JP7163046B2 - biomass resin composition - Google Patents

Description

The present invention relates to biomass resin compositions.

Biomass resources are attracting attention from the viewpoint of energy consumption, utilization of fossil resources, and reduction of carbon dioxide emissions. However, even polylactic acid, which is a representative biomass resin and is synthesized as a plastic by polymerizing lactic acid, is inferior to ABS resin in strength and impact resistance, and is also a plastic with low heat resistance. Therefore, it is used together with a reinforcing agent such as glass fiber (see, for example, Patent Document 1).

On the other hand, cellulose is a main component of the cell walls of plant cells and plant fibers, and is a natural polymer in which a large number of β-glucose molecules are linearly polymerized through glycosidic bonds, and thus has a small environmental load. In this cellulose fiber, single cellulose nanofibers with a width of 3 to 4 nm, which are the basic units, are bundled to form cellulose nanofibers with a width of 10 to 20 nm, which are the basic units in the cell wall. It has a structure of bundles of several tens of μm. Cellulose nanofibers often contain hemicellulose and sometimes lignin in pulp or cellulose powder as raw materials, so cellulose nanofibers are often accompanied by these components, but the cellulose content is greater than 85% by mass based on the total weight. .

In recent years, these nanofibers have been found to have excellent properties such as high elastic modulus, high strength, low coefficient of linear expansion, and gas barrier properties, and are lighter than glass fibers, carbon fibers, inorganic fillers, etc. Therefore, research and development are being carried out on the assumption of various uses such as resin reinforcing materials, paint additives, films, and thickeners.

As a method for producing nanofibers, there is a method of mechanical defibration using a high-pressure dispersing device, a grinder, etc., and a simple mechanical defibration method using a kneader after chemically hydrophilizing the pulp with a cationizing agent. Examples include a method of fibrillating, a method of partially oxidizing using a TEMPO catalyst or the like to facilitate chemical fibrillation, and the like.

JP 2014-198820 A

Regarding biomass plastics, which are inferior in strength and heat resistance, attempts have been made to strengthen them by adding fillers. Can not.

For this reason, it is conceivable to use natural fibers as fillers to increase the biomass ratio and reduce weight. However, from the viewpoint of biodegradability and biogas refining, it is preferred that the constituent component is 100% by mass biomass material.

By the way, nanofibers are rarely used alone, and are often used in combination with organic components and organic solvents. As the fibers become thinner, hydrogen bonds between hydroxyl groups tend to agglomerate more strongly, and there are drawbacks such as a lack of affinity with hydrophobic organic substances. In other words, although it exists stably in water, it is difficult to combine with hydrophobic or hydrolyzable polymers (especially melt-kneading) in a water-rich state. There is a problem that it is difficult to exhibit the properties possessed by the nanofiber in the polymer because it becomes a foreign matter inside and deteriorates the properties.

Methods for hydrophobizing nanofibers have also been investigated, but most of them involve chemically substituting hydrophobic groups for hydroxyl groups of nanofibers. In that case, the cost is high, and since only a part of the hydroxyl groups are substituted, there remain problems such as the inability to suppress aggregation due to hydrogen bonding. In addition, the more hydrophobic the substituent becomes, the more bulky the substituent becomes, and the mass ratio to cellulose increases, which tends to impair the heat resistance and elastic modulus.

Although these problems are similar to those of ordinary cellulose fibers, they are problems that are particularly conspicuous in cellulose nanofibers in which a large number of hydroxyl groups are exposed on the surface relative to the mass.

Accordingly, an object of the present invention is to provide a biomass resin composition having high strength (high tensile strength, tensile elastic modulus and tensile elongation) without adding a non-biomass filler.

