Low odor composition, low VOC resin composition, method for producing same, and regenerated material

Abstract

The present invention is a low-odor composition which is used as a fiber-reinforced resin material and which is obtained by kneading lignocellulosic fibers containing lignin, a resin, and an odor-reducing material. The odor-reducing material is one or both of activated carbon and a basic compound. The lignocellulosic fibers have a lignin component content of 5-50% by mass (inclusive). In addition, the present invention is a low-VOC resin composition which is used as a fiber-reinforced resin material and which is obtained by kneading lignocellulosic fibers containing hemicellulose, a resin, and a VOC-reducing material. The VOC reducing material contains a hydrazide compound. The VOC-reducing material preferably contains a hydrazide compound and a urea compound.

Description

Technical Field

[0001] The present invention relates to a low-odor composition, a low-VOC resin composition, and methods for producing the same and recycled materials. Background Art

[0002] Lignocellulose resources derived from wood and / or non-wood plants are recognized as carbon-neutral materials that store carbon dioxide during plant growth and do not emit excess carbon dioxide when used and / or discarded.

[0003] Lignocellulosic resources obtained from wood and / or non-wood plants are composed of lignocellulosic fibers. Lignocellulosic fibers are obtained by subjecting lignocellulosic resources to mechanical, thermomechanical, chemical, chemomechanical, or chemothermomechanical treatments to soften, destroy, loosen, or micronize the adhesive-bound interlayer of fibers. The lignocellulosic fibers thus obtained are primarily used as pulp for paper and / or fiber for fiberboard. This is because lignocellulosic fibers are lightweight, strong, highly resilient, recyclable, and inexpensive.

[0004] To address recent environmental issues, particularly global warming, the use of lignocellulosic fibers is highly anticipated as an alternative to talc, glass fiber, carbon fiber, synthetic resin fiber, mineral fiber, and metal fiber, which have been used as resin reinforcements. Replacing these non-renewable materials with lignocellulosic fibers offers advantages such as material weight reduction, improved Life Cycle Assessment (LCA), and / or cost reduction. Consequently, the use of lignocellulosic fibers is attracting attention in the transportation equipment manufacturing industry, particularly the automotive industry.

[0005] However, lignocellulosic fibers are primarily composed of three components: cellulose, hemicellulose, and lignin. Hemicellulose and / or lignin are less stable to heat than cellulose, and therefore undergo thermal modification during mixing with thermoplastic resins and molding. Lignin, in particular, is prone to causing problems such as a burnt odor (hereinafter referred to as "burnt odor"). It should be noted that burnt odor refers to the characteristic burnt, charred, or smoke-like odor produced by wood in the early stages of carbonization, primarily consisting of low-molecular aromatic compounds, such as phenols and / or their analogs, such as phenolic aldehydes, phenolic ketones, and phenolic alcohols.

[0006] Therefore, when mixing lignocellulose fibers with thermoplastic resins to produce fiber-resin compositions and / or molded products, in order to prevent the generation of burnt odors, expensive cellulose materials such as so-called dissolved cellulose (high-purity cellulose) with high purity and / or chemically modified cellulose with high thermal stability have to be used, resulting in a problem of increased costs.

[0007] Furthermore, hemicellulose has a low thermal decomposition point and is easily oxidized, modified, and decomposed by heat during mixing with thermoplastic resins and / or molding. Consequently, it easily releases volatile organic compounds (VOCs) such as carboxylic acids and / or aldehydes. Formaldehyde and acetaldehyde are chemical substances designated by the Ministry of Health, Labour, and Welfare as indoor airborne substances, and therefore have published indoor concentration guideline values. Construction companies and / or automobile manufacturers set baseline emission limits based on applications such as building and / or automobile interiors. Against this backdrop, in order to market resins containing lignocellulosic fibers, it is necessary to meet these VOC emission guideline values.

[0008] Therefore, when mixing lignocellulose fibers with thermoplastic resins to produce fiber-resin compositions and / or molded products, from the perspective of reducing VOC emissions, expensive cellulose materials such as so-called dissolved cellulose (high-purity cellulose) with high purity and / or chemically modified cellulose with high thermal stability have to be used, resulting in a problem of increased costs.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: US4833181A

