JP3474063B2 - Biodegradable resin composition - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a biodegradable polyester composition which is excellent in flexibility and biodegradability and can be suitably used in a wide range of applications such as films, containers and fibers.

[0002]

2. Description of the Related Art In recent years, biodegradable polymers which can be decomposed by microorganisms have attracted attention as social demands for environmental protection have increased. Specific examples of the biodegradable polymer include melt-moldable aliphatic polyesters such as polyhydroxybutyrate, polycaprolactone, polylactic acid, and polybutylene succinate.

However, microbial-producible biodegradable polymers such as polyhydroxybutyrate are extremely expensive and are obtained using chemical synthesis techniques such as polycaprolactone, polylactic acid, polybutylene succinate and the like. Compared to general-purpose resins such as olefin resins, the cost of biodegradable polymers is still 2-3 times higher, and these cost problems hinder the versatility of biodegradable polymers. Is.

In order to address the above problems, a biodegradable polymer is blended with an inexpensive organic extender (for example, starches) or an inorganic extender (for example, an inorganic filler such as talc or calcium carbonate). Various attempts have been made to reduce the cost of biodegradable polymers.

For example, JP-A-5-32822 discloses that "a polysaccharide such as starch is contained in an amount of 90 to 10% by weight and a modified ethylene-vinyl alcohol copolymer having an ionic group at its end is included in an amount of 10 to 90% by weight. "Disintegrating resin composition" has been proposed, and in JP-A-4-353537, a composition having "ethylene content of 20 to 60 mol% and saponification degree of vinyl acetate unit of 90 mol% or less and Melting point is 1
Biodegradable resin composition comprising a partially saponified ethylene-vinyl acetate copolymer having a temperature of 50 ° C. or lower and a starch-based polymer ”
In addition, in JP-A-4-248851, "aliphatic polyester resin 20 to 80% by weight is proposed.
And a biodegradable composition comprising 80 to 20% by weight of vegetable protein and / or starch.

However, the biodegradable composition according to the above series of proposals has poor compatibility between the ethylene-vinyl acetate resin or the aliphatic polyester resin used as the binder resin and the starch, so that the moldability and physical properties, especially There is a problem that it is inferior in flexibility and lacks in practicality.

Further, in Japanese Patent Laid-Open No. 7-102114,
"A biodegradable composition comprising cellulose ester, starch and a plasticizer, wherein the content of the plasticizer in the biodegradable composition is 30 to 70% by weight, and the weight ratio of the cellulose ester and the starch is A biodegradable composition characterized by being 99: 1 to 20:80 has been proposed.

However, the biodegradable composition according to the above-mentioned proposal has a good compatibility with the cellulose ester used as the binder resin and the starch, but contains a large amount of the plasticizer, so that the rigidity is poor. In addition, when used for a film or a container, there is a concern that the plasticizer may be eluted (breathing), which limits the practical use.

Further, JP-A-7-70367 discloses, "Biodegradation containing at least one thermoplastic starch and at least one thermoplastic aliphatic polyester, characterized in that it contains at least one hydroxycarboxylic acid salt. Molding compositions "have been proposed.

However, since the biodegradable composition according to the above-mentioned proposal uses thermoplastic starch, that is, gelatinized starch, the physical properties are deteriorated due to hydrolysis of the aliphatic polyester at the time of molding and the molded article is heated. It is not practical because it may deteriorate.

As described above, while having excellent flexibility, rigidity, biodegradability, etc., it is relatively inexpensive and can be used for films, containers,
A biodegradable composition suitable for a wide range of applications such as fibers has not been put into practical use.

[0012]

In order to solve the above-mentioned conventional problems, the present invention has excellent flexibility and biodegradability, and is relatively inexpensive and suitable for a wide range of uses. It is an object to provide a polyester composition.

