Resin composition, resin molded article, and method for producing resin pellets

Abstract

The invention provides a method for producing a resin composition. The method comprises the step of mixing plant fibers, polyolefin resin and at least one compound of a first cyclic compound, a second cyclic compound, a third cyclic compound and a fourth cyclic compound to obtain the resin composition.

Description

Technical Field

[0001] This invention relates to a method for manufacturing resin compositions containing plant fibers and polyolefin resins, resin molded articles, and resin particles. Background Technology

[0002] In the past, to ensure the strength of resin compositions, methods were employed that incorporated plant fibers or inorganic raw materials such as calcium carbonate, talc, or glass fiber as fillers into the synthetic resin (polyolefin resin) as the matrix. In particular, plant fibers are lighter than inorganic raw materials, so using plant fibers as fillers is a method to improve the strength of resin compositions and achieve weight reduction.

[0003] However, when plant fibers, composed of lignin and hemicellulose, are heated to high temperatures (around 200°C), the lignin and hemicellulose undergo thermal decomposition, producing corrosive gases such as carboxylic acids. Therefore, if a resin composition containing plant fibers and synthetic resin is injection molded at high temperatures, it may corrode the mold used for injection molding.

[0004] For example, Patent Document 1 discloses a method for manufacturing a resin composition for molding materials containing plant fibers, thermoplastic resin, and a compound that is reactive with carboxyl groups.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 6986655

[0008] Invention Summary

[0009] However, when the molecular weight of carboxylic acids is small and the compound that reacts with carboxylic acids is a chain-like carbodiimide, the problem of producing isocyanate gas may occur.

[0010] The present invention was made in view of the above-mentioned problems, and its object is to provide a resin composition, a resin molded body, and a method for manufacturing resin particles that can suppress mold corrosion and prevent the generation of isocyanate gas during injection molding.

[0011] The problem that the invention aims to solve

[0012] The method for manufacturing the resin composition of the present invention includes the step of compounding plant fibers, polyolefin resins, and at least one compound selected from a first cyclic compound, a second cyclic compound, a third cyclic compound, and a fourth cyclic compound to obtain the resin composition. The first cyclic compound is a cyclic compound having a main cyclic structure and two or more first subcyclic structures, wherein the main cyclic structure comprises a carbodiimide formed by bonding a first nitrogen and a second nitrogen through a bonding group, and the two or more first subcyclic structures are fused with a portion of the main cyclic structure; the second cyclic compound is a cyclic compound having the main cyclic structure and two or more second subcyclic structures extending from the main cyclic structure as substituents; the third cyclic compound has the main cyclic structure, a first subcyclic structure fused with a portion of the main cyclic structure, and second subcyclic structures extending from the first subcyclic structure as substituents; the fourth cyclic compound is a cyclic compound having the main cyclic structure, a first subcyclic structure fused with a portion of the main cyclic structure, and a second subcyclic structure fused with a portion of the first subcyclic structure.

[0013] Brief description of the attached diagram

[0014] Figure 1 This is a diagram illustrating the manufacturing steps of the resin composition and resin molded article according to the first embodiment of the present invention.

[0015] Figure 2 It is a diagram showing the reaction process between corrosive gases and cyclic compounds.

[0016] Figure 3 This is a diagram illustrating the manufacturing steps of the resin composition and resin molded body of a modified example 1 of the first embodiment of the present invention.

[0017] Figure 4 This is a diagram illustrating the manufacturing steps of resin particles according to a modified example 2 of the first embodiment of the present invention.

[0018] Figure 5 This is a diagram illustrating the manufacturing steps of the resin composition and resin molded article according to the second embodiment of the present invention.

[0019] Figure 6 This is a table summarizing the comparison results of examples and comparative examples of the resin compositions of the present invention. Detailed Implementation

[0020] (First Implementation)

[0021] The first embodiment of the present invention will be described. For example... Figure 1As shown, in the method for manufacturing the resin composition according to the first embodiment, plant fiber 10, polyolefin resin 11, and cyclic compound 20 having carbodiimide groups are mixed using a twin-shaft mixer 40 at a screw speed of 250 rpm and a barrel temperature of 200 degrees Celsius to obtain resin composition 30. Next, resin composition 30 is injected into a molding machine 41 and injection molded at a high temperature to obtain resin molded body 31. It should be noted that the screw speed and barrel temperature in the twin-shaft mixer can be appropriately varied. Furthermore, the mixing apparatus is not limited to a twin-shaft mixer.

[0022] Plant fiber 10 refers to natural fibers collected from plants, whose main components are cellulose, hemicellulose, and lignin, which are structural components of plant cell walls. For example... Figure 2 As shown, hemicellulose and lignin undergo thermal decomposition at high temperatures (approximately 200°C) to produce carboxylic acid, which is a corrosive gas 10A.

[0023] The carboxylic acid produced from plant fiber 10 reacts with cyclic compound 20. That is, the carboxylic acid is masked by cyclic compound 20. Therefore, it is possible to inhibit the carboxylic acid from reacting with the mold (e.g., iron) used for injection molding and thus preventing corrosion of the mold. The reaction mechanism of carboxylic acid with cyclic compound 20 is shown below.

[0024] (Chemical Formula 1)

[0025] Furthermore, by using cyclic compound 20 and following the above-described reaction mechanism, the generation of isocyanate gas can be prevented. That is, by incorporating cyclic compound 20 into plant fiber 10 and polyolefin resin 11 and then compounding them, the corrosion of the mold by carboxylic acid produced by plant fiber 10 can be suppressed, and the generation of isocyanate gas can be prevented.

