MOLDED ARTICLE, SHEET AND CONTAINER, AND TUBULAR ARTICLE, STRAW, COTTON SWAB, AND STICK FOR BALLOONS

Abstract

A molded article contains an aliphatic polyester-based resin composition. The aliphatic polyester-based resin composition contains an aliphatic polyester-based resin (A) containing a repeat unit derived from an aliphatic diol and a repeat unit derived from an aliphatic dicarboxylic acid as main structural units, a polyhydroxyalkanoate (B), and an inorganic filler (C). The polyhydroxyalkanoate (B) contains a 3-hydroxybutyrate unit and a 3-hydroxyhexanoate unit as main structural units. The mass ratio of the aliphatic polyester-based resin (A) to the polyhydroxyalkanoate (B) is 40/60 to 10/90. The amount of the inorganic filler (C) relative to the total amount of the aliphatic polyester-based resin (A), the polyhydroxyalkanoate (B), and the inorganic filler (C) is 15 to 50% by mass.

Claims

1. A molded article comprising an aliphatic polyester-based resin composition, wherein the aliphatic polyester-based resin composition contains an aliphatic polyester-based resin (A) containing a repeat unit derived from an aliphatic diol and a repeat unit derived from an aliphatic dicarboxylic acid as main structural units, a polyhydroxyalkanoate (B), and an inorganic filler (C), the polyhydroxyalkanoate (B) is a copolymer containing a 3-hydroxybutyrate unit and a 3-hydroxyhexanoate unit as main structural units, a mass ratio of the aliphatic polyester-based resin (A) to the polyhydroxyalkanoate (B) is 40/60 to 10/90, and an amount of the inorganic filler (C) relative to a total amount of the aliphatic polyester-based resin (A), the polyhydroxyalkanoate (B), and the inorganic filler (C) is 15 to 50% by mass.

2. The molded article according to claim 1, wherein the inorganic filler (C) is one or two or more selected from a group consisting of anhydrous silica, calcium carbonate, talc, and zeolite.

3. The molded article according to claim 1 or 2, wherein a ratio of a repeat unit derived from succinic acid to repeat units derived from all dicarboxylic acids contained in the aliphatic polyester-based resin (A) is 5% by mol or higher and 100% by mol or lower.

4. The molded article according to any one of claims 1 to 3 comprising the injection-molded article or an extrusion-molded article.

5. A sheet comprising the molded article according to any one of claims 1 to 4.

6. A container comprising the molded article according to any one of claims 1 to 4.

7. The container according to claim 6, wherein the container is a food packaging container.

8. A tubular article comprising an aliphatic polyester-based resin composition, wherein the aliphatic polyester-based resin composition contains an aliphatic polyester-based resin (A) containing a repeat unit derived from an aliphatic diol and a repeat unit derived from an aliphatic dicarboxylic acid as main structural units, a polyhydroxyalkanoate (B), and an inorganic filler (C), the polyhydroxyalkanoate (B) is a copolymer containing a 3-hydroxybutyrate unit and a 3-hydroxyhexanoate unit as main structural units, and an amount of the inorganic filler (C) relative to a total amount of the aliphatic polyester-based resin (A), the polyhydroxyalkanoate (B), and the inorganic filler (C) is 5 to 50% by mass.

9. The tubular article according to claim 8, wherein the inorganic Filler (C) is one or two or more selected from a group consisting of anhydrous silica, calcium carbonate, talc, and zeolite.

10. The tubular article according to claim 8 or 9, wherein a ratio of a repeat unit derived from succinic acid to repeat units derived from all dicarboxylic acids contained in the aliphatic polyester-based resin (A) is 5% by mol or higher and 100% by mol or lower.

11. The tubular article according to any one of claims 8 to 10 comprising an injection-molded article.

12. A straw comprising the tubular article according to any one of claims 8 to 11.

13. A cotton swab comprising the tubular article according to any one of claims 8 to 11.

14. A stick for balloons comprising the tubular article according to any one of claims 8 to 11.

15. A tubular article having an absolute or relative biodegradability of 60% or higher after 100 days in a marine biodegradation test (ASTM D6691) at a sea water temperature of 30 C.2 C.