[0012] Patent Document 2: Japanese Patent Application Laid-Open No. 11-293034

[0013] Patent Document 3: Japanese Patent Application Laid-Open No. 2000-319477

[0014] Patent Document 4: Japanese Patent Application Laid-Open No. 2002-179830

[0015] Patent Document 5: US2018311058A1

[0016] Patent Document 6: EP2261417A1

[0017] Patent Document 7: Japanese Patent Application Laid-Open No. 2006-28366

[0018] Patent Document 8: US2018362405A1

[0019] Patent Document 9: Japanese Patent Application Laid-Open No. 2000-186212

[0020] Patent Document 10: Japanese Patent Application Laid-Open No. 2020-196797

[0021] Patent Document 11: EP3910014A1

[0022] Patent Document 12: US2022275196A1

[0023] Non-patent literature

[0024] Non-patent literature 1: Emission of possible odorous low molecular weight compounds in recycled biofiber / polypropylene composites monitored by head-space SPME-GC-MS, Polymer Degradation and Stability90 (2005) 555-562, Espert etal.

[0025] Non-Patent Document 2: Japanese Automotive Standards Organization (JASO) M 902, "Automobile Parts - Interior Materials - Volatile Organic Compound (VOC) Emission Measurement Method" (2018) Summary of the Invention

[0026] Under the premise of using lignocellulosic fibers containing lignin as raw materials and using general resin processing equipment while solving the above-mentioned problems, it is preferable to develop technologies for physically and chemically reducing the modification and / or decomposition of lignin that causes burnt odor, and / or technologies for reducing the generated burnt odor by releasing it to the outside of the system during the processing step, technologies for physically and chemically reducing the generated burnt odor, etc., both in terms of practicality and cost.

[0027] Patent Document 1 discloses a technology related to a low-odor resin composition comprising a thermoplastic resin, a plant fiber primarily composed of fibrillated cellulose, and activated carbon. The document states that plant fibers primarily composed of fibrillated cellulose include those obtained by defibration of waste paper, paper scraps, and the like. However, since waste paper, paper scraps, and the like contain almost no lignin or hemicellulose, which can cause odors, particularly burnt odors, their odor is typically quite low. The effect of using lignocellulosic fibers containing lignin and / or hemicellulose instead of plant fibers primarily composed of fibrillated cellulose is unclear. Furthermore, the document does not disclose the temperature conditions used when mixing the resin, so the possibility of odor generation due to improper mixing conditions cannot be ruled out.

[0028] Patent Document 2 discloses a deodorizing composition containing a resin, an alkaline compound, hydrated silicic acid, and dihydrazide for aldehyde and / or ammonia odors. However, this composition is intended to absorb external odors from the resin material after kneading and forming, not to reduce internal odors generated during kneading and / or forming. Therefore, its effectiveness against internal odors is unclear. Furthermore, there is no description of the composition's effectiveness against burnt odors from lignocellulosic fibers, making its effectiveness unclear.

[0029] Patent Document 3 discloses a low-acrylic-odor resin composition containing a soft acrylic resin and activated carbon. However, acrylic odor and the burning odor from lignocellulosic fibers are caused by different substances and / or target substances, and therefore the effect of acrylic odor on the burning odor from lignocellulosic fibers is unknown.

[0030] Patent Document 4 discloses a deodorizing material comprising a foamed resin containing activated carbon. In addition, Patent Document 5 discloses a deodorizing material for aldehyde odors comprising a resin and hydrazine. In addition, Patent Document 6 discloses a fibrous deodorizing material obtained by kneading and fiberizing a component composed of inorganic particles and amines and attaching the component to fibers. However, the deodorizing materials described in Patent Documents 4 to 6 are intended to have the effect of adsorbing odors from the outside by the resin material after kneading and forming, and are not intended to reduce odors from the inside generated during kneading and / or forming. Therefore, the effect on odors generated internally is unclear. Furthermore, Patent Documents 4 to 6 do not describe the effect on burnt odors from lignocellulosic fibers. Therefore, the effect on burnt odors from lignocellulosic fibers is unclear.

[0031] In addition, regarding VOCs, it is preferable to develop technologies for physically and chemically reducing the modification and / or decomposition of hemicellulose, which is the cause of VOCs, and / or technologies for reducing the generated VOCs by releasing them outside the system during the processing steps, technologies for physically and chemically reducing the generated VOCs, etc., both from a practical and cost perspective.

[0032] Patent Document 7 discloses a formaldehyde scavenger, which is applied to a wood-based material such as particleboard containing a formaldehyde-based adhesive and comprises a mixed aqueous solution of a hydrazine compound and a carboxylic acid. However, the cost of applying and / or spraying such an aqueous solution onto a resin molded article during the manufacturing process is high, and there is also the issue of impaired appearance due to coating and / or spray marks on the surface of the product. Furthermore, the residual effect of the formaldehyde scavenger added internally during resin kneading and exposure to high temperatures of around 200°C, such as resin kneading and / or molding, and / or its ability to reduce acetaldehyde, as well as its aldehyde-reducing effect at high temperatures (e.g., 65°C) where release significantly increases compared to room temperature, remain uncertain, particularly regarding aldehydes derived from lignocellulose.