[0026] It should be noted that isocyanate gas can be generated, for example, in the following situations: the carboxylic acid produced from plant fibers has a small molecular weight, and the compound that reacts with the carboxylic acid is a chain-like carbodiimide.

[0027] Furthermore, by using cyclic compound 20 and following the above-described reaction mechanism, atomization of isocyanate gas originating from the resin composition can be prevented. Atomization of isocyanate gas refers to the evaporation of isocyanate gas from the resin composition due to high temperature.

[0028] As the plant fiber 10 used in the resin composition of the present invention, wood flour, paper or other wood fibers, cellulose fibers, cellulose nanofibers, biomass materials derived from plants, cellulose, hemicellulose, lignin, etc., extracted from plants or synthesized separately can be used. In addition, as wood flour, for example, wood flour derived from the following plants can be used: conifers, broad-leaved trees, rice straw, rice husks, wheat straw, bamboo, pine, cedar, cypress, kenaf, pulp, sisal, Manila hemp, jute, coconut, corn, reeds, palm, papyrus.

[0029] It should be noted that wood flour derived from coniferous trees is preferably used as the plant fiber 10. When comparing coniferous and broadleaf trees, the amount of cellulose remains the same, but coniferous trees have a higher amount of lignin and a lower amount of hemicellulose compared to broadleaf trees. The thermal decomposition temperature of hemicellulose is 180–300°C, while that of lignin is 280–550°C. Therefore, coniferous trees, with their relatively lower hemicellulose and relatively higher lignin content, exhibit higher heat resistance. Thus, by using wood flour derived from coniferous trees as the plant fiber 10, the heat resistance of the resin composition 30 can be improved.

[0030] The amount of plant fiber 10 relative to the total amount of resin composition 30 is preferably 10 to 85% by weight, more preferably 30 to 70% by weight. If the amount of plant fiber is low, it is difficult to ensure sufficient strength; therefore, the amount of plant fiber is preferably 10% by weight or more, more preferably 30% by weight or more. Furthermore, while a higher amount of plant fiber results in greater strength, it also reduces the fluidity of the resin composition, making it difficult to fully mix. Therefore, the amount of plant fiber is preferably 85% by weight or less, more preferably 70% by weight or less. Additionally, the reduced fluidity of the resin composition also makes it difficult to ensure sufficient moldability.

[0031] As a polyolefin resin 11, polypropylene (PP), polyethylene (PE), etc. can be used.

[0032] The amount of polyolefin resin 11 relative to the total amount of resin composition 30 is preferably 15 to 90% by weight, more preferably 30 to 70% by weight. When the amount of polyolefin resin is low, the fluidity of the resin composition decreases, making thorough mixing difficult. Therefore, the amount of polyolefin resin is preferably 15% by weight or more, more preferably 30% by weight or more. Conversely, when the amount of polyolefin resin is high, sufficient strength is difficult to ensure. Therefore, the amount of polyolefin resin is preferably 90% by weight or less, more preferably 70% by weight or less. Furthermore, since polyolefin resins are derived from fossil fuels such as petroleum, reducing the amount of polyolefin resin is also beneficial from the perspective of environmental resource conservation.

[0033] Cyclic compound 20 is any one of the following first cyclic compound, second cyclic compound, third cyclic compound and fourth cyclic compound.

[0034] A first cyclic compound is a cyclic compound having a main ring structure and two or more first subcyclic structures, wherein the main ring structure comprises a carbodiimide formed by the bonding of a first nitrogen and a second nitrogen through a bonding group, and the first subcyclic structure is fused to a portion of the main ring structure. The main ring structure refers to the structure with the minimum number of bonds required to form a cyclic carbodiimide. It should be noted that a first cyclic compound may have multiple main ring structures. Furthermore, the bonding group refers to the carbon atom constituting the carbodiimide group. Additionally, the first nitrogen and the second nitrogen refer to nitrogen atoms respectively bonded to the carbon atom serving as the bonding group.

[0035] As the first cyclic compound, compounds (1) to (26) below can be used, for example. It should be noted that, from the perspective of ease of synthesis and low cost of raw materials, compound (1) below is preferred as the first cyclic compound.

[0036] (Chemical Formula 2)

[0037] (Chemical Formula 3)

[0038] (Chemical Formula 4)

[0039] A second cyclic compound is a cyclic compound having a main cyclic structure and two or more second subcyclic structures. The main cyclic structure comprises a carbodiimide formed by the bonding of a first nitrogen atom and a second nitrogen atom through a bonding group. The second subcyclic structure extends from the main cyclic structure as a substituent. The main cyclic structure refers to the structure with the minimum number of bonds required to form a cyclic carbodiimide. Furthermore, the bonding group refers to the carbon atom constituting the carbodiimide group. Additionally, the first nitrogen atom and the second nitrogen atom refer to nitrogen atoms respectively bonded to the carbon atom serving as the bonding group.

[0040] For example, the following compounds (27) to (30) can be used as second cyclic compounds.

[0041] (Chemical Formula 5)

[0042] A third-cyclic compound is a cyclic compound having a main ring structure, a first subcyclic structure fused to a portion of the main ring structure, and a second subcyclic structure extending from the first subcyclic structure as a substituent, wherein the main ring structure comprises a carbodiimide with a first nitrogen atom and a second nitrogen atom bonded by a bonding group. The main ring structure refers to the structure with the minimum number of bonds required to form a cyclic carbodiimide. Furthermore, the bonding group refers to the carbon atom constituting the carbodiimide group. Additionally, the first nitrogen atom and the second nitrogen atom refer to nitrogen atoms respectively bonded to the carbon atom serving as the bonding group.

