WO2005003450A1 - Process for production of aliphatic polyester composition, pulp and cellulosic fiber to be used therein, and process for microfibrillation thereof - Google Patents

Abstract

A fiber/biodegradable resin composite material having high rigidity and high strength can be produced by dispersing a fiber component in a resin component finely and uniformly by a general-purpose kneading means without pretreatment of the resin component. Namely, such a composite material can be produced by melt-kneading together 1 to 99.9 parts by weight of a resin component consisting of 1 to 100 wt% of (A) an aliphatic polyester and 99 to 0 wt% of (B) polylactic acid and 99 to 0.1 parts by weight of a fiber component consisting of (C) pretreated pulp and/or cellulosic fiber with scratches on the outer layers of primary and secondary walls in the presence of (D) a swelling agent capable of swelling the noncrystalline region of cellulose. During the melt kneading, the fiber component is microfibrillated through opening and dispersed in the resin component uniformly and finely.

Description

 Specification

 Method for producing aliphatic polyester composition, pulp and cellulosic fiber used therefor, and microfibrillic method therefor

 Field of the invention

 [0001] The present invention is used in the field of household goods and packaging materials, and after being disposed of, is biologically decomposed by microorganisms in a natural environment such as in soil, and finally is completely dissolved in carbon dioxide gas and water. A method for industrially producing a high-strength, high-rigidity aliphatic polyester composition, which is an environmentally friendly, biodegradable aliphatic polyester composition which is degraded, The present invention relates to a treated pulp and / or a cellulosic fiber and a microfibrillating method thereof.

 Background of the Invention

 [0002] As a high-rigidity, high-strength biodegradable composite material, a composite material of a plant fiber and a biodegradable resin has been studied. For example, JP-A-06-345944 and JP-A-2002-292608 disclose that a pulp or a cellulosic fiber is dispersed in a biodegradable resin to obtain a biodegradable composite material having excellent rigidity. It states that it can.

 [0003] It is known that a composite material composed of a thermoplastic resin and a fiber is controlled by an aspect ratio of a fiber dispersed in the material such as mechanical strength. In order to obtain cellulosic fibers having a high aspect ratio, a method of forming microfibrils utilizing the hydrophilicity characteristic of pulp or cellulosic fibers is disclosed in Japanese Patent Publication Nos. 48-6641 and 50-38720. It is described in the gazette, where the pulp is highly and repeatedly ground or beaten with a refiner or a homogenizer to obtain microfibrillated cellulose fibers.

[0004] It is difficult to finely disperse pulp or cellulosic fibers in a biodegradable resin. In order to uniformly and finely disperse them in a biodegradable resin, the raw material of the biodegradable resin must be finely divided in advance. Alternatively, it is necessary to form a fine fiber. That is, a composite material in which pulp or cellulosic fibers are finely dispersed cannot be obtained without previously pulverizing or degrading the biodegradable resin into fine powder or fine fibers. Be sure to biodegrade A complicated pretreatment such as pulverization or fibrous formation of a conductive resin composite material is required.

 [0005] The production of such a plant fiber / biodegradable resin composite material requires a complicated process such as a wet kneading process, a wet compression molding process, and a subsequent drying process. It is not possible to apply a plastic resin device or a molding process. As a result, a great deal of energy is expended, and the resulting composite material is expensive, so that practical use is difficult. Summary of the Invention

 [0006] The present invention does not require complicated pretreatment of a biodegradable resin or fine fibers of pulp, and employs a general-purpose kneading means to uniformly and finely disperse a fiber component in a resin component. To provide a method for producing a high-strength, high-rigidity biodegradable aliphatic polyester composition from microfibril-like cellulose fibers. Another object of the present invention is to provide a pulp and a cellulosic fiber used in this method and a method for microfibrillating the same.

 [0007] In the method for producing an aliphatic polyester composition of the present invention, (a) an aliphatic polyester obtained by reacting (b) an aliphatic dicarboxylic acid and / or a derivative thereof with an aliphatic diol (A) l-99% by weight of a resin component consisting of 100% by weight and 99-0% by weight of polylactic acid (B), and a pre-treated pulp and / or cell opening having damaged outer layers of primary and secondary walls. 99-0.1 part by weight of the fiber component comprising the staple fiber (C) is melt-kneaded in the presence of the cellulose amorphous region swelling agent (D). However, the total amount of the resin component and the fiber component shall be 100 parts by weight.

[0008] In the present invention, "aliphatic" means "aliphatic" in a broad sense including "alicyclic". The aliphatic polyester (A) is obtained by reacting (a) an aliphatic diol, (b) an aliphatic dicarboxylic acid and / or a derivative thereof, and ( _c ) a bifunctional aliphatic hydroxycarboxylic acid and Z or a derivative thereof. It may be obtained by performing the above.

[0009] The present inventors have found that a pulp and / or a cellulosic fiber in which a primary wall and a secondary wall outer layer have been damaged by pretreatment are subjected to a general-purpose melt-kneading method which does not require pretreatment of a resin component. Microfine fibril-like cellulose fibers are uniformly and finely dispersed in the resin component; thus, a high-rigidity and high-strength composite material can be obtained by a general-purpose molding method. [0010] In the conventional plant fiber / biodegradable resin composite member as described above, the biodegradable resin is preliminarily pulverized or fine fiber in order to uniformly disperse the fiber component in the biodegradable resin. And a great deal of labor was required for the pretreatment for this purpose. In addition, complicated operations were necessary for kneading, molding, and subsequent drying.

 [0011] On the other hand, in order to uniformly disperse the fiber component in a thermoplastic resin, microfibrillation has been performed by repeatedly grinding or beating the fiber component. The microfibrillation of the fiber component requires complicated operations and a great deal of labor in the presence of moisture.In addition, since the microfibrillated fiber is in a slurry state, it must be handled. It is difficult and the supply to the kneader is not always easy. Pre-microfibrillated fibers are less likely to form frogs (agglomerates) during kneading with the resin and to quickly become high aspect ratio fibers.

 [0012] Such a simple pretreatment that does not require a great deal of labor for the pretreatment operation, or a general-purpose kneading means that does not require a special kneading means, enables the fiber component to be contained in the resin component. The present inventors have studied a method of uniformly and finely dispersing the particles. Pulp and / or cellulosic fibers that have been subjected to a simple pretreatment of damaging the outer layers of the primary and secondary walls are melt-kneaded with the resin component in the presence of a cellulose amorphous region swelling agent. It was found that the fiber component was disintegrated into microfibrils, and was uniformly and finely dispersed in the resin component. In other words, pulp and / or cellulosic fibers whose primary and secondary wall outer layers have been damaged by pretreatment are easily defibrated during melt-kneading and are finely dispersed uniformly in the molten resin. Is done. The pulp and / or cellulosic fiber which only damage the outer layers of the primary wall and the secondary wall are easy to handle and kneaded smoothly with the resin.