In view of the above object, as a result of intensive studies, the present inventors have found that all of the above problems can be solved by containing a biomass filler and a biomass resin so that the biomass ratio is 99% by mass or more. I found After further research, the present invention was completed. That is, the present invention includes the following configurations.
Section 1. containing biomass filler and biomass resin,
The biomass filler has a cellulose content of 60 to 85% by mass, and
A biomass resin composition having a biomass ratio of 99% by mass or more.
Section 2. Item 2. The biomass resin composition according to Item 1, wherein the biomass filler contains fibers having a diameter of less than 1 μm.
Item 3. The biomass filler contains both fibers with a diameter of less than 1 μm and fibers with a diameter of 1 μm or more, and the total amount of the fibers with a diameter of less than 1 μm and the fibers with a diameter of 1 μm or more is 100% by mass, and the content of the fibers with a diameter of less than 1 μm 3. The biomass resin composition according to item 1 or 2, wherein the is 5 to 80% by mass.
Section 4. Item 4. The biomass resin composition according to Item 2 or 3, wherein the fibers having a diameter of less than 1 μm are independently dispersed in the biomass resin.
Item 5. 5. The biomass resin composition according to any one of Items 1 to 4, wherein the content of the biomass filler is 5 to 80% by mass based on the total amount of the biomass resin composition being 100% by mass.
Item 6. The biomass resin is at least one selected from the group consisting of polylactic acid, polyglycolic acid, polyhydroxybutyrate, polybutylene succinate, polyethylene succinate, polyamide 4, polyamide 11, polyethylene, polypropylene and copolymers thereof. 6. The biomass resin composition according to any one of items 1 to 5, which is a biomass resin of
Item 7. 7. The biomass resin composition according to any one of Items 1 to 6, wherein the biomass filler is at least one biomass filler selected from the group consisting of flax, manila hemp, jute, ramie, sisal hemp and cotton.
Item 8. A method for producing a biomass resin composition according to any one of Items 1 to 7,
A manufacturing method comprising a kneading step of kneading the biomass filler and the biomass resin.
Item 9. Item 9. The production method according to Item 8, wherein the biomass filler is a biomass filler subjected to fibrillation treatment.
Item 10. Item 10. The production method according to Item 9, wherein the fibrillation treatment is performed once or twice.
Item 11. Item 11. The production method according to any one of Items 8 to 10, wherein the kneading is performed in a state in which an organic solvent is added.
Item 12. Item 12. The production method according to Item 11, wherein the organic solvent has at least one group selected from the group consisting of an oxyalkylene group, a ketone group, an ester group and a sulfinyl group.
Item 13. 13. The production method according to Item 11 or 12, wherein the organic solvent has at least one group selected from the group consisting of an oxyethylene group, an oxypropylene group, a cyclic ketone group, a cyclic ester group and a dialkylsulfoxide group.
Item 14. Item 14. The production method according to any one of Items 11 to 13, wherein the organic solvent does not have a hydroxyl group.
Item 15. Item 15. The production method according to any one of Items 11 to 14, wherein the organic solvent has a boiling point of 50 to 250°C.
Item 16. Item 11-, wherein the organic solvent is at least one selected from the group consisting of diethylene glycol dialkyl ether compounds, dipropylene glycol dialkyl ether compounds, aliphatic cyclic ketone compounds, alkyl acetate compounds, alkyl propionate compounds, and alkyl butyrate compounds. 16. The production method according to any one of 15.
Item 17. The organic solvent is diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, cyclohexanone, cyclopentanone, butyl acetate, pentyl acetate, isopentyl acetate, butyl butyrate, pentyl butyrate, isopentyl butyrate, dimethylsulfoxide, dimethylacetamide, N-methylpyrrolidinone and dimethylsulfoxide. The production method according to any one of claims 11 to 16, which is at least one selected from the group consisting of:

According to the present invention, it is possible to provide a high-strength biomass resin composition (high tensile strength, tensile modulus and tensile elongation) without adding a non-biomass filler.