[0013]

The biodegradable polyester composition according to the invention of claim 1 (hereinafter referred to as "first invention") is based on 100 parts by weight of the following component (a):
10 to 260 parts by weight of the component (b) and 0.5 to the component (c).
It is characterized in that 10 parts by weight are mixed and reacted. Component (a): Melt viscosity at 200 ° C. is 1000 to 1
Aliphatic polyester (b) component of 50,000 poise: biodegradable organic fine particles (c) component: polyfunctional isocyanate compound

Specific examples of the above linear aliphatic polyester are not particularly limited, but polyethylene adipate, polypropylene adipate, polybutylene adipate obtained by condensation polymerization of polyhydric alcohol and aliphatic dicarboxylic acid. Examples thereof include polyhexyl adipate, polybutylene succinate, polybutylene succinate adipate, and polycaprolactone obtained by ring-opening polymerization of caprolactone, and one or more of these are preferably used.

Specific examples of the above-mentioned side chain aliphatic polyester are not particularly limited, but polylactic acid, poly-3-hydroxybutyrate, poly-3-hydroxyvalerate, poly-3-hydroxycarboxylate. Proate, poly-3-hydroxyheptanoate, poly-3-hydroxyoctanoate, poly-3-hydroxynanoate,
Examples include poly-3-hydroxydecanoate, poly-3-hydroxydodecanoate, poly-3-methyl-5-hydroxyvaleresalate, poly-3,3′-dimethylpropylene adipate, and the like. Or 2
Among them, one or more kinds are preferably used, and among them, one having an alkyl group having 1 to 9 carbon atoms as a substituent is excellent in biodegradability, and thus is more preferably used.

The aliphatic polyester as the component (a) means a straight-chain aliphatic polyester or a side-chain aliphatic polyester synthesized by using only a monomer having no aromatic ring, and its chemical structure is It is not particularly limited.

The method for synthesizing the aliphatic polyester is not particularly limited, but examples thereof include condensation polymerization of polyhydric alcohol and aliphatic dicarboxylic acid, polymerization of hydroxy group-containing carboxylic acid, and ring-opening polymerization of caprolactone. ,
Conventionally known methods such as production by a microorganism can be mentioned, and any of these methods is suitably adopted.

Specific examples of the polyhydric alcohol are not particularly limited, but ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, butylene glycol, polybutylene glycol, butanediol 1 , 4, hexanediol 1, 6 and the like. Specific examples of the aliphatic dicarboxylic acid include, but are not particularly limited to, adipic acid, succinic acid, and succinic anhydride.

In the first invention, the melt viscosity of the above aliphatic polyester at 200 ° C. is 1000 to 1500.
It must be 00 poise. The melt viscosity referred to here is the melt viscosity measured by the following method. [Melt Viscosity Measuring Method] Measuring device: parallel disk rheometer RMS (manufactured by Toyo Seiki Co., Ltd.) Measuring conditions: temperature 200 ° C., strain 20%, frequency 1 ra
d / sec

When the melt viscosity of the above aliphatic polyester at 200 ° C. is less than 1000 poise, the mechanical strength of the resulting biodegradable polyester composition becomes insufficient, and conversely, when it exceeds 150000 poise, the resulting biodegradation is obtained. The fluidity of the water-soluble polyester composition at the time of heating and melting is poor, and the molding workability is reduced.

The biodegradable organic fine particles of the component (b) are not particularly limited, but include starches, wood flour, cellulose, chitin, chitosan, collagen, keratin, fibroin, and the like. One or more of the above are preferably used, and among them, starches having a high biodegradation rate are more preferably used.

The particle size of the biodegradable organic fine particles is not particularly limited, but is preferably 50 μm or less. When the particle size of the biodegradable organic fine particles exceeds 50 μm, the mechanical strength of the molded product finally obtained from the biodegradable polyester composition may be insufficient.