16. A straw comprising the tubular article according to claim 15.

Description

EXAMPLES

[0199] Specific modes of the present invention will be described in more detail by way of Examples. However, the present invention is not limited to the following Examples so long as the invention does not depart from the scope thereof. Various production conditions and the values of evaluation results in the following Examples have meanings as preferred upper or lower limits in the embodiments of the present invention, and preferred ranges may be ranges defined by any combination of the above-described upper or lower limit values and values in the following Examples or any combination of the values in the following Examples.

[Measurement of Melt Flow Rate (MFR) of Resin Used]

[0200] Measurement was performed using a melt indexer at 190 C. and a load of 2.16 kg according to JIS K7210 (1999). The unit of the melt flow rate is g/10 min.

[Raw Materials Used]

[0201] Resins and inorganic fillers used in Examples and Comparative Examples are as follows;

[0202] Hereinafter, PBS refers to polybutylene succinate. PBSA refers to polybutylene succinate adipate. PLA refers to polylactic acid. PHBH refers to poly(3-hydroxybutyrate-co-3-hydroxyhexanoate). PBAT refers to polybutylene adipate terephthalate.

<Aliphatic Polyester-Based Resin (A)>

[0203] PBS-1 (BioPBS FZ71PM, manufactured by PTTMCC Biochem. Co., Ltd., MFR: 20.0 g/10 min, melting point: 113 C.)

[0204] PBS-2 (BioPBS FZ91PM, manufactured by PTTMCC Biochem Co., Ltd., MFR: 5.0 g/10 min, melting point: 113 C.)

[0205] PBSA-1 (BioPBS FD72PM, manufactured by PTTMCC Biochem Co., Ltd., the amount of succinic acid unit in the total amount of dicarboxylic acid units: 74% by mol, MFR: 20.0 g/10 min, melting point: 89 C.)

[0206] PBSA-2 (BioPBS FD92PM, manufactured by PTTMCC Biochem Co., Ltd., the amount of succinic acid unit in the total amount of dicarboxylic acid units: 74% by mol, MFR: 5.0 g/10 min, melting point: 89 C.)

<Polyhydroxyalkanoate (B)>

[0207] PHBH-1 (Aonilex X331N, manufactured by KANEKA CORPORATION, molar ratio of 3HB/3HH: 94/6, MFR: 30 g/10 min, melting point: 140 C.)

[0208] PHBH-2 (PHBH (trade name) X131A, manufactured by KANEKA CORPORATION, molar ratio of 3HB/3HH: 94/6, MFR: 6 g/10 min, melting point: 140 C.)

[0209] PHBH-3 (Aonilex (trade name) X151A, manufactured by KANEKA CORPORATION, molar ratio of 3HB/3HH: 89/11, MFR: 6 g/10 min, melting point: 131 C.)

<Polylactic Acid>

[0210] PLA-1 (4032D, manufactured by NatureWorks LLC, MFR: 3.5 g/10 min, melting point: 170 C.)

[0211] PLA-2 (3251D, manufactured by NatureWorks LLC, MFR: 29 g/10 min, melting point: 170 C.)

<Aliphatic/Aromatic Polyester>

[0212] PBAT (Ecoflex C1200, manufactured by BASF. Com, MFR: 4 g/10 min, melting point: 110 C.)

<Inorganic Filler (C)>vTalc-1 (MG-115, manufactured by FUJI TALC INDUSTRIAL CO., LTD., average particle diameter: 14 m)

[0213] Talc-2 (MICRO ACE K-1, manufactured by NIPPON TALC Co., Ltd., average particle diameter: 8 m)

[0214] Zeolite (MIZUKA LIZER-ES, manufactured by MIZUSAWA INDUSTRIAL CHEMICALS, LTD., average particle diameter: 2 m)

[0215] CaCO.sub.3 (SOFTON 1200, manufactured by BIHOKU FUNKA KOGYO CO., LTD., average particle diameter: 2 m)

[Examples and Comparative Examples of First Invention]

[Evaluation Method]

[0216] Methods for evaluating various physical properties and characteristics of Examples and Comparative Examples of the first invention are as follows.

<Water Vapor Permeability>

[0217] The measurement was performed using a cup method according to JIS 20208 (1976). The evaluation was performed under the measurement conditions of 23 C. and 83% RH, and the measured value was evaluated according to the following criteria.

[0218] : The water vapor permeability was less than 5 cc/m.sup.2.Math.day (the water vapor barrier property is high).

[0219] X: The water vapor permeability was 5 cc/m.sup.2.Math.day or more.