1 is an optical microscope image of the biomass resin composition obtained in Example 1. FIG. 1 is a polarizing microscope image of the biomass resin composition obtained in Example 1. FIG. 2 is an optical microscope image of the biomass resin composition obtained in Example 2. FIG. 2 is a polarizing microscope image of the biomass resin composition obtained in Example 2. FIG. 4 is an optical microscope image of the biomass resin composition obtained in Example 3. FIG. 4 is a polarizing microscope image of the biomass resin composition obtained in Example 3. FIG. 4 is an optical microscope image of the biomass resin composition obtained in Example 4. FIG. 4 is a polarizing microscope image of the biomass resin composition obtained in Example 4. FIG. 4 is an optical microscope image of the biomass resin composition obtained in Example 5. FIG. 4 is a polarizing microscope image of the biomass resin composition obtained in Example 5. FIG. 4 is an optical microscope image of the biomass resin composition obtained in Example 6. FIG. 4 is a polarizing microscope image of the biomass resin composition obtained in Example 6. FIG.

As used herein, "contain" is a concept that includes both "comprise," "consist essentially of," and "consist of." In this specification, when a numerical range is represented by A to B, it means A or more and B or less.

The biomass resin composition of the present invention contains a biomass filler and a biomass resin, and the biomass filler has a cellulose content of 60 to 85% by mass and a biomass ratio of 99% by mass or more.

1. Biomass Filler The biomass filler used in the present invention is derived from biomass and added to improve the strength and heat resistance of the resin, and contains a high-strength and high-elasticity cellulose component.

The cellulose content of the biomass filler is 60% by mass or more, preferably 70% by mass or more, when the total amount of the biomass filler is 100% by mass. If the cellulose content of the biomass filler is less than 60% by mass, a biomass resin composition with high strength (high tensile strength, tensile elastic modulus and tensile elongation) cannot be obtained. On the other hand, the higher the cellulose content, the higher the strength of the biomass resin composition (higher tensile strength, tensile modulus and tensile elongation). When kneaded with biomass resin, the strength (tensile strength, tensile modulus and tensile elongation) decreases compared to biomass resin alone. From this point of view, the cellulose content of the biomass filler is 85% by mass or less, preferably 80% by mass or less.

The stalks of ordinary broadleaf trees, conifers, bagasse, bamboo, straw, etc. contain 35 to 50% by mass of cellulose, and the remaining main components are hemicellulose, lignin, and the like. In particular, hemicellulose is flexible, and if the content of hemicellulose is high, the strength is impaired. On the other hand, when treatment with alkali, acid, chlorine compounds, high-temperature water, etc. is performed to remove hemicellulose, lignin, etc., the degree of polymerization, crystallinity, etc. of cellulose may be impaired. Therefore, in the present invention, it is preferable that the untreated biomass filler has the above-described cellulose content. Examples of biomass fillers having such a cellulose content include flax, manila hemp, jute, ramie, sisal hemp, and cotton. These biomass fillers can be used alone or in combination of two or more.

The length of the biomass filler is not particularly limited, and is preferably 0.5 to 20 mm, more preferably 1 to 15 mm, from the viewpoint of obtaining a biomass resin composition with higher strength (larger tensile strength, tensile modulus and tensile elongation). .