 [0013] The pulp and the cellulosic fiber of the present invention have damaged primary and secondary wall outer layers, and are used in a method for producing such an aliphatic polyester composition.

 [0014] In the method for microfibrillating pulp of the present invention, the pulp formed by damaging the outer layers of the primary wall and the secondary wall is kneaded in the presence of a swelling agent for the amorphous cellulose region to dissolve the fiber component. Delicate.

[0015] In the method for microfibrillating a cellulosic fiber according to the present invention, the primary wall and the secondary wall outer layer The fiber component is fibrillated by kneading the cellulosic fiber formed by scratching in the presence of the cellulose amorphous region swelling agent.

 According to the method for producing an aliphatic polyester composition of the present invention, the fiber component is simply subjected to a simple pretreatment, which does not require a complicated pretreatment step of the resin component. By dispersing the fiber component uniformly and finely in the resin component, a high-rigidity and high-strength fiber Z biodegradable resin composite material can be manufactured.

 According to the present invention, a high-strength, high-rigidity fiber / biodegradable resin composite molded article can be manufactured using a general-purpose thermoplastic resin kneading means and molding means. INDUSTRIAL APPLICABILITY The present invention can be applied to injection molding equipment for general-purpose thermoplastic resin, extrusion molding of films, sheets, and the like, thereby improving production efficiency and reducing production costs.

 Brief Description of Drawings

 FIG. 1 is a schematic perspective view showing a laminated structure of pulp and cellulosic fibers.

 FIG. 2a is an electron micrograph showing the morphology of the pretreated pulp used in the examples, and FIG. 2b is an electron micrograph showing the morphology of the pulp without pretreatment used in the comparative example.

 FIG. 3a is an electron micrograph showing the morphology of the fiber component in the composition obtained in Example 2, and FIG. 3b is the morphology of the fiber component in the composition obtained in Comparative Example 2. It is an electron microscope photograph shown.

 Preferred embodiments of the invention

 Hereinafter, the method for producing the aliphatic polyester composition of the present invention, the pulp and the cellulosic fibers used therefor, and the method for producing microfibrils thereof will be described in detail.

 [0020] [Aliphatic polyester (A)]

 The aliphatic polyester (A) used in the present invention comprises, under polyester production conditions, (a) an aliphatic diol, (b) an aliphatic dicarboxylic acid and / or a functional derivative thereof, and (c) It is obtained by reacting a bifunctional aliphatic hydroxycarboxylic acid and / or a derivative thereof, and is preferably obtained by performing this reaction in the presence of a germanium catalyst.

[0021] <(a) Aliphatic diol>

The (a) aliphatic diol (including alicyclic diol) used in the present invention has two hydroxyl groups. The preferred specific examples thereof are those represented by the following general formula (I): [0022] HO-R-OH (I)

In the general formula (I), R ¹ is a divalent aliphatic hydrocarbon group, preferably an aliphatic hydrocarbon group having 211 carbon atoms, particularly preferably an aliphatic hydrocarbon group having 2 to 6 carbon atoms. R ¹ may have a branched chain and may be a cycloalkylene group. R ¹ is preferably — (CH 2) n — (only

 And n represents an integer of 2-11, preferably an integer of 26. ).

 [0024] Specific examples of the aliphatic diol (a) that can be used in the present invention include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5_pentanediol, 1, 6-hexanediol, 1,4-cyclohexanediol, 1,6-cyclohexanedimethanol, and the like. These may be used alone or as a mixture of two or more.

 From the viewpoint of the physical properties of the aliphatic polyester (A) obtained, (a) the aliphatic diol is preferably 1,4-butanediol.

 <(B) Aliphatic dicarboxylic acid and / or derivative thereof>

 The (b) aliphatic dicarboxylic acids (including alicyclic dicarboxylic acids) and / or derivatives thereof used in the present invention are those represented by the following general formula (II), or those having a lower carbon number of 114. Forces such as alkyl esters or their anhydrides are not limited thereto.

[0027] HOOC—R ² — COOH… (II)

In the general formula (Π), R ² is a direct bond or a divalent aliphatic hydrocarbon group, preferably a divalent aliphatic hydrocarbon having 211 to 11 carbon atoms, and particularly preferably a divalent aliphatic hydrocarbon having 2 to 6 carbon atoms. Group. R ² may have a branched chain or may be a cycloalkylene group. R ² is preferably — (CH 2) m — (where m represents an integer of 0 or 11-11, preferably an integer of 0 or 116)

2

 It is.

 [0029] Preferable specific examples of the aliphatic dicarboxylic acid include oxalic acid, succinic acid, dataric acid, adipic acid, sebacic acid, suberic acid, dodecane diacid, and the like. Anhydrides, but are not limited thereto.

[0030] These may be used alone or as a mixture of two or more. That is, each group They may be used together and / or between each group.

 From the viewpoint of the physical properties of the aliphatic polyester (A) obtained, (b) aliphatic dicarboxylic acid and / or its derivative may be succinic acid or succinic anhydride, or a mixture of these with adipic acid. Preferably, there is.

 <(C) Bifunctional aliphatic hydroxycarboxylic acid and Z or a derivative thereof>

 The (c) bifunctional aliphatic hydroxycarboxylic acid (including alicyclic hydroxycarboxylic acid) and / or a derivative thereof which can be used in the present invention includes one hydroxyl group in the molecule. There is no particular limitation as long as it has one and one carboxylic acid group, but an aliphatic hydroxycarboxylic acid corresponding to an aliphatic hydroxycarboxylic acid unit of the following general formula (II) is preferable, and Preferable are lower alkyl esters having 14 to 14 carbon atoms or intramolecular esters thereof.

[0033] HO-R ³ -COOH… (ΙΠ)

In the general formula (III), R ³ is a divalent aliphatic hydrocarbon group, preferably a divalent aliphatic hydrocarbon group having 1 to 11 carbon atoms, more preferably a divalent aliphatic hydrocarbon group having 16 carbon atoms. is there. R ³ may be a cycloalkylene group, but is preferably a chain hydrocarbon group. The term “chain” includes not only “linear” but also “branched”.

 (C) The bifunctional aliphatic hydroxycarboxylic acid and / or a derivative thereof is more preferably one in which a hydroxyl group and a carboxy group are bonded to one carbon atom, and represented by the following general formula (IV) Those represented are preferred. The use of a bifunctional aliphatic hydroxycarboxylic acid represented by the following general formula (IV) or a derivative thereof is particularly preferable because the polymerization rate increases.