[0043] For example, the following compounds (31) to (32) can be used as tricyclic compounds.

[0044] (Chemical Formula 6)

[0045] The fourth cyclic compound is a cyclic compound having a main cyclic structure, a first subcyclic structure fused to a portion of the main cyclic structure, and a second subcyclic structure fused to a portion of the first subcyclic structure, wherein the main cyclic structure comprises a carbodiimide with the first nitrogen and the second nitrogen bonded by a bonding group.

[0046] For example, the following compounds (33) to (35) can be used as fourth-cyclic compounds.

[0047] (Chemical Formula 7)

[0048] Alternatively, the fourth cyclic compound may be a cyclic compound having a main cyclic structure as shown in compound (35), a first subcyclic structure fused to a portion of the main cyclic structure, a second subcyclic structure fused to a portion of the first subcyclic structure, and a third subcyclic structure fused to a portion of the second subcyclic structure, wherein the main cyclic structure comprises a carbodiimide bonded to a first nitrogen and a second nitrogen by a bonding group.

[0049] (Chemical Formula 8)

[0050] The amount of cyclic compound 20 relative to plant fiber 10 is preferably 0.05 to 5.00% by weight. When the amount of cyclic compound is less than 0.05% by weight, the amount of cyclic compound relative to corrosive gas 10A is insufficient, and therefore a large amount of corrosive gas 10A remains in an unreacted state. As a result, the suppression of corrosion of the mold used during molding becomes insufficient.

[0051] It should be noted that the amount of cyclic compound 20 is preferably set at 0.5% by weight or more, and wood flour derived from coniferous trees is used as plant fiber 10. By setting the amount of cyclic compound 20 at 0.5% by weight or more and using wood flour derived from coniferous trees as plant fiber 10, corrosion resistance can be further improved.

[0052] The uses of the resin molded body 31 made from the resin composition 30 of the present invention are not particularly limited, and it can be used in automotive exterior and interior trim, lighting equipment, camera, sensor and other imaging equipment, display items, stationery and other daily necessities, etc. In particular, the resin molded body 31 made using the resin composition 30 of the present invention can prevent atomization of isocyanate gas at high temperatures, and therefore it is advantageous for components of devices such as housings or brackets of vehicle lamps that have heat sources with temperatures below 300°C.

[0053] The first embodiment will now be described in more detail using modified examples. It should be noted that the present invention is not limited to these modified examples.

[0054] (Modification 1 of the first embodiment)

[0055] A variation of the method for manufacturing the resin composition according to the first embodiment will be described. For example... Figure 3 As shown, in a variation 1 of the method for manufacturing the resin composition according to this embodiment, for example, a twin-shaft mixer 40 is used to mix a polyolefin resin 12 containing plant fibers and a cyclic compound 20 at a screw speed of 250 rpm and a barrel temperature of 200 degrees Celsius to obtain a resin composition 30. The resin composition 30 is injected into a molding machine 41 and subjected to a molding step of injection molding at high temperature to form a resin molded body 31.

[0056] (Modification 2 of the first embodiment)

[0057] A variation 2 of the method for manufacturing the resin composition of the first embodiment will be described. For example... Figure 4 As shown, in a modified example 2 of the method for manufacturing the resin composition of this embodiment, for example, a twin-shaft mixer 40 is used to mix a polyolefin resin 12 containing plant fibers and a cyclic compound 20 at a screw speed of 250 rpm and a barrel temperature of 200 degrees Celsius to obtain granular resin particles 32.

[0058] (Second Implementation)

[0059] The second embodiment of the present invention will now be described. It should be noted that descriptions of the same manufacturing method as that of the resin composition in the first embodiment of the present invention are appropriately omitted.

[0060] like Figure 5As shown, in the method for manufacturing the resin composition of the second embodiment, plant fiber 10, polyolefin resin 11, cyclic compound 20, and polyamine 50 having at least one amine selected from primary and secondary amines are mixed in a biaxial mixer 40 at a screw speed of 250 rpm and a barrel temperature of 200 degrees Celsius to obtain resin composition 30. Resin composition 30 is injected into a molding machine 41 and injection molded at a high temperature to obtain resin molded body 31. That is, the method for manufacturing the resin composition of the second embodiment differs from the first embodiment in that it contains polyamines. It should be noted that in the second embodiment, polyoxazoline may be used instead of polyamines, or a mixture of polyamines and polyoxazoline may be contained.

[0061] Polyamines or polyoxazolines react with carboxylic acids and aldehydes that constitute corrosive gas 10A, produced when plant fibers 10 are thermally decomposed. Therefore, by containing polyamines or polyoxazolines, the corrosion of the mold can be further inhibited.

[0062] For example, carboxylic acids react with primary and / or secondary amines to form carboxylate amides. As an example, the reaction mechanism of carboxylic acids with primary amines is shown below.

[0063] (Chemical Formula 9)

[0064] Additionally, aldehydes can react with primary and / or secondary amines to form imines. As an example, the reaction mechanism of aldehydes with primary amines is shown below.

[0065] (Chemical Formula 10)

[0066] The corrosive gas 10A produced by hemicellulose or lignin contains a high proportion of long-chain fatty acids. These long-chain fatty acids, after reacting with polyamines or polyoxazolines, are oriented along the flow direction during injection molding. Since most of the long-chain fatty acids are hydrophobic hydrocarbon groups, the resin composition exhibits a waxy effect on its surface, resulting in high release properties from the hydrophobic mold.