The biomass filler preferably contains fibers with a diameter of less than 1 μm from the viewpoint of obtaining a biomass resin composition with higher strength (higher tensile strength, tensile modulus and tensile elongation). The biomass filler usually has a diameter of around 10 μm, and it is possible to reduce the diameter of some of the fibers to less than 1 μm by subjecting it to fibrillation treatment by a conventional method. However, from the viewpoint of strength (tensile strength, tensile modulus and tensile elongation), dispersibility, fiber length, degree of cellulose polymerization, etc., the biomass filler does not need to be completely defibrated. and fibers with a diameter of 1 μm or more. In addition, from the viewpoint of strength (tensile strength, tensile modulus and tensile elongation), dispersibility, fiber length, degree of polymerization of cellulose, etc., fibers with a diameter of less than 1 μm should be independently dispersed in the biomass resin. is preferred. For example, when producing the biomass resin composition of the present invention, the biomass filler and the biomass resin are melt-kneaded as described below, whereby fibers having a diameter of less than 1 μm are independently dispersed in the biomass resin of the present invention. A biomass resin composition can be obtained. The fibrillation treatment for producing fibers with a diameter of 1 μm or less may be either mechanical treatment or chemical treatment. A defibration treatment may be used, or a chemical defibration treatment using a TEMPO catalyst, phosphoric acid, dibasic acid, sulfuric acid, hydrochloric acid, or the like may be used. Among them, the method of adding shear by mechanical fibrillation treatment is preferable from the viewpoint of strength (tensile strength, tensile modulus and tensile elongation) reinforcement effect and cost by fibrillation treatment. Such fibrillation treatment can be used alone or in combination of two or more. In addition, such defibration treatment can be used only once, or can be repeated multiple times (for example, 2 to 10 times). Above all, it is preferable to perform the defibration treatment once or twice from the viewpoint of the strength (tensile strength, tensile modulus and tensile elongation) reinforcement effect and work efficiency due to the defibration treatment.

If the length of the biomass filler is less than 5 mm, the strength (tensile strength, tensile modulus and tensile elongation) can be further improved by performing the defibration treatment one or more times. is preferably applied 1 to 2 times or more. In addition, when the length of the biomass filler is 5 mm or more, the strength (tensile strength, tensile modulus and tensile elongation) can be further improved by performing fibrillation treatment once or twice.

When the biomass filler contains fibers with a diameter of less than 1 μm, the content thereof is equal to that of fibers with a diameter of less than 1 μm from the viewpoint of obtaining a biomass resin composition with higher strength (higher tensile strength, tensile modulus and tensile elongation). Taking the total amount of fibers with a diameter of 1 μm or more as 100% by mass, it is preferably 5 to 80% by mass (especially 30 to 70% by mass) when the length of the biomass filler is less than 5 mm, and when the length of the biomass filler is 5 mm or more. is preferably 30 to 70% by mass.

2. Biomass resin Biomass resin can be used as long as it is a biomass-derived resin, such as polylactic acid, polyglycolic acid, polyhydroxybutyrate, polybutylene succinate, polyethylene succinate, polyamide 4, polyamide 11, polyethylene, polypropylene, copolymers thereof, and the like. The resin may be a chemically modified resin containing a biomass material as a main component, such as cellulose acetate. These biomass resins can be used alone or in combination of two or more. From the viewpoint of biodegradation or biogas generation, it is preferable to have biodegradability, and from the viewpoint of long-term durability, it is preferable to have no biodegradability.

3. Biomass resin composition The biomass resin composition of the present invention contains a biomass filler from the viewpoint of obtaining a biomass resin composition with higher strength (larger tensile strength, tensile modulus and tensile elongation) without impairing fluidity. The amount is preferably 5 to 80% by mass, more preferably 8 to 50% by mass, based on 100% by mass of the total amount of the biomass resin composition. Moreover, the content of the biomass resin is preferably 20 to 95% by mass, more preferably 50 to 92% by mass, based on the total amount of the biomass resin composition being 100% by mass.

Moreover, the biomass resin composition of the present invention has a biomass ratio of 99% by mass or more, preferably 99.5% by mass or more, and most preferably 100% by mass, from the viewpoint of biodegradability and biogas purification.

Such a biomass resin composition of the present invention can be obtained by a production method comprising a kneading step of kneading a biomass filler and a biomass resin.

The above-described biomass filler and biomass resin can be employed, and the biomass filler subjected to fibrillation treatment as described above can also be used. The same applies to preferable conditions.