[0033] Patent Document 8 discloses a method for producing a dry nanocellulose-reinforced resin and a reinforced resin composition comprising cellulose fibers, a hydrazine compound as a defibrillating agent for the cellulose fibers, and a resin. However, this document describes the hydrazine compound as a defibrillating agent for defibrillating relatively coarse cellulose fiber bundles into nanoscale cellulose molecular bundles. It does not describe its use for VOC reduction, nor does it suggest its use.

[0034] Patent Document 9 discloses a deodorant composition containing a binder, a hydrazide compound, and an imidazole compound. However, the residual effect of this deodorant composition after exposure to high temperatures near 200°C, such as during resin kneading and / or injection / extrusion molding, and / or its ability to reduce acetaldehyde, as well as its ability to reduce aldehyde at elevated temperatures, such as 65°C, where release significantly increases compared to room temperature, remain uncertain. Furthermore, the embodiments described only demonstrate effects achieved by adding the composition to an external object, and the effects of adding the composition to a source of aldehyde release, such as within a resin, remain unclear.

[0035] Patent Document 10 discloses a resin composition containing an epoxy resin, cellulose nanofibers, and a dihydrazide compound. However, in this resin composition, the dihydrazide compound is used as a curing agent for the epoxy resin and is not a VOC reducing agent, and its effectiveness as a VOC reducing agent is unclear.

[0036] Patent Documents 11 and 12 disclose low-VOC resin compositions with improved mold fouling resistance, comprising a combination of a polyacetal resin and a specific hydrazine compound. However, polyacetal resin is a formaldehyde-based resin composed of formaldehyde polymers as monomers, and has the property of releasing formaldehyde from the resin matrix itself. In this case, by mixing a hydrazine compound into the polyacetal resin and dispersing it as islands, a uniform formaldehyde-hydrazine chemical reaction can be expected, thereby achieving high aldehyde reduction efficiency.

[0037] On the other hand, in non-formaldehyde resins such as polyolefins containing lignocellulosic fibers, aldehydes are rarely released from the non-formaldehyde resin itself, so the lignocellulosic fibers are the sole source of formaldehyde generation. Unlike the technologies described in Patent Documents 11 and 12, hydrazine and lignocellulosic fibers exist as independent islands or distinct particles within the sea of ​​resin, with little opportunity for uniform association. Therefore, it is expected that the association and / or reaction between formaldehyde released from the lignocellulosic fibers and the hydrazine compound will be extremely uneven and inefficient. Therefore, when the technologies described in Patent Documents 11 and 12 are applied to the aforementioned non-formaldehyde resins, VOC reduction effects are unlikely. Naturally, foreseeing such effects is also difficult. Furthermore, the ability to reduce acetaldehyde, and furthermore, the ability to reduce aldehydes at elevated temperatures (e.g., 65°C), where release significantly increases, rather than at room temperature, and further, the ability to reduce aldehydes from lignocellulosic fibers, is uncertain.

[0038] The cause of the burning odor is explained by taking the process of kneading and molding a composition of a resin and lignocellulose, namely a composition of a polypropylene resin and lignocellulose fibers, as an example. The kneading and molding temperature of this resin composition often reaches approximately 200°C, which is above the melting point of the resin. When the kneading and molding temperature reaches approximately 200°C, a burning odor is generated due to the following reasons (1) and (2).

[0039] (1) Lignin decomposes due to high heat, producing a burnt odor.

[0040] (2) As a result of the thermal decomposition of hemicellulose, acidic compounds of the carboxylic acid series, such as acetic acid, are generated. These acidic compounds further promote the thermal decomposition of lignin, further generating a burnt odor.

[0041] Non-Patent Document 1 describes a 1:1 mixture of kraft pulp containing no lignin and / or hemicellulose and hemp pulp containing lignin and / or hemicellulose, mixed with polypropylene resin and heated. SPME-GC-MS analysis of the released gas components revealed the presence of large amounts of carboxylic acids and / or phenols, which originate from the hemp pulp containing lignin and / or hemicellulose. This indicates that the presence of lignin and / or hemicellulose significantly increases the generation of a burnt odor compared to the absence of lignin and / or hemicellulose.