[0067] As the polyamine 50, in addition to aliphatic amines such as polyallylamine, polyethyleneimine, polypropyleneimine, polybuteneimine, and polyisopropyleneimine, aromatic amines with alkyl groups, such as p-hexylaniline and 2-hexyl-5-aminothiophene, can also be used. It should be noted that when the boiling point of the polyamine is low, there is a concern that evaporation may occur when it is compounded with plant fiber 10 and polyolefin resin 11. Therefore, aliphatic or aromatic amines with a boiling point or decomposition temperature of 250°C or higher are preferred.

[0068] The weight-average molecular weight (Mw) of polyamine 50 and polyoxazoline is preferably 300 to 100,000, more preferably 10,000 to 100,000, and even more preferably 10,000 to 70,000. When the weight-average molecular weight of the polyamine and polyoxazoline is less than 300, the polyamine will volatilize due to the heat generated during compounding with plant fiber 10 and polyolefin resin 11. Therefore, a waxy effect on the surface of the resin composition will not occur, and mold release properties will be reduced. Furthermore, when the weight-average molecular weight is low, the polyamine is highly toxic, requiring careful handling. Therefore, workability during manufacturing is reduced. When the weight-average molecular weight of the polyamine and polyoxazoline is greater than 100,000, the resin composition becomes highly viscous, making thorough compounding difficult. Therefore, the reaction of primary and / or secondary amines with corrosive gases becomes incomplete, and a large amount of corrosive gas remains unreacted. Therefore, the suppression of corrosion of the mold used during injection molding becomes insufficient. Furthermore, when the weight-average molecular weight of polyamines and polyoxazolines is greater than 100,000, the proportion of tertiary amines per unit mass increases, while the proportion of primary and / or secondary amines reacting with corrosive gas 10A decreases. Therefore, corrosion suppression of the mold used during injection molding becomes insufficient.

[0069] The amount of polyamine 50 or polyoxazoline relative to plant fiber 10 is preferably 0.05 to 3.00% by weight. Setting the amount of polyamine or polyoxazoline to 0.05% by weight or more can further improve the inhibition of mold corrosion. However, if the amount of polyamine or polyoxazoline exceeds 3.00% by weight, the amount of polyamine may be excessive relative to the corrosive gas 10A generated by plant fiber 10. Excess polyamine or polyoxazoline reacts with the hydrophobic component of the resin composition that can exert the effect of release properties from the hydrophobic mold, resulting in a decrease in the release properties of the resin composition from the mold.

[0070] The second embodiment will now be described in more detail with reference to modified examples. It should be noted that the present invention is not limited to these modified examples.

[0071] (Modification 1 of the second embodiment)

[0072] A variation 1 of the method for manufacturing the resin composition according to the second embodiment will be described. In variation 1 of the method for manufacturing the resin composition according to this embodiment, for example, a twin-shaft mixer 40 is used to mix a polyolefin resin 12 containing plant fibers, a cyclic compound 20, and a polyamine 50 having at least one of a primary amine and a secondary amine, at a screw speed of 250 rpm and a barrel temperature of 200 degrees Celsius to obtain a resin composition 30. The resin composition 30 is injected into a molding machine 41 and injection molded at a high temperature to obtain a resin molded body 31.

[0073] (Modification 2 of the second embodiment)

[0074] A variation 2 of the method for manufacturing the resin composition according to the second embodiment will be described. In variation 2 of the method for manufacturing the resin composition according to this embodiment, for example, a twin-shaft mixer 40 is used to mix a polyolefin resin 12 containing plant fibers, a cyclic compound 20, and a polyamine 50 having at least one of a primary amine and a secondary amine at a screw speed of 250 rpm and a barrel temperature of 200 degrees Celsius to obtain resin particles 32.

[0075] The present invention will be further described in detail below with reference to embodiments and comparative examples. It should be noted that the present invention is not limited to these embodiments.

[0076] (Example 1)

[0077] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd. (Japan)) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the following cyclic compound B-1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 0.10% relative to the wood flour.

[0078] (Chemical Formula 11)

[0079] These materials were mixed using a biaxial mixing apparatus (TECHNOVEL, KZW25TW-60MG-NH(-600)) at, for example, a screw speed of 250 rpm and a barrel temperature of 200°C to obtain a resin composition. The obtained resin composition was then dried in a hot air dryer at 100°C for 2 hours. Next, an injection molding machine equipped with an ISO physical property test piece mold (J100ADS-100U, Nippon Steel Co., Ltd.) was used with the following conditions set: barrel temperature 300°C, mold temperature 80°C, injection pressure 50 MPa (gauge pressure), injection speed 200 mm / sec, and injection time / cooling time = 20 sec / 20 sec. This yielded a strip-shaped test piece (resin molded body) of Example 1 with a length of 80.0 mm, a width of 10.0 mm, and a thickness of 4.0 mm.

[0080] (Example 2)

[0081] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 5.00% relative to the wood flour. Using these materials, and employing the same method as in Example 1, the strip-shaped test piece of Example 2 was obtained.

[0082] (Example 3)

[0083] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the following cyclic compound B-2 was used as a carbodiimide, and this cyclic compound B-2 was used in an amount of 0.10% relative to the wood flour. Using these materials, the strip-shaped test piece of Example 3 was obtained using the same method as in Example 1.

[0084] (Chemical Formula 12)

[0085] (Example 4)

[0086] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-2 as in Example 3 was used as a carbodiimide, and this cyclic compound B-2 was used in an amount of 5.00% relative to the wood flour. Using these materials, and employing the same method as in Example 1, the strip-shaped test piece of Example 4 was obtained.