<Oxygen permeability>

[0220] The measurement was performed according to JIS K7126 (2006) under the conditions of a temperature of 23 C. and a humidity of 65% RH using a measurement device (device name: OXTRAN) manufactured by MOCON, U.S., and the measured value was evaluated according to the following criteria.

[0221] : The oxygen permeability was less than 100 g/m.sup.2 .Math.day (the oxygen barrier property is high).

[0222] X: The oxygen permeability was 100 g/m.sup.2.Math.day or more.

<H.D.T. (Heat Deflection Temperature)>

[0223] Heat deflection temperature was measured in conformity with JIS K7191 (2007). The higher the H.D.T., which is 90 C. or higher, the higher the heat resistance, which is preferable.

<Charpy Impact Strength>

[0224] Charpy impact strength was measured by using a test piece having a notch in conformity with JIS K7111 (2006). The higher the Charpy impact strength, which is 3 J/m or higher, the higher the impact resistance, which is preferable.

<Biodegradability Test>

[0225] After a sheet was stored for three months in microbially active soil, the sheet was subjected to mass measurement or appearance observation. The biodegradability was evaluated in accordance with the following criteria. The evaluation temperature was set to 282 C.

[0226] : Complete biodegradation was achieved.

[0227] : Partially biodegradation was achieved, but complete biodegradation was not achieved.

[0228] X: Almost no biodegradation was achieved.

Example I-1, Comparative Examples I-1 to 3

[0229] Materials in Table 1 were blended at the ratio in Table 1. The mixture was extruded in a strand shape from a twin-screw extruder with a screw diameter of 30 mm at a kneading temperature of 140 C., and thereafter, made into pellets by using a pelletizer. The obtained resin pellet was processed at 150 C. by using a single-screw extruder with a screw diameter of 50 mm and a hanger coat-type T-die with a width of 300 mm, and the taking-up speed was adjusted such that a sheet with a thickness of 100 m was obtained. Cooling temperature was set to 50 C. The chill roll was a semi-matt type roll, and an air knife was used. Regarding the obtained sheets, water vapor transmission rate and oxygen transmission rate were measured, and the biodegradation test was performed. The results are summarized in Table 1.

TABLE-US-00001 TABLE 1 Comparative Comparative Comparative Example Example Example Example I-1 I-1 I-2 I-3 Resin com- Aliphatic PBSA-2 24 30 position ratio polyester-based PBS-2 30 50 (% by mass) resin (A) Polyhydroxy- PHBH-2 56 70 70 alkanoate (B) Polylactic acid PLA-1 50 Inorganic filler Talc-1 20 (C) Evaluation Water vapor permeability x x x results Oxygen permeability x Biodegradability x (degradation ratio)

[0230] Table 1 shows the followings.

[0231] In Comparative Example I-1 in which the inorganic filler (C) is not contained, the water vapor barrier property is lower than that in Example I-1. In the same manner, in Comparative Example I-2, the water vapor barrier property and the biodegradability are low. In Comparative Example I-3 in which the polyhydroxyalkanoate (B) and polylactic acid are used, the water vapor barrier property, the oxygen barrier property, and the biodegradability are each significantly low.

[0232] In Example I-1 in which the aliphatic polyester-based resin (A), the polyhydroxyalkanoate (B), and the inorganic filler (C) are contained, the water vapor barrier property, the oxygen barrier property, and the biodegradability are excellent.

Examples I-2 to 3, Comparative Examples I-4 to 5

[0233] Materials in Table 2 were blended at the ratio in Table 2. The mixture was extruded in a strand shape by using a twin-screw extruder with a screw diameter of 30 mm at a kneading temperature of 140 C., and thereafter, made into pellets by using a pelletizer. The obtained resin pellet was subjected to injection molding at a mold temperature of 40 C. and a cylinder temperature of 150 C. to obtain an ISO test piece for a mechanical characteristics test. Regarding the obtained test piece, Charpy impact strength, H.D.T. were measured, and the biodegradability test was performed. The results are summarized in Table 2.

[0234] The cooling time in injection molding is shown in Table 2. The cooling time is the indicator of formability. The shorter the cooling time, the more excellent the moldability.