 [0036] [Formula 1]

HO-CH-COOH _f

 I… (! V)

^ a ⁿ 2a + 1

(In the general formula (IV), a is 0 or an integer of 1 or more, preferably 0 or 110, more preferably 0 or 115.) [0037] Specific examples of the bifunctional aliphatic hydroxycarboxylic acid include lactic acid, glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxy_n_butyric acid, 2-hydroxy-3,3-dimethylbutyric acid, Ratantones such as 2-hydroxy-3-methylbutyric acid, 2-methyllactic acid, 2-hydroxycaproic acid, or ryprotonate may be used. These may be used alone or as a mixture of two or more. When these optical isomers are present, any of the D-form, L-form, and racemic form may be a solid, liquid, or aqueous solution. In particular, lactic acid and an aqueous solution thereof which are particularly remarkable in increasing the polymerization rate during use and are easily available are preferred. Lactic acid is generally commercially available in 50%, 70%, and 90% aqueous solutions, and is easily available. By using lactic acid, the compatibility between the aliphatic polyester (A) and the polylactic acid (B) can be enhanced.

 <Aliphatic polyester (A) and its production>

 The aliphatic polyester (A) used in the present invention comprises the above components (a) and (b) and, if necessary, further the component (c), under the polyester formation conditions, preferably in the presence of a catalyst comprising a germanium compound. It is produced by the following reaction method.

 [0039] The amount of (a) the aliphatic diol used is (b) a force that is substantially equimolar to the aliphatic dicarboxylic acid and / or a derivative thereof. For this reason, the aliphatic diol (a) is used in an excess of 1 to 50 mol, preferably 5 to 30 mol per 100 mol of the aliphatic dicarboxylic acid and / or a derivative thereof (b).

 [0040] When the component (c) is used, the amount of the (c) bifunctional aliphatic hydroxycarboxylic acid and / or the derivative thereof is determined based on (b) 100 mol of the aliphatic dicarboxylic acid and / or a derivative thereof. It is preferably 0.04 to 60 monoles, preferably f to 1 to 20 monoles, and more preferably f to 3 to 10 monoles. (c) If the amount of the bifunctional aliphatic oxycarboxylic acid and Z or a polymer thereof is less than this range, it is difficult to obtain a high molecular weight aliphatic polyester which is less likely to exhibit the effect of improving the polymerization reactivity by using this. If it exceeds this range, the heat resistance and strength become insufficient.

[0041] (c) The timing of adding the bifunctional aliphatic hydroxycarboxylic acid and Z or a derivative thereof is not particularly limited as long as it is before the ester formation reaction. Raw material preparation in the state of being dissolved in acid and / or derivative solution Preferred is a method in which the catalyst is added during the reaction or during the esterification reaction, or a method in which the catalyst is added at the same time as the catalyst is added at the time of charging the raw materials.

 [0042] The production of the aliphatic polyester (A) used in the present invention is preferably carried out in the presence of a germanium compound-based catalyst using the above raw materials.

 [0043] The germanium compound-based catalyst used may be one composed of only one kind of germanium compound or may be one composed of two or more kinds. Also, one or more kinds of germanium compound may be used. Any known catalyst that can be used for the production of polyester, for example, a metal compound catalyst that is soluble in a reaction system such as titanium, antimony, tin, magnesium, zinc, and calcium can be used. As the germanium compound, for example, an organic germanium compound such as tetraalkoxygermanium, or an inorganic germanium compound such as germanium oxide or germanium chloride is particularly preferable. From the viewpoint of price and availability, germanium oxide, tetraethoxygermanium, tetrabutoxygermanium and the like are preferable. The amount of these catalysts used is generally 0.001 to 3% by weight, more preferably 0.005 to 1.5% by weight, based on the amount of monomer used, that is, the total amount of components (a) to (c). %. The timing of adding the catalyst is not particularly limited as long as it is before the production of the polyester, but may be added at the time of charging the raw materials or may be added at the start of reduced pressure. As mentioned above, (c) the ability to be added simultaneously with the bifunctional aliphatic hydroxycarboxylic acid and / or its derivative, or (c) the catalyst to the bifunctional aliphatic hydroxycarboxylic acid and / or its derivative or its aqueous solution when the raw materials are charged. It is preferable to dissolve and add.

[0044] The conditions such as temperature, time, and pressure for producing the aliphatic polyester (A) are not particularly limited as long as the aliphatic polyester (A) as a target product can be obtained. — 260 ° C., preferably 180—230 ° C., polymerization time is 1 hour or more, preferably 215 hours, and the degree of vacuum during the polycondensation reaction is 1.33 × 10 ³ Pa or less, more preferably 0.27. Les, Shi preferable be selected from X 10 ³ Pa follows ranges.

[0045] The aliphatic polyester (A) obtained in this manner has the (a) component and the (b) component as main polyester members. In general, if additives are used, (a) an aliphatic diol unit and (b) an aliphatic dicarboxylic acid When the molar ratio of the (functional derivative) units is substantially equal and the number of moles of all the constituent components of the aliphatic polyester copolymer is 100 moles, (c) the bifunctional aliphatic hydroxycarboxylic acid unit is as follows: Preferably it is 0.02-30 mol. In particular, when the bifunctional aliphatic hydroxycarboxylic acid component (c) is lactic acid, the compatibility between the aliphatic polyester (A) and the polylactic acid (B) can be obtained by introducing the component (c) in such a range. Is very high.

 [0046] The number average molecular weight Mn of the aliphatic polyester (A) used in the present invention is generally from 10,000 to 300,000, usually from 30,000 to 300,000.

 [0047] In the aliphatic polyester (A) used in the present invention, (d) other copolymer components can be introduced as long as the effect is not impaired. (D) It is preferable to add a polyhydric hydroxycarboxylic acid, a polycarboxylic acid, a polyhydric alcohol, or the like having three or more functions as another copolymer component, because the melt viscosity can be increased. Specific examples of such a component include malic acid, trimethylolpropane, glycerin, pentaerythrinoletone, and trimellitic acid.The physical properties of the aliphatic polyester (A) obtained include malic acid. , Trimethylolpropane, glycerin and the like are particularly preferred. Such a proportion of the other copolymer component (d) is preferably 0.0001-3 monoles when the number of moles of all the constituent components of the aliphatic polyester copolymer is 100 mol.