[0087] (Example 5)

[0088] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the following cyclic compound B-3 was used as a carbodiimide, and this cyclic compound B-3 was used in an amount of 0.10% relative to the wood flour. Using these materials, and employing the same method as in Example 1, the strip-shaped test piece of Example 5 was obtained.

[0089] (Chemical Formula 13)

[0090] (Example 6)

[0091] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-3 as in Example 5 was used as a carbodiimide, and this cyclic compound B-3 was used in an amount of 5.00% relative to the wood flour. Using these materials, and employing the same method as in Example 1, the strip-shaped test piece of Example 6 was obtained.

[0092] (Example 7)

[0093] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the following cyclic compound B-4 was used as a carbodiimide, and this cyclic compound B-4 was used in an amount of 0.10% relative to the wood flour. Using these materials, and employing the same method as in Example 1, the strip-shaped test piece of Example 7 was obtained.

[0094] (Chemical Formula 14)

[0095] (Example 8)

[0096] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-4 as in Example 7 was used as a carbodiimide, and this cyclic compound B-4 was used in an amount of 5.00% relative to the wood flour. Using these materials, and employing the same method as in Example 1, the strip-shaped test piece of Example 8 was obtained.

[0097] (Example 9)

[0098] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 0.05% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 0.05% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 9 was obtained.

[0099] (Example 10)

[0100] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 0.05% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 3.00% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 10 was obtained.

[0101] (Example 11)

[0102] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 3.00% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 0.05% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 11 was obtained.

[0103] (Example 12)

[0104] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from hardwood trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 3.00% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 3.00% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 12 was obtained.

[0105] (Example 13)

[0106] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 0.05% relative to the wood flour. Furthermore, polyethyleneimine C-2 (trade name: EPOMIN(R), product number: P-1000, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 70,000 was used as a polyamine, and this polyethyleneimine C-2 was used in an amount of 0.05% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 13 was obtained.

[0107] (Example 14)

[0108] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 0.05% relative to the wood flour. Furthermore, polyethyleneimine C-2 (trade name: EPOMIN(R), product number: P-1000, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 70,000 was used as a polyamine, and this polyethyleneimine C-2 was used in an amount of 3.00% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 14 was obtained.

[0109] (Example 15)

[0110] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 3.00% relative to the wood flour. Furthermore, as a polyamine, polyethyleneimine C-2 (trade name: EPOMIN(R), product number: P-1000, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 70,000 was used, and this polyethyleneimine C-2 was used in an amount of 0.05% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 13 was obtained.

[0111] (Example 16)

[0112] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from hardwood trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 3.00% relative to the wood flour. Furthermore, polyethyleneimine C-2 (trade name: EPOMIN(R), product number: P-1000, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 70,000 was used as a polyamine, and this polyethyleneimine C-2 was used in an amount of 3.00% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 16 was obtained.

[0113] (Example 17)

[0114] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 0.05% relative to the wood flour. Furthermore, polyoxazoline C-3 (trade name: EPOCROS(R), product number: WS-700, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 40,000 was used as the polyoxazoline, and this polyoxazoline C-3 was used in an amount of 0.50% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 17 was obtained.

[0115] (Example 18)

[0116] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 0.05% relative to the wood flour. Furthermore, polyoxazoline C-3 (trade name: EPOCROS(R), product number: WS-700, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 40,000 was used as the polyoxazoline, and this polyoxazoline C-3 was used in an amount of 3.00% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 18 was obtained.

[0117] (Example 19)

[0118] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 3.00% relative to the wood flour. Furthermore, polyoxazoline C-3 (trade name: EPOCROS(R), product number: WS-700, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 40,000 was used as the polyoxazoline, and this polyoxazoline C-3 was used in an amount of 0.05% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 19 was obtained.

[0119] (Example 20)

[0120] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 3.00% relative to the wood flour. Furthermore, polyoxazoline C-3 (trade name: EPOCROS(R), product number: WS-700, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 40,000 was used as the polyoxazoline, and this polyoxazoline C-3 was used in an amount of 3.00% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 20 was obtained.

[0121] (Example 21)

[0122] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 0.05% relative to the wood flour. Furthermore, polyoxazoline C-4 (trade name: EPOCROS(R), product number: WS-500, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 70,000 was used as the polyoxazoline, and this polyoxazoline C-4 was used in an amount of 0.50% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 21 was obtained.

[0123] (Example 22)

[0124] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 0.05% relative to the wood flour. Furthermore, polyoxazoline C-4 (trade name: EPOCROS(R), product number: WS-500, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 70,000 was used as the polyoxazoline, and this polyoxazoline C-4 was used in an amount of 3.00% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 22 was obtained.

[0125] (Example 23)

[0126] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 3.00% relative to the wood flour. Furthermore, polyoxazoline C-4 (trade name: EPOCROS(R), product number: WS-500, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 70,000 was used as the polyoxazoline, and this polyoxazoline C-4 was used in an amount of 0.05% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 23 was obtained.

[0127] (Example 24)

[0128] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 3.00% relative to the wood flour. Furthermore, polyoxazoline C-4 (trade name: EPOCROS(R), product number: WS-500, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 70,000 was used as the polyoxazoline, and this polyoxazoline C-4 was used in an amount of 3.00% relative to the wood flour. Using these materials, and employing the same method as in Example 1, strip-shaped test pieces of Example 24 were obtained.

[0129] (Example 25)

[0130] As a polyolefin resin incorporating plant fibers, resin material A-2 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% coniferous wood flour and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 0.05% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 0.05% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 25 was obtained.