The kneading method is not particularly limited, and may be dry kneading or melt kneading (for example, melt kneading in an organic solvent). In particular, melt-kneading is preferred from the viewpoint of productivity, dispersibility and strength (tensile strength, tensile modulus and tensile elongation). If the length of the biomass filler is less than 5 mm, from the viewpoint of strength (tensile strength, tensile modulus and tensile elongation), the biomass filler that has undergone fibrillation treatment once or more is used for dry kneading or melting. It is preferable to perform kneading, and it is more preferable to perform melt-kneading using a biomass filler that has been defibrated once or twice. In addition, if the length of the biomass filler is 5 mm or more, from the viewpoint of strength (tensile strength, tensile modulus and tensile elongation), melt kneading using biomass filler that has undergone fibrillation treatment once or twice. preferably applied.

When melt-kneading is employed, the organic solvent is preferably removed after the organic solvent used enhances the affinity between the biomass filler and the biomass resin during kneading. The boiling point of the organic solvent is preferably 50 to 250°C, more preferably 70 to 230°C, from the viewpoints of particularly excellent workability in this case, the biomass filler being particularly difficult to aggregate, and the organic solvent being particularly easy to remove.

In addition, when using polyester resin, polyamide resin, etc. that cause hydrolysis or alcoholysis as biomass resin, the organic solvent must not have a hydroxyl group in order to prevent unnecessary reactions with the biomass resin. is preferred.

Moreover, it is preferable that the organic solvent to be used has high affinity with the biomass filler. From the viewpoint of the affinity of the biomass filler with cellulose, the organic solvent preferably contains at least one of an oxyalkylene group, a ketone group, an ester group, a sulfinyl group, and the like. In addition, from the viewpoint that the organic solvent increases the affinity between the raw materials during kneading, it is preferable that the organic solvent used can dissolve the biomass resin at a high temperature range (for example, 60 to 240 ° C.) that does not significantly deteriorate the cellulose.

The organic solvent that satisfies these conditions preferably contains at least one of oxyethylene group, oxypropylene group, cyclic ketone group, cyclic ester group, dialkylsulfoxide group, etc. Diethylene glycol dialkyl ether compound, dipropylene glycol dialkyl. Ether compounds, aliphatic cyclic ketone compounds, alkyl acetate compounds, alkyl propionate compounds, alkyl butyrate compounds, and the like are suitable. Diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, cyclohexanone, cyclopentanone, butyl acetate, pentyl acetate, isopentyl acetate, butyl butyrate, pentyl butyrate, isopentyl butyrate, dimethylsulfoxide, dimethylacetamide, N-methylpyrrolidinone, dimethylsulfoxide and the like are particularly preferred. These organic solvents can be used alone or in combination of two or more. However, the organic solvent is not necessarily limited to these, and is preferably selected from the viewpoint of affinity with the biomass filler and biomass resin to be used.

The present invention will be specifically described based on Examples, but the present invention is not limited to these.

In the following examples and comparative examples, the biomass filler and the biomass resin were mixed by melt-kneading. Specifically, a biomass resin dried at 80 ° C. for 24 hours and a predetermined biomass filler are extruded using a twin-screw extruder (manufactured by Technobell Co., Ltd.; screw diameter 15 mmφ, screw process length L / D = 30). The mixture was melt-kneaded to obtain a compound. The resulting compound was dried at 80°C for 24 hours, and then molded into a length of 75 mm, parallel width of 5 mm, and parallel length of 35 mm using an injection molding machine (C, MOBILE-0813, manufactured by Shinko Cellbic Co., Ltd.). It was molded into a dumbbell specimen with a thickness of ×2 mm. The test piece was subjected to a tensile test using a universal material testing machine (Instron 5567) at an ambient temperature of 23° C., a tensile speed of 10 mm/min, n=5, and the tensile strength, tensile modulus and tensile elongation were calculated.