TABLE-US-00002 TABLE 2 Comparative Comparative Example Example Example Example I-2 I-3 I-4 I-5 Resin com- Aliphatic PBSA-1 20 20 position ratio polyester-based PBS-1 30 60 (% by mass) resin (A) Polyhydroxy- PHBH-1 50 50 60 alkanoate (B) Polylactic acid PLA-2 20 Inorganic filler Talc-1 30 30 (C) CaCO.sub.3 10 Zeolite 3 20 Evaluation H.D.T C. 95 95 96 89 results Charpy impact J/m 3 3 2 3 strength Biodegradability x Cooling Time sec 15 15 20 30

[0235] As shown in Table 2, in Examples I-2 and 3 in which the aliphatic polyester-based resin (A), the polyhydroxyalkanoate (B), and the inorganic filler (C) are contained within the range defined in the first invention, heat resistance and biodegradability are excellent, cooling time is short, and moldability is excellent.

[0236] In Comparative Example I-4, in which the aliphatic polyester-based resin (A), the polyhydroxyalkanoate (B), and the inorganic filler (C) are contained and in which the inorganic filler (C) content is low, biodegradability is low, cooling time is long, and moldability is lower than those in Examples I-2 and 3.

[0237] In Comparative Example I-5, in which polylactic acid is used in place of the aliphatic polyester-based resin (A), heat resistance, biodegradability, and moldability are low.

[Examples and Comparative Examples of Second Invention]

[Evaluation Method]

[0238] Methods for evaluating various physical properties and characteristics of Examples and Comparative Examples of the second invention are as follows.

<Evaluation of Moldability>

[0239] Moldability exhibited when straws were obtained by using a tube-shaped circular die was evaluated in accordance with the following criteria.

[0240] : Good samples are obtained without surging or faulty cutting.

[0241] X: Surging or faulty cutting occurs.

<Piercing Test>

[0242] The ends of 10 straws were cut at a 45 angle with general purpose scissors. A polyethylene film with a thickness of 40 m bonded to a cup was pierced with the end of the straw by hand from 3.5 cm above the film, and the state is evaluated in accordance with the following criteria.

[0243] : All 10 straws pierce the polyethylene film without breaking.

[0244] : Among 10 straws, 5 to 9 straws pierce the polyethylene film.

[0245] X: Among 10 straws, none pierce the polyethylene film.

<Odor Test>

[0246] Whether people sense odor when they drink mineral water by using a formed straw was evaluated by using 10 people. Evaluation criteria are as follows.

[0247] : Two or less people sense odor.

[0248] : Three or four people sense odor.

[0249] X: Five or more people sense odor.

<Elmendorf Tear Test>

[0250] Tear strength was measured in conformity with JIS K7128-2 (2007). The higher the tear strength, the more excellent the tear resistance, which is preferable.

<Biodegradability Test in Soil>

[0251] After a sheet was stored at 282 C. for three months in soil collected from a farm in Mie prefecture (water content 30%), the sheet was weighed, and the biodegradability was evaluated in accordance with the following criteria. Degradability was calculated from the following equation.

Degradability (%)=100(sample weight after 3 months/sample weight before test)100

[0252] : Degradability is 90% or higher.

[0253] : Degradability is 30% or higher and lower than 90%.

[0254] X: Degradability is lower than 30%.

<Biodegradability Test in Sea Water>

[0255] After a sheet was stored at 282 C. for six months in sea water collected from Yokkaichi port in Yokkaichi city Mie prefecture, the sheet was weighed, and the biodegradability was evaluated in accordance with the following criteria. Degradability was calculated from the following equation.

Degradability (%)=100(sample weight after 6 months/sample weight before test)100

[0256] : Degradability is 50% or higher.

[0257] : Degradability is 10% or higher and lower than 50%.

[0258] X: Degradability is lower than 10%.

<Marine Biodegradability Test (ASTM D6691)>

[0259] The amount of CO.sub.2 generated after 100 days from starting the test was measured in conformity with the test method of ASTM D6691, and biodegradability was calculated in conformity with the calculation method of ASTM D6691. In the test, sea water near Belgium was used. The measuring temperature was 302 C. The sample for evaluation was made into 60 mg powder having an average particle diameter of 250 m or less, and measurement was performed.