[0042] Therefore, the present inventors have focused on the importance of a measure to suppress the decomposition and / or modification of these two thermally unstable components in order to reduce the burning odor, and have conducted intensive studies.

[0043] The present inventors have conducted intensive studies and have found that the burning odor generated due to the above-mentioned (1) can be suppressed by adding a specific porous adsorbent when kneading lignocellulose fibers and resin.

[0044] In addition, the present inventors have also found that by adding an alkaline compound when mixing lignocellulose fibers with resin, the acidic compounds produced by the above-mentioned (2) can be neutralized, thereby preventing the promotion of lignin decomposition caused by the acidic compounds and suppressing the generation of excessive burnt odor caused by the modification and / or thermal decomposition of lignin.

[0045] Furthermore, when the kneading and molding temperature of a polypropylene resin and lignocellulosic fiber composition reaches approximately 200°C, the hemicellulose in the lignocellulosic fibers oxidizes, modifies, and decomposes due to the heat, resulting in the generation of aldehydes and the release of formaldehyde and / or acetaldehyde. Furthermore, materials containing lignocellulosic fibers have the property of rapidly increasing VOC emissions above 40-50°C. When VOC emissions are tested at 65°C, as is required for automotive interior materials, greater VOC emissions are observed compared to tests conducted at room temperature, making it difficult to suppress VOC emissions at 65°C.

[0046] It should be noted that VOC is a general term for volatile organic compounds. Non-Patent Document 2 states that VOCs “do not include formaldehyde and other carbonyl compounds.” However, this specification does not specifically distinguish between these two categories and refers to all organic compounds released at the desired sampling temperature as VOCs.

[0047] To reduce the emission of relatively low-electrophilic aldehydes, the present inventors investigated the effects of relatively high-nucleophilic amines. As a result, they discovered that the addition of urea, a commonly used formaldehyde-reducing agent in wood materials for construction, could suppress aldehyde emissions to some extent. However, they discovered that the aldehyde-reducing reaction of urea is an equilibrium reaction, resulting in a limited reduction effect per unit amount added. Furthermore, when kneading and / or forming is performed above the melting point of urea, the urea melts and reacts to release ammonia, resulting in a strong ammonia odor and weakening the strength of the strands produced during kneading and ejection.

[0048] In order to solve these various problems, studies were conducted based on the following conditions: among amines, toxicity and / or corrosivity are low, there is no unpleasant odor, the melting point is higher than the kneading and / or molding temperature, or even if the kneading and / or molding temperature is close to the melting point, the odor and / or ammonia release is negligible. As a result, it was found that hydrazide compounds are effective in reducing aldehydes from lignocellulosic fibers.

[0049] The present invention has been completed based on these findings.

[0050] The present invention provides a low-odor composition for use as a fiber-reinforced resin material, which is prepared by kneading lignocellulosic fibers containing lignin, a resin, and an odor-reducing material. The odor-reducing material is one or both of activated carbon and a basic compound.

[0051] The present invention also provides a low-VOC resin composition for use as a fiber-reinforced resin material, which is obtained by kneading lignocellulosic fibers containing lignin, a resin, and a VOC-reducing material, wherein the VOC-reducing material contains a hydrazide compound. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is a schematic diagram showing a twin-screw extruder as an example of a multi-screw extruder used for producing the low-odor composition of the present invention.

[0053] Figure 2 This is a perspective top view of two screws arranged parallel to each other, omitting the barrel and viewed from above. DETAILED DESCRIPTION

[0054] Hereinafter, the present invention will be described in detail based on preferred embodiments thereof.

[0055] First, the low-odor composition of the present invention will be described. The low-odor composition of the present invention is prepared by kneading lignocellulosic fibers containing lignin, a resin, and an odor-reducing material, and is used as a fiber-reinforced resin material. The low-odor composition of the present invention can be produced, for example, by introducing the lignocellulosic fibers, the resin, and the odor-reducing material into a multi-screw extruder equipped with twin or more screws and kneading the three.

[0056] Due to the heat generated when the lignocellulose fibers and the resin are mixed, the lignin contained in the lignocellulose fibers is modified, and a burnt odor is generated. However, the low-odor composition of the present invention can suppress the burnt odor because it contains an odor-reducing material. Specifically, the odor-reducing material is either or both of activated carbon and an alkaline compound. By using activated carbon as the odor-reducing material, the burnt odor generated due to the reason (1) above can be suppressed. In addition, by using an alkaline compound as the odor-reducing material, the burnt odor generated due to the reason (2) above can be suppressed. In addition, by using both activated carbon and an alkaline compound as the odor-reducing material, it is possible to deal with the burnt odor that cannot be completely suppressed by only one of them in a multi-layered manner, and the use of relatively expensive activated carbon can be reduced.