 [0048] [Polylactic acid (Β)]

 The polylactic acid (Β) used in the present invention is not particularly limited, but the number average molecular weight required for having sufficient strength is 30,000 or more, preferably 100,000 or more. The upper limit of the number average molecular weight of the polylactic acid (II) is not particularly limited, but is usually 1,000,000 or less, preferably 500,000 or less. From the physical properties of polylactic acid (Β) obtained, the molar ratio of L-form and D-form constituting polylactic acid (Β) is L / D is 100 / 0—the force that can be used in all compositions of OZlOO High elastic modulus In order to obtain the above, it is preferable that the L-form is 95 mol% or more. The method for producing polylactic acid (B) is not particularly limited, and examples thereof include a ring-opening polymerization method via lactide and a direct polycondensation method of lactic acid.

 [Pretreated pulp and Z or cellulosic fiber (C) in which primary and secondary wall outer layers are damaged]

<Pulp and / or senole mouth fiber> As the pulp and / or cellulosic fiber used in the present invention, kraft pulp, chemically treated pulp of wood such as sulfite pulp, recycled pulp recycled from waste paper, artificial cellulose fiber, bacterial cellulose fiber by acetic acid bacteria, Examples thereof include cellulose fibers derived from animals such as sea squirts and those obtained by chemically modifying them. These may be used alone or in combination of two or more. Of these, pulp obtained from plant-derived wood, waste paper, and the like is preferable in terms of cost and the global environment. Representative chemical modification methods for pulp and / or cellulosic fibers include acetylation and cyanoethylation.

 <Pretreatment of Pulp and / or Cellulosic Fiber>

 As shown in FIG. 1, the pulp and the cellulosic fiber have a laminated structure including a primary wall 1, a secondary wall outer layer 2, a secondary wall middle layer 3, and a secondary wall inner layer 4. In FIG. 1, the thin line in each layer indicates the orientation direction of the microfibrils in the cell opening. The primary wall 1 of the pulp and the outer layer 2 of the secondary wall function as sheaths of the inner layers 3 and 4 in the secondary wall occupying 70-90% of the laminated structure, and the inner layer 3 in the secondary wall 3 4 is tightly united.

 [0051] In a conventional thermoplastic resin-based composite material, in order to completely unravel the sheath-like hulls and microfibrillate the cellulose fibers of the aggregate, it is repeatedly milled several tens of times using a refiner and a high-pressure homogenizer. , Beating. In the present invention, the above-mentioned pulp and / or cellulosic fiber is subjected to a mild pretreatment of damaging the outer layers of the primary and secondary walls, so that the sheath of the outermost layer is easily broken.

 [0052] Examples of the pretreatment method include well-known refiner treatment, medium stirring mill treatment, vibration mill treatment, stone mill treatment, and the like. Refiner treatment is preferred.

 [0053] Semi-chemical pulp obtained by mechanically processing pulp with a refiner, a grinder, or the like is also generally provided. If the pulp satisfies the water retention described below, this semi-chemical pulp can be used as pre-treated pulp. .

[0054] The state of damage to the outer layers of the primary wall and the secondary wall due to such pretreatment is determined by observing the morphology of the pretreated pulp and / or the cellulosic fiber using a microscope, and the water retention of the pretreated pulp and the Z or cellulosic fiber. Can be grasped. The water retention is defined as the water content of a 2% by weight slurry after centrifugation at 1000 G for 15 minutes using a centrifuge. X) is 100% by weight, and the water retention of pulp and cellulosic fiber without pretreatment is usually 100-120%. In the present invention, it is preferable to use pulp and / or cellulosic fibers having a water retention of 150 to 600%, particularly 200 to 400% by pretreatment.

 [0055] The pretreated pulp and the Z or cellulosic fibers (C) are aggregates of cellulose fibers having an average diameter of tens of μm to tens of μm. The melt-kneading with the resin component by a twin-screw extruder described later results in a microfibrillated cellulose having an average diameter of several zm—0.005 xm and a length / diameter ratio (aspect ratio) of 10 or more, for example, 20-200. Is obtained. This microfibrillated cellulose is branched (fibrillated) from the aggregate of the cellulose fibers and uniformly and finely dispersed in the resin component as if it were a spider web.

 [0056] The pulp and the Z or cellulosic fibers that damage the outer layers of the primary wall and the secondary wall may be kneaded without a resin component in the presence of a cellulose amorphous region swelling agent (D) described later. The fibrous component is defibrated and microfibrillated. The pulp and / or cellulosic fiber thus obtained can be effectively used not only for the aliphatic polyester composition but also for various uses.

 [Swelling agent for cellulose amorphous region (D)]

 The cellulose amorphous region swelling agent (D) used in the present invention is a low molecular weight compound having a hydrogen bonding ability with cellulose fibers, and is a cellulose fiber aggregate or a pretreated pulp and / or a cellulosic fiber (C). It is a compound that can be impregnated and diffused into the amorphous region of cellulose fibers.

 [0058] Specific compounds of the cellulose amorphous region swelling agent (D) include water, ethylene glycol, butylene glycol, methyl alcohol, and ethyl alcohol, and preferred are water, ethylene glycol, and methyl alcohol. . These cellulose amorphous region swelling agents (D) may be used alone or as a mixture of two or more.

 [0059] [Aliphatic polyester composition]

 <Blending of aliphatic polyester composition>

In the present invention, the blending ratio of the aliphatic polyester (A), the polylactic acid (B) optionally blended, the pretreated pulp and / or the cellulose fiber (C) is determined by the proportion of the aliphatic polyester ( A): Resin component consisting of a mixture of 100-1% by weight and polylactic acid (B): 0-99% by weight per 119.9 parts by weight of pretreated pulp and / or cellulosic fiber (D) 99-0.1 parts by weight.

 [0060] The aliphatic polyester (A) is inferior in rigidity and heat resistance to the polylactic acid (B), but is preferably a resin component because of its excellent fine dispersibility of the pretreated pulp and / or the cellulosic fiber (C). The content of polylactic acid (B) is 60% by weight based on 40% by weight of the aliphatic polyester (A), and more preferably, 100% to 60% by weight of the aliphatic polyester (A) is 40% by weight of the polylactic acid (). In% by weight. The form of the aliphatic polyester (A) and polylactic acid (B) may be any of granular, powdery, and fibrous, but is preferably granular.

 [0061] Resin component (total of aliphatic polyester (A) and polylactic acid (B)) The ratio of fiber component (pretreated pulp and Z or cellulosic fiber (C)) to 99.9 parts by weight is as follows. , 99-0.1 parts by weight. For a high-rigidity, high-strength composite material, it is desirable to mix a large amount of fiber components, but in this case, the flowability at the time of molding processing is reduced. The preferred compounding ratio is 95 to 3 parts by weight of the fiber component to 5 to 97 parts by weight of the resin component, and more preferably 65 to 5 parts by weight of the fiber component to 35 to 95 parts by weight of the resin component. However, the total of the resin component and the fiber component shall be 100 parts by weight.