[Example 1: PLA + sisal 10 mm, no fibrillation, DRY]
20 g of sisal hemp cut to a length of 10 mm and 180 g of polylactic acid (TERRAMAC TE-2000 manufactured by Unitika Ltd.) were kneaded at 220° C. to obtain 150 g of a resin composition having a biomass ratio of 100% by mass. This biomass resin composition had a tensile strength of 73.1 MPa, a tensile modulus of 1425 MPa, and a tensile elongation of 6.7 % .

When the obtained biomass resin composition was pressed and observed with an optical microscope, the fibers were finely dispersed. The results are shown in FIG. Further, when observed with a polarizing microscope, all the sisal fibers were cleaved to a thickness of about 10 μm. The results are shown in FIG.

[Example 2: PLA + sisal hemp 10 mm, fibrillation 1 PASS, WET]
1000 g of diethylene glycol dimethyl ether was added to 20 g (dry weight) of 10 mm sisal hemp that had been fibrillated once by a grinder method and was moistened with water, and the pressure was reduced at 80° C. to obtain sisal hemp moistened with diethylene glycol dimethyl ether. This wet sisal hemp and 180 g of polylactic acid (TERRAMAC TE-2000 manufactured by Unitika Ltd.) were kneaded at 220° C. to obtain 150 g of a resin composition having a biomass ratio of 100 mass %. This biomass resin composition had a tensile strength of 77.2 MPa, a tensile modulus of 1440 MPa, and a tensile elongation of 7.1 % . Thus, compared with Example 1, the strength (tensile strength, tensile modulus and tensile elongation) was improved.

When the obtained biomass resin composition was pressed and observed with an optical microscope, fine fibers were uniformly dispersed singly and no aggregation was observed. The results are shown in FIG. In addition, when observed with a polarizing microscope, sisal fibers are a mixture of fibers with a thickness of about 10 μm (about 30% by mass) and fibers with a thickness of 1 μm or less (about 70% by mass). Many fibers were found. The results are shown in FIG.

[Example 3: PLA + 2 mm sisal hemp, no fibrillation, DRY]
20 g of sisal hemp cut to a length of 2 mm and 180 g of polylactic acid (TERRAMAC TE-2000 manufactured by Unitika Ltd.) were kneaded at 220° C. to obtain 150 g of a resin composition having a biomass ratio of 100% by mass. This biomass resin composition had a tensile strength of 68.8 MPa, a tensile modulus of 1404 MPa, and a tensile elongation of 5.7 % .

When the obtained biomass resin composition was pressed and observed with an optical microscope, the fibers were finely dispersed. The results are shown in FIG. Further, when observed with a polarizing microscope, all the sisal fibers were cleaved to a thickness of about 10 μm. The results are shown in FIG.

[Example 4: PLA + sisal hemp 2 mm, fibrillation 1 PASS, DRY]
20g of 2mm sisal hemp that had been fibrillated once by the grinder method and dried at 130°C for 24 hours, and 180g of polylactic acid (TERRAMAC TE-2000 manufactured by Unitika Ltd.) were kneaded at 220°C to obtain 150g of biomass ratio of 100 mass. % resin composition was obtained. This biomass resin composition had a tensile strength of 70.6 MPa, a tensile modulus of 1433 MPa, and a tensile elongation of 6.2 % .

When the obtained biomass resin composition was pressed and observed with an optical microscope, it was found that finer fibers than in Example 3 were uniformly dispersed in some areas and aggregated in some areas. The results are shown in FIG. Further, when observed with a polarizing microscope, the sisal fibers were found to be a mixture of fibers with a thickness of about 10 μm (about 80% by mass) and fibers with a thickness of 1 μm or less (about 20% by mass). The results are shown in FIG.