[0131] (Example 26)

[0132] As a polyolefin resin incorporating plant fibers, resin material A-2 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% coniferous wood flour and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this compound B-1 was used in an amount of 0.05% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 3.00% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 26 was obtained.

[0133] (Example 27)

[0134] As a polyolefin resin incorporating plant fibers, resin material A-2 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% coniferous wood flour and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 3.00% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 0.05% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 27 was obtained.

[0135] (Example 28)

[0136] As a polyolefin resin incorporating plant fibers, resin material A-2 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% coniferous wood flour and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 3.00% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 3.00% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 28 was obtained.

[0137] (Example 29)

[0138] As a polyolefin resin incorporating plant fibers, resin material A-2 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% coniferous wood flour and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 0.50% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 0.50% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 29 was obtained.

[0139] (Example 30)

[0140] As a polyolefin resin incorporating plant fibers, resin material A-2 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% coniferous wood flour and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 0.50% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 1.50% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 30 was obtained.

[0141] (Example 31)

[0142] As a polyolefin resin incorporating plant fibers, resin material A-2 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% coniferous wood flour and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 1.50% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 0.50% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 31 was obtained.

[0143] (Example 32)

[0144] As a polyolefin resin incorporating plant fibers, resin material A-2 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% coniferous wood flour and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 1.50% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight-average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 1.50% relative to the wood flour. Using these materials, and employing the same method as in Example 1, a strip-shaped test piece of Example 32 was obtained.

[0145] (Example 33)

[0146] As a polyolefin resin incorporating plant fibers, resin material A-2 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from coniferous trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 0.05% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 0.025% relative to the wood flour. Polyoxazoline C-3 (trade name: EPOCROS(R), product number: WS-700, manufactured by Nippon Shokubai Co., Ltd.) with a weight average molecular weight of 40,000 was used as a polyoxazoline, and this polyoxazoline C-3 was used in an amount of 0.025% relative to the wood flour. Using these materials and employing the same method as in Example 1, the strip-shaped test piece of Example 33 was obtained.

[0147] (Example 34)

[0148] As a polyolefin resin incorporating plant fibers, resin material A-2 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from coniferous trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 0.05% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 1.50% relative to the wood flour. Polyoxazoline C-3 (trade name: EPOCROS(R), product number: WS-700, manufactured by Nippon Shokubai Co., Ltd.) with a weight average molecular weight of 40,000 was used as a polyoxazoline, and this polyoxazoline C-3 was used in an amount of 1.50% relative to the wood flour. Using these materials and employing the same method as in Example 1, the strip-shaped test piece of Example 34 was obtained.

[0149] (Example 35)

[0150] As a polyolefin resin incorporating plant fibers, resin material A-2 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from coniferous trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 3.00% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 0.025% relative to the wood flour. Polyoxazoline C-3 (trade name: EPOCROS(R), product number: WS-700, manufactured by Nippon Shokubai Co., Ltd.) with a weight average molecular weight of 40,000 was used as a polyoxazoline, and this polyoxazoline C-3 was used in an amount of 0.025% relative to the wood flour. Using these materials and employing the same method as in Example 1, the strip-shaped test piece of Example 35 was obtained.

[0151] (Example 36)

[0152] As a polyolefin resin incorporating plant fibers, resin material A-2 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from coniferous trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 3.00% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 1.50% relative to the wood flour. Polyoxazoline C-3 (trade name: EPOCROS(R), product number: WS-700, manufactured by Nippon Shokubai Co., Ltd.) with a weight average molecular weight of 40,000 was used as a polyoxazoline, and this polyoxazoline C-3 was used in an amount of 1.50% relative to the wood flour. Using these materials and employing the same method as in Example 1, the strip-shaped test piece of Example 36 was obtained.

[0153] (Example 37)

[0154] As a polyolefin resin incorporating plant fibers, resin material A-2 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from coniferous trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 0.50% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 0.025% relative to the wood flour. Polyoxazoline C-3 (trade name: EPOCROS(R), product number: WS-700, manufactured by Nippon Shokubai Co., Ltd.) with a weight average molecular weight of 40,000 was used as a polyoxazoline, and this polyoxazoline C-3 was used in an amount of 0.025% relative to the wood flour. Using these materials and employing the same method as in Example 1, the strip-shaped test piece of Example 37 was obtained.

[0155] (Example 38)

[0156] As a polyolefin resin incorporating plant fibers, resin material A-2 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from coniferous trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 0.50% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 0.75% relative to the wood flour. Polyoxazoline C-3 (trade name: EPOCROS(R), product number: WS-700, manufactured by Nippon Shokubai Co., Ltd.) with a weight average molecular weight of 40,000 was used as a polyoxazoline, and this polyoxazoline C-3 was used in an amount of 0.75% relative to the wood flour. Using these materials and employing the same method as in Example 1, the strip-shaped test piece of Example 38 was obtained.

[0157] (Example 39)

[0158] As a polyolefin resin incorporating plant fibers, resin material A-2 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from coniferous trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 1.50% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 0.025% relative to the wood flour. Polyoxazoline C-3 (trade name: EPOCROS(R), product number: WS-700, manufactured by Nippon Shokubai Co., Ltd.) with a weight average molecular weight of 40,000 was used as a polyoxazoline, and this polyoxazoline C-3 was used in an amount of 0.025% relative to the wood flour. Using these materials and employing the same method as in Example 1, the strip-shaped test piece of Example 39 was obtained.