 [0062] The aliphatic polyester composition according to the production method of the present invention may contain an aliphatic polyester (A), a polylactic acid (B), a pre-treated pulp and / or a polylactic acid, if necessary, as long as the effects of the present invention are not impaired. Components other than the cellulosic fiber (C), for example, a lubricant, a wax, a colorant, a stabilizer, and other various additives may be blended.

 [0063] The amount of the cellulose amorphous region swelling agent (D) used in the melt kneading with respect to the fiber component, that is, the pretreated pulp and / or the cellulosic fiber (C) may be any amount as long as it is equal to or more than the water retention of the fiber component. From the refining effect in the dispersing step described later and the separability thereafter, it is preferable that the content of the pretreated pulp and / or the cellulosic fiber (C) is 100 to 600% by weight, particularly 200,500% by weight. .

 <Production of Aliphatic Polyester Composition (Melting and Kneading)>

In the present invention, the resin component and the fiber component are melted and kneaded in the presence of the cellulose amorphous region swelling agent (D) using a twin-screw extruder, so that the fiber component is defibrated and the tree is extruded. The aliphatic polyester composition may be produced by uniformly and finely dispersing the fiber component in the fat component.

 Here, the twin-screw extruder used is a device used for mixing, plasticizing, and extruding a general-purpose thermoplastic resin, and the two screws can be rotated in different directions or in the same direction. Is good. Screws can be completely meshed, incompletely meshed, or non-engaged, but the completely meshed type is preferred from the viewpoint of dispersibility of fiber components. If the screw length / screw diameter ratio is 20 70, it is good. Specific twin screw extruders such as “TEX” manufactured by Nippon Steel Works, “TEM” manufactured by Toshiba Machine Co., Ltd., and rzSKj manufactured by Krupp “Werner” can be used.

 [0066] The melt-kneading according to the present invention is preferably performed by using such a twin-screw extruder, for example, through the following step (1) or (2) by a combination of screw constitutions.

 (1) A resin component, a fiber component and a cellulose amorphous region swelling agent are supplied to a twin-screw extruder, and the fiber component is added to the resin component in the twin-screw extruder in the presence of the cellulose amorphous region swelling agent. Defibration and dispersing `` Dispersion process '' followed by melting and dispersing the fiber component in the molten resin component while further melting and finely dispersing the resin component, and then swelling the cellulose amorphous region Separation agent for cellulose amorphous region swelling agent that extrudes kneaded material while separating agent.

 In this case, the defibrating and dispersing steps are preferably performed at a temperature of 30 to 90 ° C. Melting. The dispersing step is preferably performed at a temperature of 120 to 200 ° C. The temperature of the cellulose amorphous region swelling agent separation / extrusion step is preferably 120 to 200 ° C. In addition, the screw rotation speed is preferably in the range of 50 to 400 rpm in all steps. To prevent the hydrolysis of the aliphatic polyester (A) due to the long residence time, the screw length / screw length is required. The smaller the diameter ratio, the more preferable it is 2550.

(2) A melting step in which the resin component is supplied to the twin-screw extruder and the resin component is melted in the twin-screw extruder, and thereafter, the mixture of the fiber component and the cellulose amorphous region swelling agent is biaxially extruded. A fiber 'fibrillation' dispersion process in which the fiber component is fibrillated and finely dispersed in the resin component in the presence of the cellulose amorphous region swelling agent by pressure injection into the machine, and then the cellulose amorphous region swelling agent is separated And swelling agent for cellulose amorphous region extruding the kneaded material. [0070] The melting step is preferably performed at a temperature of 120 to 200 ° C, and the melting 'fibrillation' dispersion step is preferably performed at a temperature of 120 to 180 ° C. The swelling agent separation / extrusion step is preferably performed at a temperature of 120 to 200 ° C. and a pressure of atmospheric pressure and vacuum. The screw rotation speed is preferably in the range of 50 to 400 rpm in all the steps. In the melt 'fibrillation' dispersion step, a mixture of the cellulose amorphous region swelling agent (D) and the fiber component is injected under pressure into a molten resin component at atmospheric pressure of a few MPa using a pump. It is preferable to further perform melting, defibration, and fine dispersion without separating the cellulose amorphous region swelling agent (D). In this case, the ratio of the screw length Z to the screw diameter is preferably 30 to 70.

 [0071] In any of the above methods (1) and (2), the injection of the cellulose amorphous region swelling agent (D) into the twin-screw extruder is premixed with the fiber component and supplied in a liquid state by a pump. If necessary, the cellulose amorphous region swelling agent (D) may be supplied alone in a liquid form. In order to shorten the fiber component, the melt-kneading step may be performed under pressure to prevent evaporation of the cellulose amorphous region swelling agent (D). If necessary, a cellulose amorphous region swelling agent (D) can be added by a pressure pump during the melting step of the resin component. After the melt-kneading, the pressure is released, and the pressure is further reduced, whereby the cellulose amorphous region swelling agent (D) can be separated.

 [0072] The aliphatic polyester composition extruded and granulated in this way does not require a drying step, and only has a preliminary drying for separating water adhering to the surface before molding, which is essential for the polyester resin. Can be used for molding power.

[0073] The properties of the obtained aliphatic polyester composition, that is, the composite material in which the fiber component is uniformly and finely dispersed in the resin component, largely depends on the form of the fiber component dispersed in the resin component. It is preferable that microfibrils are formed, rather than the aggregates. In the present invention, as described above, when the resin component and the fiber component are melt-kneaded, preferably using a twin-screw extruder, in the presence of the cellulose amorphous region swelling agent (D), the resin component becomes As a mixing and kneading medium for aliphatic polyester (A) and polylactic acid (B), fiber components can be defibrated and uniformly finely dispersed in resin components with good mixing and kneading properties. . The cellulose amorphous region swelling agent (D) reduces the cohesive force between cellulose microfibrils in such a melt-kneading step, and causes the aggregate of cellulose fibers to become microscopic. It has the function of defibrating into fibrils and preventing aggregation of the defibrated microfibrillated celluloses, and has the effect of increasing uniform fine dispersibility. However, it is difficult to completely convert the aggregate of cellulose fibers into microfibrils, and the fiber component in the aliphatic polyester composition produced according to the present invention is defibrated from the aggregate of cellulose fibers. There are also aggregates of cellulosic fibers that are made up of only microfibrillated cellulose.