[Example 5: PLA + sisal hemp 2 mm, fibrillation 1 PASS, WET]
1000 g of diethylene glycol dimethyl ether was added to 20 g (dry weight) of 2 mm sisal hemp that had been fibrillated once by a grinder method and was moistened with water, and the pressure was reduced at 80° C. to obtain sisal hemp moistened with diethylene glycol dimethyl ether. This wet sisal hemp and 180 g of polylactic acid (TERRAMAC TE-2000 manufactured by Unitika Ltd.) were kneaded at 220° C. to obtain 150 g of a resin composition having a biomass ratio of 100 mass %. This biomass resin composition had a tensile strength of 75.5 MPa, a tensile modulus of 1418 MPa, and a tensile elongation of 6.3 % . Thus, compared with Examples 3 and 4, the strength (tensile strength, tensile modulus and tensile elongation) was further improved.

When the obtained biomass resin composition was pressed and observed with an optical microscope, fine fibers were dispersed more uniformly than in Example 4, and aggregation was not observed. The results are shown in FIG. In addition, when observing with a polarizing microscope, sisal fibers are a mixture of fibers with a thickness of about 10 μm (about 50% by mass) and fibers with a thickness of 1 μm or less (about 50% by mass). Many fibers were found. The results are shown in FIG.

[Example 6: PLA + sisal hemp 2mm, fibrillation 3PASS, WET]
1000 g of diethylene glycol dimethyl ether was added to 20 g (dry weight) of 2 mm sisal hemp that had been fibrillated three times by a grinder method and was moistened with water, and the pressure was reduced at 80° C. to obtain sisal hemp wetted with diethylene glycol dimethyl ether. This wet sisal hemp and 180 g of polylactic acid (TERRAMAC TE-2000 manufactured by Unitika Ltd.) were kneaded at 220° C. to obtain 150 g of a resin composition having a biomass ratio of 100 mass %. This biomass resin composition had a tensile strength of 72.2 MPa, a tensile modulus of 1394 MPa, and a tensile elongation of 7.0 % .

When the obtained biomass resin composition was pressed and observed with an optical microscope, fine fibers were more uniformly dispersed than in Examples 4 and 5. The results are shown in FIG. In addition, when observing with a polarizing microscope, the sisal fibers were mixed with fibers with a thickness of about 10 μm (about 15% by mass) and fibers with a thickness of 1 μm or less (about 85% by mass). Although many finer fibers than in Example 5 were observed, the fiber length was shorter than in Example 5. The results are shown in FIG.

[Comparative Example 1: PLA]
Polylactic acid (TERRAMAC TE-2000 manufactured by Unitika Ltd.) was melt-kneaded using a twin-screw extruder, dried at 80°C for 24 hours, and molded into a dumbbell test piece using an injection molding machine. When the tensile strength, tensile modulus and tensile elongation of the test piece were measured, the tensile strength was 60.9 MPa, the tensile modulus was 1198 MPa and the tensile elongation was 5.7 % .

[Comparative Example 2: PLA + cellulose fiber, no fibrillation, DRY]
20 g of cellulose fiber (W-50GK manufactured by Nippon Paper Industries Co., Ltd.) and 180 g of polylactic acid (TERRAMAC TE-2000 manufactured by Unitika Ltd.) were kneaded at 220°C to prepare 150 g of a resin composition with a biomass ratio of 100% by mass. Obtained. This biomass resin composition had a tensile strength of 58.8 MPa, a tensile modulus of 1265 MPa, and a tensile elongation of 5.2 % , which were lower than those of polylactic acid alone.

[Comparative Example 3: PLA + cellulose fiber, fibrillation 1PASS, WET]
1000 g of diethylene glycol dimethyl ether is added to 20 g (dry weight) of 10 mm cellulose fiber (W-50GK manufactured by Nippon Paper Industries Co., Ltd.) that has been fibrillated once by the grinder method and moistened with water. A wet cellulose fiber was obtained. This wet cellulose fiber and 180 g of polylactic acid (TERRAMAC TE-2000 manufactured by Unitika Ltd.) were kneaded at 220° C. to obtain 150 g of a resin composition having a biomass ratio of 100% by mass. This biomass resin composition had a tensile strength of 57.3 MPa, a tensile modulus of 1268 MPa, and a tensile elongation of 6.4 % . Thus, compared with Comparative Examples 1 and 2, the strength (tensile strength, tensile modulus and tensile elongation) was further reduced.