Specific examples of the polyfunctional isocyanate compound as the component (c) are not particularly limited, but hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 3-isocyanate methyl-3, 5,5-Trimethylcyclohexyl isocyanate, dicyclohexylmethane-4,4 '
An aliphatic diisocyanate such as diisocyanate,
2,4-Tolylene diisocyanate, 2,6-Tolylene diisocyanate, Mixed isocyanate of 2,4-Tolylene diisocyanate and 2,6-Tolylene diisocyanate, 4,4'-Diphenylmethane diisocyanate, Hydrogenated diphenylmethane diisocyanate, Diphenyl Aromatic diisocyanates such as methylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, and isophorone diisocyanate, adducts of trimethylol propane and toluylene diisocyanate, trimethylol propane and 1, Examples include triisocyanates such as adducts with 6-hexamethylene diisocyanate, and one or more of these are preferably used. Among them, one of the diisocyanates
More preferably, one kind or two or more kinds is used.

Among the above polyfunctional isocyanate compounds, when importance is placed on improving the flexibility of the biodegradable polyester composition, diphenylmethane diisocyanate having a structure in which an electron-withdrawing aromatic ring is adjacent to an isocyanate group is used. Aromatic diisocyanates are more preferably used, and when importance is placed on improving the biodegradability of the biodegradable polyester composition, an aliphatic diisocyanate such as hexamethylene diisocyanate containing no aromatic ring in the molecular chain is used. Classes are more preferably used.

In the biodegradable polyester composition of the first invention, the aliphatic polyester 100 as the component (a) is used.
10 to 260 parts by weight, preferably 50 to 150 parts by weight, of the above-mentioned component (b) biodegradable organic fine particles, based on parts by weight,
It is also necessary to mix 0.5 to 10 parts by weight, preferably 3 to 6 parts by weight of the polyfunctional isocyanate compound of the above-mentioned component (c), and to react them.

If the amount of the biodegradable organic fine particles of the component (b) added is less than 10 parts by weight relative to 100 parts by weight of the aliphatic polyester of the component (a), a sufficient cost reduction effect cannot be obtained, and the reverse If it exceeds 260 parts by weight, the flexibility of the molded product finally obtained from the biodegradable polyester composition becomes poor.

Further, the aliphatic polyester 10 as the component (a)
When the amount of the polyfunctional isocyanate compound as the component (c) added to 0 part by weight is less than 0.5 part by weight, the effect of improving the flexibility due to chain extension of the aliphatic polyester cannot be sufficiently obtained, and conversely 10 parts by weight. When it exceeds, the excess isocyanate group causes intermolecular cross-linking to increase the gel fraction, and the flexibility of the biodegradable polyester composition becomes poor.

The invention according to claim 2 (hereinafter referred to as "second invention")
Say. The biodegradable polyester composition according to (1) contains 1 to 70 parts by weight of component (e) per 100 parts by weight of component (d) below.
10 parts by weight, and the total amount of component (d) and component (e) is 10
10 to 260 parts by weight of the component (f) with respect to 0 parts by weight,
Component (g) is mixed so as to be 0.5 to 25 parts by weight,
It is characterized by being reacted. Component (d): Melt viscosity at 200 ° C. is 1000 to 1
Aliphatic polyester (e) component having 50,000 poises: Aliphatic polyester (f) component having number average molecular weight of 500 to 5000: Biodegradable organic fine particles (g) component: Polyfunctional isocyanate compound

The second invention is obtained by using a high molecular weight component (d) defined by the melt viscosity in the above range and a low molecular weight component (e) defined by the number average molecular weight in the above range in combination. It further imparts further excellent flexibility to the biodegradable resin composition.

Examples of the aliphatic polyester as the component (d) include the same as the component (a) of the first invention.

The aliphatic polyester as the component (e) is the same as the component (d) except that the number average molecular weight is 500 to 5,000. The number average molecular weight referred to here is the number average molecular weight measured by the following method. [Number average molecular weight measuring method] Measuring apparatus: Showa Denko column "shodex K-8"
02, K-803, K-804 "measurement conditions: mobile phase chloroform, flow rate 1 ml / min.