 [0074] Molding method of aliphatic polyester composition>

 As a method for molding the aliphatic polyester composition produced by the method of the present invention, any method similar to the method for molding a usual thermoplastic resin composition can be applied. Specifically, injection molding, extrusion molding, hollow molding, foam molding and the like can be employed.

 [0075] The aliphatic polyester composition according to the present invention has sufficient rigidity and mechanical strength and can be subjected to various molding processes such as extrusion molding and injection molding, so that it can be used for household goods, various packaging materials, and the like. It can be suitably used for molded articles for a wide range of uses. After use and disposal, it is biodegraded, which is effective in reducing waste and protecting the environment.

 Example

 Hereinafter, specific embodiments of the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to these Examples unless it exceeds the gist thereof. ,.

 [0077] The characteristic values in the following examples were measured by the following methods.

 (1) Number average molecular weight (Mn)

Gels were measured by 'permeation' chromatography (GPC) method. Dissolving the sample into black port Holm, GPC device (Higashisoichi Co., HLC- ⁸ 1 ² 〇 type) was determined by Porisuchi Len translated using the. The column used was TSKgel SuperHM-M (manufactured by Tosoichi Co., Ltd.).

 (2) Flowability: Melt flow ratio (MFR)

190 ^οで with a load of 16 kg.

 (3) Three-point bending stiffness, breaking strength

Injection molded product is conditioned at 23 ° C, 50% relative humidity, 24 hours, and complies with JIS K 7203 Then, the three-point bending rigidity and the breaking strength were measured.

 (4) Appearance of injection molded products

 The injection molded product was visually observed, and the uniformity was evaluated depending on the presence or absence of fiber aggregates.

 (5) Fiber morphology photograph

 In the case of pulp only: A part of a mixture of pretreated pulp or panolep without water and water was freeze-dried and photographed with a scanning electron microscope.

 In the composition: Dissolve the composition in black-mouthed form, add distilled water to extract the pulp or fiber into the aqueous layer side, freeze-dry part of the extract, and use a scanning electron microscope. I took a picture.

 [0078] As the aliphatic polyester (A), the aliphatic polyester (A) produced in Production Example 1 below was used.

 Production Example 1: Production of aliphatic polyester (A)

In a 300 ml reaction vessel equipped with a stirrer, nitrogen inlet tube, heating device, thermometer, and auxiliary agent addition port, succinic acid (b) 118 · lg, 1,4-butanediol (a) 99 · lg, 6.3 g (6.3 mol per 100 mol of succinic acid) of a 90% aqueous lactic acid (c) solution in which 1% by weight of germanium oxide was previously dissolved, and 0.2 g of malic acid (d) (100 mol of conodic acid) 0.15 mol) was added to the mixture, and the mixture was reacted in a nitrogen atmosphere at 180 ° C for 0.5 hours, and then heated to 220 ° C and reacted for 0.5 hours. Subsequently, a polymerization reaction was performed under a reduced pressure of 0.07 × 10 ³ Pa for 2.5 hours. The obtained polyester was milky white, had a number average molecular weight Mn of 75,300 and a melting point of 110 ° C. The lactic acid introduction rate by 1 H-NMR was 6.3 mol per 100 mol of succinic acid.

 [0080] The following were used as the polylactic acid (B) and the pulp, and water was used as the cellulose amorphous region swelling agent (D).

[0081] [Polylactic acid (B)]

 Product name “Lattati # 5400” (manufactured by Shimadzu Corporation) (number average molecular weight Mn: 88000, MFR: 4.5 g / l0min., Melting point 173 ° C)

[0082] Re. Rup]

Pre-treated pulp (C): Kraft pulp treated with refiner (water retention = 280 %, The fiber morphology photograph is as shown in FIG. 2a, and it can be seen that the outer layers of the primary wall and the secondary wall are damaged. )

 Pulp without pre-treatment: Kraft pulp without refiner treatment (water retention rate = 100%, fiber morphology is as shown in Fig. 2b, showing no damage on the surface.)

 Examples 1 and 2

 Aliphatic polyester (A), polylactic acid (B), pulp, and water as a swelling agent for the amorphous region of cellulose were kneaded with the composition shown in Table 1 using a twin-screw extruder. The specifications of the twin-screw extruder used are as follows.

[Twin Screw Extruder]

 Nippon Steel Works Co., Ltd. twin screw extruder `` TEX30 ''

 Screw diameter = 30mm

 Screw length / screw diameter i = 42

 Screw engagement = Complete engagement type

 Screw speed = lOOrpm

 Processing capacity = 5 kg / hr as final yarn amount

[0085] First, the particles of the aliphatic polyester (A) and the polylactic acid (B) were blended and supplied to a twin-screw extruder by a weight feeder. In the twin-screw extruder, three steps, a melting step, a melting 'fibrillation' dispersion step, and a water separation / extrusion step, were set in the extrusion direction according to the screw configuration. The set temperatures for each step are as follows.

 Melting process = 180 ° C

 Melting, defibration, dispersion process = 150 ° C

 Water separationExtrusion process = 150 ° C

[0086] Pulp is preliminarily mixed with water as a cellulose amorphous region swelling agent at a predetermined ratio to form a mixture, and this mixture is mixed by a high-pressure pump at the boundary between the melting step and the melting, defibration, and dispersion steps. It was injected into a twin screw extruder.

[0087] The melting / fibrillation 'dispersion step' was a 1.5MPa pressurized section by a screw configuration, and the water separation 'extrusion step pressure was 53.2kPa by a vacuum pump. [0088] The obtained composition was injection-molded with an injection molding machine having the following specifications, and the obtained molded product was evaluated. The results are shown in Table 1.

[0089] Fig. 3a shows a photograph of the morphology of the fiber in the composition obtained in Example 2.

[0090] [Injection molding machine]

 Injection molding machine manufactured by Toshiba Machine Co., Ltd. [55]

 Form clamping pressure = 55t

 Die = ASTM

 Mold temperature = 40 ° C

 Barrel temperature setting = 170 ° C

 Injection ・ Packing time = 10 seconds

[0091] Examples 3 and 4

 An aliphatic polyester composition was obtained in the same manner as in Example 1, except that the polylactic acid (B) was not used and the composition shown in Table 1 was used, and injection molding was performed in the same manner. Are shown in Table 1.

[0092] Comparative Example 1

 An aliphatic polyester composition was obtained in the same manner as in Example 1 except that pulp and water were not used, and injection molding was performed in the same manner. The evaluation results of the injection-molded product were shown in Table 1.