In the case of the cellulose fibers of Comparative Examples 2 and 3 (the cellulose content is more than 85% by mass), by mixing with polylactic acid, the strength (tensile strength, tensile modulus and tensile elongation ) decreased, and when the cellulose fibers were defibrated, the strength (tensile strength, tensile modulus and tensile elongation) decreased further. In contrast, when sisal hemp with a cellulose content of 60 to 85% by mass is used, the strength (tensile strength, tensile modulus and tensile elongation) is improved compared to polylactic acid alone, and sisal hemp is used. Defibering further improved the strength (tensile strength, tensile modulus and tensile elongation). This result is contrary to the case of using cellulose fibers and is an unexpected effect.

Claims (15)

containing biomass filler and biomass resin,
The biomass filler has a cellulose content of 60 to 85% by mass, and
The biomass ratio is 99% by mass or more,
The biomass filler is at least one biomass filler selected from the group consisting of flax, Manila hemp, jute and sisal hemp,
A biomass resin composition, wherein the biomass filler contains fibers having a diameter of less than 1 μm. The biomass filler contains both fibers with a diameter of less than 1 μm and fibers with a diameter of 1 μm or more, and the total amount of the fibers with a diameter of less than 1 μm and the fibers with a diameter of 1 μm or more is 100% by mass. 2. The biomass resin composition according to claim 1, wherein the content is 5-80% by mass. 3. The biomass resin composition according to claim 1 or 2, wherein said fibers having a diameter of less than 1 [mu]m are independently dispersed in said biomass resin. The biomass resin composition according to any one of claims 1 to 3, wherein the content of the biomass filler is 5 to 80% by mass based on the total amount of the biomass resin composition being 100% by mass. The biomass resin is at least one selected from the group consisting of polylactic acid, polyglycolic acid, polyhydroxybutyrate, polybutylene succinate, polyethylene succinate, polyamide 4, polyamide 11, polyethylene, polypropylene and copolymers thereof. The biomass resin composition according to any one of claims 1 to 4, which is a biomass resin of A method for producing a biomass resin composition according to any one of claims 1 to 5,
A manufacturing method comprising a kneading step of kneading the biomass filler and the biomass resin. 7. The production method according to claim 6, wherein the biomass filler is a biomass filler subjected to fibrillation treatment. The production method according to claim 7, wherein the fibrillation treatment is performed once or twice. The production method according to any one of claims 6 to 8, wherein said kneading is performed in an organic solvent. 10. The production method according to claim 9, wherein the organic solvent has at least one group selected from the group consisting of an oxyalkylene group, a ketone group, an ester group and a sulfinyl group. 11. The production method according to claim 9 or 10, wherein the organic solvent has at least one group selected from the group consisting of an oxyethylene group, an oxypropylene group, a cyclic ketone group, a cyclic ester group and a dialkylsulfoxide group. The production method according to any one of claims 9 to 11, wherein the organic solvent does not have a hydroxyl group. The production method according to any one of claims 9 to 12, wherein the organic solvent has a boiling point of 50 to 250°C. The organic solvent is at least one selected from the group consisting of diethylene glycol dialkyl ether compounds, dipropylene glycol dialkyl ether compounds, aliphatic cyclic ketone compounds, alkyl acetate compounds, alkyl propionate compounds, and alkyl butyrate compounds. 11. The production method according to 9 or 10 . The organic solvent is diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, cyclohexanone, cyclopentanone, butyl acetate, pentyl acetate, isopentyl acetate, butyl butyrate, pentyl butyrate, isopentyl butyrate, dimethylsulfoxide, dimethylacetamide, and N- methylpyrrolidinone . 10. The production method according to claim 9, which is at least one selected from the group consisting of:

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