When the number average molecular weight of the aliphatic polyester as the component (e) is less than 500, the mechanical strength of the resulting biodegradable resin composition becomes insufficient, and conversely 500.
When it exceeds 0, the elastic modulus of the obtained biodegradable resin composition becomes high, and the flexibility of the finally obtained molded article decreases.

Further, as the component (e), it is preferable to use an oligomer of caprolactone. The above-mentioned oligomer of caprolactone means polycaprolactone having a number average molecular weight of 500 to 5000 obtained by ring-opening polymerization of caprolactone. By using the caprolactone oligomer as the component (e), a biodegradable resin composition having both low elastic modulus and high flexibility can be obtained.

The biodegradable organic fine particles of the component (f) are the same as those of the component (b) of the first invention, and the polyfunctional isocyanate compound of the component (g) is () of the first invention. The same as the component c) can be mentioned.

In the biodegradable polyester composition of the second invention, (e) is added to 100 parts by weight of the above-mentioned component (d).
The amount of the component is 1 to 70 parts by weight, and the amount of the component (f) is 10 to 26 with respect to 100 parts by weight of the total amount of the components (d) and (e).
It is necessary to mix and react so that 0 parts by weight, more preferably 3 to 15 parts by weight, the component (g) is 0.5 to 25 parts by weight, more preferably 3 to 15 parts by weight. .

In the biodegradable resin composition according to the second aspect of the invention, when the content of the component (e) is less than 1 part by weight per 100 parts by weight of the component (d), the elastic modulus of the resulting biodegradable resin composition. And the flexibility of the finally obtained molded product is lowered, and conversely, when it exceeds 70 parts by weight, the residual amount of the component (e) which is not chain-extended increases, and the finally obtained molded product is increased. The breaking elongation of No. 1 is not sufficiently improved and the component (e) tends to bleed out on the surface of the molded product, which makes it difficult to obtain a good molded product.

It is sufficient that the amount of the biodegradable organic fine particles of the component (f) is less than 10 parts by weight based on 100 parts by weight of the total amount of the aliphatic polyesters of the components (d) and (e). If the cost reduction effect cannot be obtained and conversely it exceeds 260 parts by weight, the flexibility of the molded product finally obtained from the biodegradable polyester composition becomes poor.

When the addition amount of the polyfunctional isocyanate compound of the component (g) is less than 0.5 parts by weight based on 100 parts by weight of the total amount of the aliphatic polyesters of the components (d) and (e), the aliphatic polyester is If the effect of improving flexibility due to chain extension is not sufficiently obtained and conversely exceeds 25 parts by weight, excess isocyanate groups cause intermolecular cross-linking, leading to an increase in gel fraction, resulting in a biodegradable polyester composition. Becomes less flexible. Further, as the amount of the polyfunctional isocyanate compound as the component (g) increases, the chain extension reaction of the aliphatic polyester is promoted and the molecular weight increases. Therefore, when 10 parts by weight or more of the component (g) is used, the fat of the component (d) It is preferable to use a group polyester having a melt viscosity of 100,000 or less.

The method for producing the biodegradable polyester composition according to the first and second aspects of the invention is not special and a predetermined amount of each of the aliphatic polyester, the biodegradable organic fine particles and the polyfunctional isocyanate compound is uniaxially extruded. Machine, twin-screw extruder, Banbury mixer, kneading roll, brabender,
Using a known mixing device such as a plastograph or a kneader, at a temperature of about 100 to 300 ° C. for about 3 to 15 minutes,
It may be mixed by a conventional method.

In the above production, the polyfunctional isocyanate compound (c) component or (g) component is mixed in advance with the (a) component and the (b) component, or the (d) component and the (e) component and the (f) component. After that, they may be added, or they may be mixed at the same time.