[0159] (Example 40)

[0160] As a polyolefin resin incorporating plant fibers, resin material A-2 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from coniferous trees and 45% polypropylene (PP). Additionally, the same cyclic compound B-1 as in Example 1 was used as a carbodiimide, and this cyclic compound B-1 was used in an amount of 1.50% relative to the wood flour. Furthermore, polyethyleneimine C-1 (trade name: EPOMIN(R), product number: SP-200, manufactured by Nippon Shokubai Co., Ltd.) with a weight average molecular weight of 10,000 was used as a polyamine, and this polyethyleneimine C-1 was used in an amount of 0.75% relative to the wood flour. Polyoxazoline C-3 (trade name: EPOCROS(R), product number: WS-700, manufactured by Nippon Shokubai Co., Ltd.) with a weight average molecular weight of 40,000 was used, and this polyoxazoline C-3 was used in an amount of 0.75% relative to the wood flour. Using these materials and employing the same method as in Example 1, the strip-shaped test piece of Example 40 was obtained.

[0161] (Comparative Example 1)

[0162] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, N,N'-dicyclohexylcarbodiimide B-5 was used as the carbodiimide, and this N,N'-dicyclohexylcarbodiimide B-5 was used in an amount of 0.10% relative to the wood flour. Using these materials, a strip-shaped test piece of Comparative Example 1 was obtained using the same method as in Example 1.

[0163] (Comparative Example 2)

[0164] As a polyolefin resin incorporating plant fibers, resin material A-1 (manufactured by i-compology Co., Ltd.) was used, consisting of 55% wood flour derived from broadleaf trees and 45% polypropylene (PP). Additionally, N,N'-dicyclohexylcarbodiimide B-5 was used as the carbodiimide, and this N,N'-dicyclohexylcarbodiimide B-5 was used in an amount of 5.00% relative to the wood flour. Using these materials, a strip-shaped test piece of Comparative Example 2 was obtained using the same method as in Example 1.

[0165] (Evaluation of isocyanate gas production)

[0166] The test pieces of Examples 1-40 and Comparative Examples 1-2 were analyzed using thermal decomposition GC / MS. A GC-MS-QP2020 NX manufactured by Shimadzu Corporation was used as the GC / MS, an EGA / PY-3030D manufactured by Frontier Lab. Ltd. was used as the sample preparation device, and a UA+5 manufactured by Frontier Lab. Ltd. was used as the column for analysis. In the evaluation of isocyanate gas generation, five levels from A to E were assigned based on the amount of isocyanate gas detected by thermal decomposition GC / MS. In this evaluation, no isocyanate gas was rated as A; isocyanate gas was detected at less than 20 ppm as B; isocyanate gas was detected at 20 ppm or more but less than 50 ppm as C; isocyanate gas was detected at 50 ppm or more but less than 100 ppm as D; and isocyanate gas was detected at 100 ppm or more as E. Figure 6 The evaluation results of isocyanate gas production in Examples 1-40 and Comparative Examples 1-2 are summarized and shown.

[0167] (Evaluation of demolding performance)

[0168] The contact area between the test pieces and the mold after the ejection step of injection molding in Examples 1-40 and Comparative Examples 1-2 was visually confirmed, and the demolding performance was evaluated using five stages, A to E. In this evaluation, A was rated as 100% separation of the test piece surface from the mold; B was rated as 70% to less than 100% separation; C was rated as 50% to less than 70% separation; D was rated as 20% to less than 50% separation; and E was rated as less than 20% separation. Figure 6 The evaluation results of the demolding properties of Examples 1 to 40 and Comparative Examples 1 to 2 are summarized and shown in the table.

[0169] (Evaluation of corrosivity)

[0170] One hundred test pieces each of Examples 1 to 40 and Comparative Examples 1 to 2 were consecutively prepared. The surface condition of the mold was checked after each test piece was prepared, and the corrosion was evaluated into five levels, A to E, based on the number of test pieces prepared until the mold surface became contaminated. Mold surface contamination refers to the presence of rust on the mold surface. In this evaluation, a level of no mold surface contamination was assessed as A; a level of contamination was assessed as B; a level of contamination as C; a level of contamination as D; and a level of contamination as E. Figure 6 The results of the evaluation of the corrosivity of Examples 1 to 40 and Comparative Examples 1 to 2 are summarized and shown.

[0171] (Evaluation of heat resistance)

[0172] According to ISO-75, the load deflection temperatures of the test pieces from Examples 1-40 and Comparative Examples 1-2 were determined under conditions of a load of 0.45 MPa and a heating rate of 2 °C / min. Three measurements were performed for each example, and the heat resistance was evaluated using five grades from A to E, based on the average value. A load deflection temperature of 140 °C or higher was rated A; 130 °C or higher but less than 140 °C was rated B; 120 °C or higher but less than 130 °C was rated C; 100 °C or higher but less than 120 °C was rated D; and less than 100 °C was rated E. Figure 6 The results of the heat resistance evaluation of Examples 1-40 and Comparative Examples 1-2 are summarized and shown.

[0173] Depend on Figure 6 It is evident that, according to Examples 1-40, corrosion of the mold during injection molding can be suppressed, and the generation of isocyanate gas can be prevented. The resin compositions of Examples 1-40 were prepared by mixing at least one of plant fiber, polyolefin resin, first cyclic compound, second cyclic compound, third cyclic compound, and fourth cyclic compound.

[0174] The results from Examples 9-40 clearly demonstrate that, in the presence of polyamines or polyoxazoline, no contamination of the mold surface was detected at least when 30 test pieces were prepared, thus ensuring superior corrosion resistance. Furthermore, both the release properties and heat resistance evaluations were rated B or A, indicating that the presence of polyamines or polyoxazoline ensures superior release properties and heat resistance.