Examples II-1 to 6, Comparative Examples II-1 and 2

[0260] Materials in Table 3 were blended at the ratio in Table 3. The mixture was extruded in a strand shape from a twin-screw extruder with a screw diameter of ID 30 mm at a kneading temperature of 140 C., and thereafter, made into pellets by using a pelletizer. The obtained resin pellet was subjected to extrusion molding, and straws having a tubular shape with a diameter of 7 mm and a wall thickness of 0.2 mm were extruded by using a tube-type circular die. Thereafter, the piercing test and the odor test were performed. Only test pieces in Examples II-1, 3, 4, and 6 and Comparative Examples II-1 and 2 were subjected to the odor test.

[0261] A sheet with a thickness of 100 m was produced by pressing the obtained pellets. Then, biodegradation test in soil and biodegradation test in sea water were performed.

[0262] The obtained pellets were processed into powder having an average particle diameter of 250 m or less. The marine biodegradability of 60 mg of the powder was evaluated by the marine biodegradation test of ASTM D6691.

[0263] The results are summarized in Table 3.

[Comparative Example II-3]

[0264] In Comparative Example II-3, molding and evaluation were performed in the same manner as in Example II-1, except that the materials in Table 3 were blended at the ratio in Table 3 and that kneading was performed at 180 C.

TABLE-US-00003 TABLE 3 Comparative Comparative Comparative Example Example Example Example Example Example Example Example Example II-1 II-2 II-3 II-4 II-5 II-6 II-1 II-2 II-3 Resin com- Aliphatic PBSA-2 24 32 16 24 56 70 position ratio polyester-based PBS-2 16 (% by mass) resin (A) Polyhydroxy- PHBH-2 56 48 64 56 64 24 100 30 alkanoate (B) PHBH-3 Polylactic acid PLA-1 65 Aliphatic/ PBAT 20 aromatic polyester Inorganic filler Talc-1 20 20 10 15 (C) Talc-2 20 CaCO.sub.3 20 10 Evaluation Moldability x results Piercing property x Odor test x Biodegradability in soil x at room temperature Biodegradability in sea x water Marine biodegradability 67 64 70 68 70 52 100 51 (%)

Examples II-7, 8, Comparative Examples II-4

[0265] Materials in Table 4 were blended at the ratio in Table 4. The mixture was extruded in a strand shape by using a twin-screw extruder with a screw diameter of 30 mm at a kneading temperature of 140 C., and thereafter, made into pellets by using a pelletizer. The obtained resin pellet was molded at a molding temperature of 160 C. and a blow ratio of 2.5 by using a blown film molding machine with a screw diameter of 40 mm to obtain a tubular film with a wall thickness of 30 m. The film was subjected to the tear test. The obtained sheet was subjected to the biodegradation test in soil and the biodegradation test in sea water.

[0266] The results are summarized in Table 4.

[0267] Talc in Table 4 refers to Talc (manufactured by NIPPON TALC Co., Ltd. MICRO ACE K-1, average particle diameter: 8 m) .

TABLE-US-00004 TABLE 4 Example Example Comparative II-7 II-8 Example II-4 Resin composition Aliphatic polyester- PBSA-1 72 72 80 ratio (% by mass) based resin (A) PBS-1 Polyhydroxyalkanoate (B) PHBH-1 18 18 20 PHBH-2 Polylactic acid PLA Aliphatic/aromatic polyester PBAT Inorganic filler (C) Talc 10 CaCO.sub.3 10 Evaluation results Tear strength MD 2 2 2 (N/mm) TD 23 40 10 Biodegradability in soil at room temperature Biodegradability in sea water

[0268] Table 3 shows that the tubular article of the second invention has higher biodegradability at room temperature, higher biodegradability in sea water, more excellent moldability when a molded article is obtained, and more excellent characteristics, such as mechanical properties, for example, piercing strength, than a molded article containing a related biodegradable resin.

[0269] Table 4 shows that the tubular article of the second invention has high biodegradability at room temperature, excellent biodegradability in sea water, and high tear strength. Thus, when the tubular article is used as a tube formed of a film, tear is unlikely to occur.

[0270] Although the present invention has been described in detail by way of the specific modes, it is apparent for those skilled in the art that various changes can be made without departing from the spirit and scope of the present invention.

[0271] The present application is based on Japanese Patent Application No. 2018-067297 filed on Mar. 30, 2018, Japanese Patent Application No. 2018-161612 filed on Aug. 30, 2018, and Japanese Patent Application No. 2019-018067 filed on Feb. 4, 2019, the entire contents of which are incorporated herein by reference.

REFERENCE SIGNS LIST

[0272]