 [0093] Comparative Example 2

 An aliphatic polyester composition was obtained in the same manner as in Example 2 except that panolep without pretreatment was used instead of the pretreated pulp (C), and injection molding was performed in the same manner. It is shown in Table 1.

 [0094] Fig. 3b shows a morphological photograph of the fibers in the composition obtained in Comparative Example 2.

 [0095] Comparative Example 3

 An aliphatic polyester composition was obtained in the same manner as in Example 3 except that water was not used and water was not separated in a twin-screw extruder, and injection molding was performed in the same manner to evaluate an injection molded product. The results are shown in Table 1.

[0096] Comparative Example 4 In Comparative Example 3, an aliphatic polyester composition was obtained in the same manner except that the pretreated pulp (C) was not used, and injection molding was performed in the same manner. The evaluation results of the injection molded product are shown in Table 1.

[table 1]

図 2a, 2b、図 3a, 3b、及び表 1より次のことが明らかである。即ち、前処理を行って 一次壁及び二次壁外層を傷付けたパルプを用いた実施例 2の組成物では、パルプ がミクロフイブリル状に均一に微細分散しているのに対して、前処理無しパルプを用 いた比較例 2の組成物ではパルプが解繊されずに、ちぎれた状態で散在している。 そして、パルプがミクロフイブリル状に均一に微細分散した組成物であれば、高剛性 で高強度のファイバー Z生分解性樹脂複合成形品を得ることができる。

The following is clear from FIGS. 2a and 2b, FIGS. 3a and 3b, and Table 1. That is, in the composition of Example 2 using pulp in which pretreatment was performed and the outer layers of the primary wall and the secondary wall were damaged, the pulp was uniformly finely dispersed in the form of microfibrils, whereas In the composition of Comparative Example 2 using no pulp, the pulp was not defibrated, but was scattered in a torn state. If the pulp is a composition in which the pulp is uniformly finely dispersed in the form of microfibrils, a high rigidity and high strength fiber Z biodegradable resin composite molded article can be obtained.