[0175] As can be clearly seen from the results of Examples 25-40, when wood flour derived from coniferous trees is used as the plant fiber and polyethyleneimine with a weight-average molecular weight of 10,000 is used as the polyamine, the load flexural temperature is above 140°C in the evaluation of heat resistance, thus ensuring superior heat resistance.

[0176] In contrast, according to Comparative Examples 1 and 2, the generation of isocyanate gas could not be suppressed. The resin compositions in Comparative Examples 1 and 2 were obtained by compounding plant fibers, polyolefin resins, and N,N'-dicyclohexylcarbodiimide, wherein the N,N'-dicyclohexylcarbodiimide is a carbodiimide in which the first nitrogen and the second nitrogen are bonded by a bonding group, and unsubstituted aromatic carbodiimides are bonded to both the first and second nitrogen. Furthermore, in the evaluation of mold release properties, the separation of the test piece surface from the mold was less than 20%, therefore, sufficient mold release properties during injection molding could not be ensured.

[0177] The above-mentioned method for manufacturing the resin composition, resin molded body, and resin particles according to the present invention can suppress the corrosion of the mold during injection molding and can suppress the generation of isocyanate gas.

[0178] Explanation of reference numerals in the attached figures

[0179] 10: Plant fiber; 10A: Corrosive gas; 11: Polyolefin resin; 12: Polyolefin resin formulated with plant fiber; 20: Cyclic compound; 30: Resin composition; 31: Resin molded body; 32: Resin particles; 40: Biaxial mixer; 41: Molding machine; 50: Polyamine.

Claims

1. A method for producing a resin composition, comprising a step of mixing a plant fiber, a polyolefin-based resin, and at least one of a first cyclic compound, a second cyclic compound, a third cyclic compound, and a fourth cyclic compound to obtain a resin composition, The method for producing the resin composition is characterized in that The first ring compound is a ring compound having a main ring structure and two or more first sub-ring structures, wherein, the main ring structure contains a carbodiimide bonded by a bonding group between a first nitrogen and a second nitrogen, and the two or more first sub ring structures are fused to a part of the main ring structure; the second cyclic compound is a cyclic compound having the main ring structure and two or more second sub ring structures extending from the main ring structure as substituents; the third cyclic compound has the main ring structure, the first sub ring structure fused to a part of the main ring structure, and second sub ring structures respectively extending from the first sub ring structure as substituents; the fourth cyclic compound is a cyclic compound having the main ring structure, the first sub ring structure fused to a part of the main ring structure, and a second sub ring structure fused to a part of the first sub ring structure.

2. The method for producing a resin composition according to claim 1, characterized by comprising the following steps: mixing the plant fiber, the polyolefin-based resin, at least one of the first cyclic compound, the second cyclic compound, the third cyclic compound, and the fourth cyclic compound, and at least one of a polyamine having at least one of a primary amine and a secondary amine, and a polyoxazoline to obtain a resin composition.

3. The method of producing a resin composition according to claim 1 or 2, characterized by, The plant fiber is wood powder derived from a coniferous tree.

4. A method for producing a resin-molded body, comprising a step of mixing a plant fiber, a polyolefin-based resin, and at least one of a first cyclic compound, a second cyclic compound, a third cyclic compound, and a fourth cyclic compound to obtain a resin composition. and, a molding step of molding the resin composition into a member of an apparatus having a heat source with a temperature of 300°C or lower, The method for producing the resin molding is characterized in that the first cyclic compound is a cyclic compound having a main ring structure and two or more first sub ring structures, wherein the main ring structure contains a carbodiimide bonded by a bonding group between a first nitrogen and a second nitrogen, and the two or more first sub ring structures are fused to a part of the main ring structure; the second cyclic compound is a cyclic compound having the main ring structure and two or more second sub ring structures extending from the main ring structure as substituents; the third cyclic compound has the main ring structure, the first sub ring structure fused to a part of the main ring structure, and second sub ring structures respectively extending from the first sub ring structure as substituents; the fourth cyclic compound is a cyclic compound having the main ring structure, the first sub ring structure fused to a part of the main ring structure, and a second sub ring structure fused to a part of the first sub ring structure.

5. The method for producing a resin-molded body according to claim 4, characterized by The member is a housing or a bracket of a vehicle lamp.

6. A method for producing resin particles, comprising a step of mixing a plant fiber, a polyolefin-based resin, and at least one compound selected from a first cyclic compound, a second cyclic compound, a third cyclic compound, and a fourth cyclic compound to obtain a resin composition. and, a molding step of molding the resin composition into a granular shape, The method for producing the resin particle is characterized in that The first ring compound is a ring compound having a main ring structure and two or more first sub ring structures, wherein the main ring structure contains a carbodiimide formed by bonding a first nitrogen and a second nitrogen by a bonding group, and the two or more first sub ring structures are fused to a part of the main ring structure; The second ring compound is a ring compound having the main ring structure and two or more second sub ring structures extending from the main ring structure as substituents; The third ring compound has the main ring structure, the first sub ring structure fused to a part of the main ring structure, and the second sub ring structure extending from the first sub ring structure as a substituent, respectively; The fourth ring compound is a ring compound having the main ring structure, the first sub ring structure fused to a part of the main ring structure, and the second sub ring structure fused to a part of the first sub ring structure.

7. The method of manufacturing resin particles according to claim 6, further comprising the step of: mixing at least one of the plant fiber, the polyolefin-based resin, the first ring compound, the second ring compound, the third ring compound, and the fourth ring compound, and at least one of a polyamine having at least one of a primary amine and a secondary amine, and a polyoxazoline to obtain a resin composition. ​

Images