a biodegradable material, the load on the environment is small even when fragments and the like diffuse into the natural world.

DESCRIPTION OF SYMBOLS 1 ... Mowing cord 3 ... Manual rotor 5 ... Concrete 7 ... Direction of rotation

Claims (7)

  A resin composition obtained by melt-kneading polyglycolic acid and a partially aromatic polyester with at least one selected from a reactive modifier and a reactive compatibilizing agent.   The at least one selected from the reactive modifier and the reactive compatibilizer is at least one selected from a polyvalent isocyanate compound, a polycarbodiimide, a polyvalent glycidyl compound, an acid anhydride, and a peroxide. Item 2. The resin composition according to Item 1.   The resin composition according to claim 1, wherein at least one selected from the reactive modifier and the reactive compatibilizer is a polyvalent isocyanate compound.   The resin composition according to claim 1, wherein at least one selected from the reactive modifier and the reactive compatibilizer is a diisocyanate compound.   The molded object which consists of a resin composition as described in any one of Claims 1-4.   The monofilament which consists of a resin composition as described in any one of Claims 1-4.   A mowing cord comprising the monofilament according to claim 6.

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