Claims

The scope of the claims  [I] Pulp with damaged primary and secondary wall outer layers.  [2] In claim 1, the outer layers of the primary wall and the secondary wall are subjected to a refiner treatment and a medium stirring mill treatment. Pulp that has been damaged by milling, milling, or milling. [3] The pulp according to claim 1, having a water retention of 150 to 600%. [4] The pulp according to claim 1, having a water retention of 200 to 400%. [5] Cellulosic fibers obtained by damaging the outer layers of the primary wall and the secondary wall.  [6] In claim 5, the outer layers of the primary wall and the secondary wall are subjected to a refiner treatment and a medium stirring mill treatment. Cellulosic fibers that have been damaged by vibration milling or milling. [7] The cellulosic fiber according to claim 5, having a water retention of 150 to 600%. [8] The cellulosic fiber according to claim 5, which has a water retention of 200 to 400%. [9] A method for microfibrillating pulp, which comprises kneading pulp formed by damaging the outer layers of primary and secondary walls in the presence of a cellulose amorphous region swelling agent to fibrillate fiber components.  [10] Cellulosic fibers characterized by fibrillating fiber components by kneading cellulosic fibers formed by damaging the outer layers of the primary and secondary walls in the presence of a swelling agent for the amorphous cellulose region. A method for microfibrillating fibers.  [II] (11) 99.9 parts by weight of a resin component comprising an aliphatic polyester (A) obtained by reacting (a) an aliphatic diol with (b) an aliphatic dicarboxylic acid and / or a derivative thereof; Fiber component consisting of pretreated pulp and / or cellulosic fiber (C) having damaged primary and secondary wall outer layers 99-0.1 parts by weight (However, the total amount of resin component and fiber component is 100 parts by weight .)When  Is subjected to a melt-kneading process in the presence of a cellulose amorphous region swelling agent (D). [12] (a) an aliphatic polyester obtained by reacting (a) an aliphatic diol with (b) an aliphatic dicarboxylic acid and / or a derivative thereof (A) 1% by weight or more, and polylactic acid (B) 99% by weight % Or less resin component 11-99.9 parts by weight Pre-treated pulp and / or cellulosic fibers that damage the outer layers of the primary and secondary walls ( 99-1 0.1 parts by weight of the fiber component consisting of C) (however, the total of the resin component and the fiber component is 100 parts by weight)  Is subjected to a melt-kneading process in the presence of a cellulose amorphous region swelling agent (D). 13. The process for producing an aliphatic polyester composition according to claim 11, wherein the pretreated pulp and / or the cellulosic fiber (C) is further chemically modified.  [14] The method according to claim 11 or 12, wherein the aliphatic polyester (A) comprises (a) an aliphatic diol,  (b) an aliphatic polyester composition characterized by being obtained by reacting an aliphatic dicarboxylic acid and / or a derivative thereof with (c) a bifunctional aliphatic hydroxycanoleic acid and / or a derivative thereof. Production method.  15. The melt kneading process according to claim 11 or 12, wherein the resin component, the fiber component, and the cellulose amorphous region swelling agent are supplied to a twin-screw extruder, and the cell opening is mixed in the twin-screw extruder. The fiber component is defibrated and dispersed in the resin component in the presence of the amorphous region swelling agent. The defibration 'dispersion step, and then the resin component is melted and the fiber component is further defibrated and finely dispersed. A process for separating the cellulose amorphous region swelling agent and extruding a kneaded product by separating the cellulose amorphous region swelling agent and extruding the kneaded product. .  [16] The melt-kneading process according to claim 11 or 12, wherein the melt-kneading process supplies the resin component to a twin-screw extruder and melts the resin component in the twin-screw extruder; And a cellulose amorphous swelling agent is injected under pressure into the twin-screw extruder, and the fiber component is defibrated and finely dispersed in the resin component in the presence of the cell opening amorphous region swelling agent. Production of an aliphatic polyester composition characterized by comprising a 'fibrillation' dispersing step, followed by separating the cellulose amorphous region swelling agent and extruding the kneaded material while separating and extruding the cellulose amorphous region swelling agent. Method. 17. The method for producing an aliphatic polyester composition according to claim 11, wherein the water retention of the pretreated pulp and / or the cellulosic fiber (C) is 150 to 600%. [18] The method for producing an aliphatic polyester composition according to claim 11 or 12, wherein (a) the aliphatic diol is represented by the following general formula (I).  HO-R'-OH · '· (Ι) (In the general formula (I), R ¹ is an aliphatic hydrocarbon group having 211 carbon atoms.) [19] Claim 18, wherein (a) aliphatic diol power ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4 A method for producing an aliphatic polyester composition, wherein the composition is at least one member selected from the group consisting of cyclohexanediol and 1,6-cyclohexanedimethanol.  [20] The method for producing an aliphatic polyester composition according to claim 19, wherein (a) the aliphatic diol is 1,4-butanediol. [21] The method according to claim 11 or 12, wherein (b) the aliphatic dicarboxylic acid and / or a derivative thereof is represented by the following general formula (Π), their lower alkyl esters having 14 to 14 carbon atoms, and A method for producing an aliphatic polyester composition, which is one or more selected from the group consisting of anhydrides thereof. HOOC—R ² — COOH · · · (II) (In the general formula (II), R ² is a direct bond or a divalent aliphatic hydrocarbon group having 2 to 11 carbon atoms.)  [22] In claim 21, (b) the aliphatic dicarboxylic acid power of the aliphatic dicarboxylic acid and / or a derivative thereof from oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, suberic acid, and dodecane diacid A method for producing an aliphatic polyester composition, wherein the composition is at least one member selected from the group consisting of:  [23] The method according to claim 22, wherein (b) aliphatic dicarboxylic acid and Z or a derivative thereof are succinic acid and / or succinic anhydride, or a mixture of succinic acid and / or succinic anhydride and adipic acid. A method for producing a characteristic aliphatic polyester composition. [24] In claim 14, (c) the bifunctional aliphatic hydroxycarboxylic acid of the bifunctional aliphatic hydroxycarboxylic acid and / or a derivative thereof corresponds to an aliphatic hydroxycarboxylic acid unit represented by the following general formula (II). An aliphatic hydroxycarboxylic acid, the derivative of which is A process for producing an aliphatic polyester composition, which is a lower alkyl ester of loxycarboxylic acid having 14 to 14 carbon atoms or an intramolecular ester thereof. HO-R ³ -COOH (In the general formula (ΠΙ), R ³ is a divalent aliphatic hydrocarbon group having 11 to 11 carbon atoms.) In claim 24, (c) a bifunctional aliphatic hydroxycarboxylic acid and / or a derivative thereof is A method for producing an aliphatic polyester composition represented by the following general formula (IV).  [Chemical 1] H0-CH-COOH  I… (! V) ^ a ⁿ 2a + 1 (In the general formula (IV), a is 0 or an integer of 1 or more.)  [26] The method according to claim 25, wherein the bifunctional aliphatic hydroxycarboxylic acid is lactic acid, glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxyn-butyric acid, 2-hydroxy-3,3-dimethylbutyric acid. One or two selected from the group consisting of, 2-hydroxy-3-methylbutyric acid, 2-methyllactic acid, 2-hydroxycaproic acid, and ring-opened ratatatones  [27] The method for producing an aliphatic polyester composition according to claim 26, wherein the bifunctional aliphatic hydroxycarboxylic acid is lactic acid. [28] The method according to claim 11 or 12, wherein (a) an aliphatic diol and (b) an aliphatic dicarboxylic acid and / or a derivative thereof are produced under a polyester-forming condition in the presence of a catalyst comprising a germanium compound. For producing an aliphatic polyester composition, characterized by reacting [29] The aliphatic polyester according to claim 11 or 12, wherein (a) an aliphatic diol is used in an amount of 1 to 50 mol per 100 mol of (b) an aliphatic dicarboxylic acid and / or a derivative thereof. A method for producing the composition. [30] The method according to claim 14, wherein (c) a bifunctional aliphatic hydroxycarboxylic acid and / or a derivative thereof is added to (b) an aliphatic dicarboxylic acid and / or Z or a derivative thereof in an amount of 0.0460 A method for producing an aliphatic polyester composition, which is used. [31] In claim 14, the aliphatic polyester (A) is an aliphatic polyester copolymer mainly composed of (a) an aliphatic diol and (b) an aliphatic dicarboxylic acid and / or a derivative thereof. A method for producing an aliphatic polyester composition, comprising (c) 0.02 to 30 mol of a bifunctional aliphatic hydroxycarboxylic acid unit based on 100 mol of all constituent components. [32] The number average molecular weight of the aliphatic polyester (A) is 10,000 or more according to claim 11 or 12, A method for producing an aliphatic polyester composition, wherein the composition is 300,000 or less. [33] The method for producing an aliphatic polyester composition according to claim 11 or 12, wherein the polylactic acid (B) has a number average molecular weight of 30,000 or more and 1,000,000 or less. [34] The method for producing an aliphatic polyester composition according to claim 11 or 12, wherein the polylactic acid (B) contains at least 95 mol% of an L-isomer. [35] The method according to claim 11 or 12, wherein the cellulose amorphous region swelling agent (D) is at least one member selected from the group consisting of water, ethylenedialcol, butylene glycol, methyl alcohol, and ethyl alcohol. A method for producing an aliphatic polyester composition, comprising:  [36] The process for producing an aliphatic polyester composition according to claim 11 or 12, wherein the resin component comprises 100 to 40% by weight of the aliphatic polyester (A) and 0 to 60% by weight of the polylactic acid (B). Method.  37. The process for producing an aliphatic polyester composition according to claim 11, wherein 95 to 3 parts by weight of the fiber component is used with respect to 5 to 97 parts by weight of the resin component.  38. The aliphatic polyester composition according to claim 11, wherein the cellulose amorphous region swelling agent (D) is used in an amount of 100 to 600% by weight of the pretreated pulp and / or the cellulosic fiber (C). Manufacturing method. 39. The method according to claim 15, wherein the temperature in the defibrating and dispersing steps is 30 to 90 ° C., the temperature in the melting and dispersing step is 120 to 200 ° C., and the subsequent step of separating and extruding the cellulose amorphous region swelling agent The temperature of 120-200. C. The method for producing an aliphatic polyester composition, wherein the screw speed is in the range of 50-400 rpm in all steps, and the screw length / screw diameter ratio is 25-50. 17. The method according to claim 16, wherein the temperature of the melting step is 120-200 ° C., the temperature of the melting 'fibrillation' dispersing step is 120-180 ° C., and the subsequent cellulose amorphous region swelling agent separation / extrusion step. Temperature is 120-200 ° C, pressure is at atmospheric pressure-vacuum, screw rotation speed is in the range of 50-400rpm in all cases. The mixture of the agent (D) and the fiber component is injected under pressure into the molten resin component at a pressure of at least 1 MPa using the pump, without separating the cellulose amorphous region swelling agent (D). A method for producing an aliphatic polyester composition, wherein the composition is further melted, defibrated, and finely dispersed, and has a screw length Z screw diameter ratio of 3070.