Further, in the above-mentioned biodegradable polyester composition according to the first invention and the second invention, by using starches as the biodegradable organic fine particles, more excellent biodegradability and flexibility can be obtained. Can be done.

Specific examples of the above-mentioned starches include, but are not limited to, corn, wheat, potatoes,
Raw starch obtained from rice, tapioca, sweet potato, etc., physically modified starch such as α starch, oxidized starch, esterified starch,
Examples include chemically modified starch such as etherified starch and cross-linked starch, and enzyme-modified starch such as dextrin and amylose, and one or more of these are preferably used. The shape of the starches is not particularly limited, and may be tuber-like or granular.

The above-mentioned starches are added at 80 ° C. in order to prevent hydrolysis during mixing with the aliphatic polyester.
It is preferable to use a pre-dried product under the condition of about 2 hours.

In the biodegradable polyester composition according to the second aspect of the present invention, as the amount of the starches added increases in the range of 10 to 260 parts by weight with respect to 100 parts by weight of the aliphatic polyester, the resulting biodegradable polyester composition is obtained. Increases the rate of biodegradation of the product.

The biodegradable polyester composition according to the first invention and the second invention may be added with various additives such as a filler, a coloring agent, a reinforcing agent, and waxes, if necessary, within a range not hindering the achievement of the object of the present invention. One or two or more of the agents may be contained.

Specific examples of the extender include, but are not limited to, talc, calcium carbonate, magnesium carbonate, barium carbonate, magnesium hydroxide, aluminum hydroxide, magnesium oxide, aluminum oxide, diatomaceous earth, and feldspar powder. , Mica, clay, silica, alumina, glass powder, stainless steel, aluminum, copper, inorganic powder such as magnetite and wood powder, cellulose, chitin, chitosan,
Organic powders such as collagen, keratin, fibroin, etc. may be mentioned, and one kind or two or more kinds thereof are preferably used.

The biodegradable polyester composition according to the first invention and the second invention can be used in an unstretched state after molding, or in a state where post-processing such as uniaxial stretching or biaxial stretching is performed. Of course, it can be used.

[0048]

The biodegradable polyester composition according to the first invention comprises an aliphatic polyester 100 having a specific melt viscosity.
With respect to parts by weight, a specific amount of biodegradable organic fine particles are mixed, and since the aliphatic polyester is chain-extended with a specific amount of polyfunctional isocyanate compound, excellent flexibility and biodegradability are obtained. And is relatively inexpensive.

In the biodegradable resin composition according to the second invention, a specific amount of the aliphatic polyester having a specific number average molecular weight is mixed with a specific amount of the aliphatic polyester having a specific melt viscosity, and Since a specific amount of the polyfunctional isocyanate compound is mixed with the total specific amount of the aliphatic polyester and the aliphatic polyester is chain-extended and / or co-chain-extended, excellent flexibility and biodegradability are exhibited. To do.

In the biodegradable resin composition according to the second aspect of the present invention, by using an oligomer of caprolactone as the aliphatic polyester having a specific number average molecular weight, more excellent flexibility and biodegradability are exhibited.

Further, by using starches as the biodegradable organic fine particles, the biodegradability and the flexibility are further enhanced.

[0052]

BEST MODE FOR CARRYING OUT THE INVENTION The following examples are given to explain the present invention in more detail, but the present invention is not limited to these examples. In the examples, "part" means "part by weight", "melt viscosity" means "melt viscosity at 200 ° C", and "molecular weight" means "number average molecular weight".

(Example 1) (1) Production of biodegradable polyester composition In Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.), polycaprolactone having a melt viscosity of 5000 poise (a) as component (a) (trade name "Placcel H7 ", manufactured by Daicel Chemical Industries, Ltd.) and 50 parts of corn starch starch (average particle size 30 μm) as the component (b) were added and mixed at 180 ° C. for 4 minutes, and then 4,4′- as the component (c). 6 parts of diphenylmethane diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added and mixed at 180 ° C. for 10 minutes to obtain a biodegradable polyester composition.

(2) Preparation of molded product The biodegradable polyester composition obtained above was molded into a sheet having a thickness of 0.4 mm using a hydraulic press machine (manufactured by Toyo Seiki Co., Ltd.), and an unstretched sheet. A shaped body was obtained.

(3) Evaluation The performance (elongation and biodegradability) of the molded article obtained above was evaluated by the following method. The results are shown in Table 1. The evaluation is 23 ° C.-65 unless otherwise specified.
The measurement was performed in a room with constant temperature and humidity of% RH.

Elongated sheet-shaped compacts (0.4 mm thick) were punched out with a No. 1 dumbbell to prepare measurement samples. Then, Tensilon (O
(Made by RIENTEC), using a pulling speed of 200 mm /
The resulting sample was subjected to a tensile test in minutes to determine the elongation (%).

A biodegradable sheet-like compact (0.
(4 mm thickness) in liquid nitrogen and cooled to the glass transition temperature of the molded body or lower, and then crushed with several pieces of dry ice in a personal mill SCM-40A crusher (manufactured by SIBATA) to obtain an average particle size of 0. A measurement powder of 0.8 mm was prepared.

According to JIS K-6950 "Plastics-Test method for aerobic biodegradability by activated sludge", Coulometer OM3001A type (manufactured by Okura Electric Co., Ltd.) as a biodegradability evaluation device and activated sludge A as activated sludge were used. hand,
The biodegradability test of the obtained powder was carried out, and by the following formula, 28
The degree of biodegradation (%) after day was determined. DB = [(SB) / ThOD] × 100 DB: degree of biodegradation of plastic or control substance after 28 days (%) S: BOD value of culture solution for biological test or control substance after 28 days (mg) ) B: BOD value (mg) of culture medium for biological empty test ThOD: Calculated value of oxygen consumption required to completely oxidize a plastic or a control substance (theoretical oxygen demand,
mg)

Example 2 In the production of a biodegradable polyester composition, cornstarch starch (average particle size 3
Example 1 except that the addition amount of 0 μm) was 100 parts.
A biodegradable polyester composition was obtained in the same manner as in.

Example 3 In the production of a biodegradable polyester composition, the component (a) has a melt viscosity of 1000.
0 Poise polybutylene succinate adipate (trade name "Bionore # 3010", Showa High Polymer Co., Ltd.)
A biodegradable polyester composition was obtained in the same manner as in Example 1 except that 100 parts was used.

Example 4 In the production of a biodegradable polyester composition, corn starch starch (average particle size 3
Example 3 except that the addition amount of 0 μm) was 100 parts.
A biodegradable polyester composition was obtained in the same manner as in.

Comparative Example 1 In the production of a biodegradable polyester composition, corn starch starch (average particle size 3
Biodegradable polyester composition in the same manner as in Example 1 except that the polyfunctional isocyanate compound (4,4′-diphenylmethane diisocyanate), which is the component (c), was not added. Got

(Comparative Example 2) In the production of a biodegradable polyester composition, corn starch starch (average particle size 3
Biodegradable polyester composition in the same manner as in Example 3 except that the polyfunctional isocyanate compound (4,4′-diphenylmethane diisocyanate), which is the component (c), was not added. Got

Using the five types of biodegradable polyester compositions obtained in Examples 2-4 and Comparative Examples 1-2, Example 1 was used.
5 types of unstretched sheet-shaped molded products (0.4
mm thickness). Then, the performance of the obtained five types of molded products was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0065]

[Table 1]

Example 5 (1) Production of biodegradable polyester composition In Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.), polycaprolactone having a melt viscosity of 5000 poise as a component (d) (trade name “Placcel H7 "(manufactured by Daicel Chemical Industries, Ltd.) and 60 parts of corn starch starch (average particle size 30 μm) as component (f) were added and mixed at 180 ° C. for 4 minutes, and then melt viscosity of component (e) was 200.
After adding 20 parts by weight of polycaprolactone which is 0 poise and mixing at 180 ° C. for 2 minutes, 6 parts of 4,4′-diphenylmethane diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added as a component (g), and the mixture was heated at 180 ° C. The mixture was further mixed for 14 minutes to obtain a biodegradable polyester composition.

Example 6 In the same manner as in Example 5, except that 100 parts of polybutylene succinate having a melt viscosity of 6,400 poise was used as the component (d) in the production of the biodegradable resin composition. A biodegradable resin composition was obtained.

Example 7 In the same manner as in Example 5, except that 100 parts of polybutylene succinate adipate having a melt viscosity of 10,000 poise was used as the component (d) in the production of the biodegradable resin composition. A biodegradable resin composition was obtained.

(Example 8) A biodegradable resin composition was prepared in the same manner as in Example 5 except that the amount of corn starch starch as the component (f) was changed to 120 parts in the production of the biodegradable resin composition. Obtained.

Example 9 A biodegradable resin composition was prepared in the same manner as in Example 6 except that the amount of the corn starch starch as the component (f) was changed to 120 parts in the production of the biodegradable resin composition. Obtained.

Example 10 A biodegradable resin composition was prepared in the same manner as in Example 5 except that the amount of the corn starch starch as the component (f) was changed to 240 parts in the production of the biodegradable resin composition. Obtained.

(Example 11) A biodegradable resin composition was prepared in the same manner as in Example 6 except that the amount of the corn starch starch as the component (f) was changed to 240 parts in the production of the biodegradable resin composition. Obtained.

(Example 12) In the production of a biodegradable resin composition, the amount of (e) component polycaprolactone having a molecular weight of 2000 was 11 parts, and the amount of (f) component corn starch starch was 120 parts. Parts, and a biodegradable resin composition was obtained in the same manner as in Example 5 except that the amount of 4,4′-diphenylmethane diisocyanate as the component (g) was 2.04 parts.

(Example 13) In the production of a biodegradable resin composition, the amount of the component (e) polycaprolactone having a molecular weight of 2000 was 67 parts, and the amount of the component (f) corn starch starch was 120. Parts, and a biodegradable resin composition was obtained in the same manner as in Example 5 except that the amount of 4,4′-diphenylmethane diisocyanate as the component (g) was 6.96 parts.

Example 14 In the production of a biodegradable resin composition, 100 parts of polycaprolactone having a melt viscosity of 100,000 poise as component (d) and 20 parts of polycaprolactone (molecular weight 2000) as component (e) were used. A biodegradable resin composition was obtained in the same manner as in Example 5, except that the amount of 4,4′-diphenylmethane diisocyanate as the component (g) was changed to 2.4 parts.

(Comparative Example 3) In the production of a biodegradable resin composition, 100 parts of polycaprolactone having a melt viscosity of 5,000 poises as the component (d) without containing the components (e) and (g) and A biodegradable resin composition was obtained in the same manner as in Example 8 except that 100 parts of corn starch starch was used as the component (f) and mixed at 180 ° C. for 5 minutes.

Comparative Example 4 In the production of the biodegradable resin composition, 100 parts of polybutylene succinate adipate having a melt viscosity of 10,000 poise and 100 parts of corn starch starch were used as the component (d). A biodegradable resin composition was obtained in the same manner as in Comparative Example 3 except for the above.

Comparative Example 5 A biodegradable resin composition was prepared in the same manner as in Comparative Example 3 except that the amount of the cornstarch starch as the component (f) was 200 parts in the production of the biodegradable resin composition. Obtained.

Comparative Example 6 A biodegradable resin composition was prepared in the same manner as in Comparative Example 4 except that the amount of the corn starch starch as the component (f) was 200 parts in the production of the biodegradable resin composition. Obtained.

Comparative Example 7 A biodegradable resin composition was prepared in the same manner as in Example 8 except that the amount of cornstarch starch as the component (f) was 360 parts in the production of the biodegradable resin composition. Obtained.

(Comparative Example 8) In the same manner as in Example 8, except that the amount of 4,4'-diphenylmethane diisocyanate as the component (g) was 0.36 parts in the production of the biodegradable resin composition. A biodegradable resin composition was obtained.

Comparative Example 9 Biodegradation was carried out in the same manner as in Example 8 except that the amount of 4,4'-diphenylmethane diisocyanate as the component (g) was 36 parts in the production of the biodegradable resin composition. A resin composition was obtained. When a sheet-shaped molded body was prepared in the same manner as in Example 1, a large number of bubbles were contained, and a good molded body could not be obtained.

Comparative Example 10 Example 8 was repeated except that the component (g), 4,4′-diphenylmethane diisocyanate, was not used in the production of the biodegradable resin composition.
A biodegradable resin composition was obtained in the same manner as in. When a sheet-shaped molded body was prepared in the same manner as in Example 1, it was sticky and a good molded body could not be obtained.

Comparative Example 11 Biodegradability was the same as in Example 8 except that 100 parts of polycaprolactone having a melt viscosity of 200,000 poise was used as the component (d) in the production of the biodegradable resin composition. A resin composition was obtained.
Using the obtained biodegradable resin composition, an attempt was made to produce a sheet-like molded article having a thickness of 0.4 mm in the same manner as in Example 5, but the biodegradable resin composition had poor fluidity and a uniform thickness. Could not be obtained.

Using the 9 kinds of biodegradable resin compositions obtained in Examples 5 to 14, 10 kinds of unstretched sheet-like molded products (0.4 mm thick) were prepared in the same manner as in Example 1. .
Then, the performances of the 10 types of molded articles thus obtained were evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0086]

[Table 2]

Further, using the nine kinds of biodegradable resin compositions obtained in Comparative Examples 3 to 11, an unstretched sheet-shaped molded product (0.4 mm thick) was prepared in the same manner as in Example 1. It was Good moldings were not obtained from the compositions of Comparative Examples 9 and 10. The composition of Comparative Example 11 could not be formed into a uniform thickness. Then, the performance of the obtained molded body was evaluated in the same manner as in Example 1. The results are shown in Table 3.

[0088]

[Table 3]

[0089]

As described above, the biodegradable polyester composition according to the present invention has excellent flexibility and biodegradability and is relatively inexpensive.
It is suitable for a wide range of applications such as fibers.

Claims (4)

(57) [Claims] 1. To 100 parts by weight of the following component (a),
10 to 260 parts by weight of the component (b) and 0.5 to the component (c).
A biodegradable resin composition, which comprises mixing 10 parts by weight and reacting them. Component (a): Melt viscosity at 200 ° C. is 1000 to 1
Aliphatic polyester (b) component of 50,000 poise: biodegradable organic fine particles (c) component: polyfunctional isocyanate compound 2. With respect to 100 parts by weight of the following component (d),
The amount of the component (e) is 1 to 70 parts by weight, and the amount of the component (f) is 1 relative to 100 parts by weight of the total amount of the components (d) and (e).
A biodegradable resin composition, which is obtained by mixing 0 to 260 parts by weight and (g) component in an amount of 0.5 to 25 parts by weight and reacting them. Component (d): Melt viscosity at 200 ° C. is 1000 to 1
Aliphatic polyester (e) component having 50,000 poises: Aliphatic polyester (f) component having number average molecular weight of 500 to 5000: Biodegradable organic fine particles (g) component: Polyfunctional isocyanate compound 3. Component (e) (having a number average molecular weight of 500 to 5)
A biodegradable resin composition according to claim 2, characterized in that the aliphatic polyester of 000) is an oligomer of caprolactone. 4. The biodegradable polyester composition according to any one of claims 1 to 4, wherein the biodegradable organic fine particles are starches.