[0057] Hereinafter, the lignocellulose fibers, resin, and odor-reducing material used in the low-odor composition of the present invention will be described.

[0058] [Lignocellulosic fiber]

[0059] The lignocellulosic fibers used in the present invention are obtained by subjecting a lignocellulosic material from a wood or non-wood plant to mechanical, thermomechanical, chemical, chemomechanical or chemothermomechanical treatment to soften or destroy, unravel or miniaturize the intermediate layer of fibers that are bound with an adhesive. As lignocellulosic fibers, such lignocellulosic fibers can be used without particular limitation. The wood can be either coniferous or broad-leaved. As lignocellulosic fibers from non-wood plants, straw pulp, bagasse pulp, reed pulp, kenaf pulp, linen pulp, ramie pulp, hemp pulp, flax pulp, bamboo pulp, etc. can be cited. Furthermore, the meaning of fiber and / or pulp also includes powders such as wood flour and / or finely pulverized material and / or sawdust.

[0060] As the lignocellulosic fibers used in the present invention, for example, lignocellulosic powder, semi-chemical pulp, chemical groundwood, refined groundwood, thermomechanical pulp, and woodchip pulp can be preferably used. From the perspective of cost, it is preferred that the fibers contain 5% or more of lignin. Among them, from the perspective of manufacturing efficiency and / or physical properties and cost, mechanical pulp or fiberboard fibers are preferably used. Examples of mechanical pulp include refined groundwood, thermomechanical pulp, and woodchip pulp. From the same perspective, thermomechanical pulp is more preferred. Thermomechanical pulp also includes fiberboard fibers. Fiberboard fibers are thermomechanical pulp in a broad sense and relatively coarse fibers within the thermomechanical pulp in a narrow sense.

[0061] As an example of the physical form of the fiber, thermomechanical pulp can be cited as having a diameter of about 30 μm and a length of about 2 to 3 mm. Furthermore, lignocellulosic fibers such as nanocellulose fibers (also called nanolignocellulose fibers) thinned to nanometer sizes in the length and width directions and / or microcellulose fibers (also called microlignocellulose fibers) obtained by mixing nanometer-sized or micrometer-sized fibers in the length and width directions can be exemplified. Even fine wood powder, also known as wood flour, which has an aspect ratio due to its different length and width dimensions, can be exemplified as a type of lignocellulosic fiber.

[0062] Lignocellulosic fibers are different from pulp that has been bleached (delignified) to a certain degree or more, and contain lignin and / or hemicellulose. Lignocellulosic fibers may be used alone or in combination of two or more.

[0063] As a method for converting a lignocellulose material into lignocellulose fiber, a known method can be used without particular limitation. For example, conventional methods for producing pulp and / or conventional methods for producing fiber for fiberboard, and a mill for pulverizing chips can be appropriately used.

[0064] As an example of a method for fiberizing a lignocellulosic material, the following method can be cited: the lignocellulosic material is crushed into fragments, and then, it is steamed while applying a pressure of about 1 to 10 Bar using a preheater and / or a pre-steamer to soften the lignin and / or hemicellulose that are components of the lignocellulosic material. Then, it is defibrated into fibers or fiber bundles using a disc cutter while applying pressure in a pressurized refiner to produce the desired fibers.

[0065] The lignocellulosic fibers used in the present invention preferably have a width of 1 μm to 100 μm, more preferably 10 μm to 50 μm, and a length of 0.1 mm to 50 mm, more preferably 1 mm to 5 mm. The length and / or width of these fibers can be adjusted to the desired length and / or width by adjusting operating conditions such as the spacing between the discs of the refiner.

[0066] Regarding lignocellulosic fibers, if you want to produce them while maintaining a high aspect ratio, hydrothermal production, as described above, is effective, as it also minimizes fiber damage. On the other hand, if you want a powder with a reduced aspect ratio, such as wood flour, a pulverizer and / or grinder can be used. The GHG rating of the material varies depending on the type of electricity and / or thermal energy used, so the material can be selected based on the intended purpose.

[0067] As a method for producing nanocellulose fibers or microcellulose fibers, any known method can be used, such as a method of mechanically refining to a desired size, a method of refining by applying an external force in water or a resin after chemical modification, or a method combining these methods.

[0068] The weight ratio of the lignin component in the lignocellulosic fibers used in the present invention is preferably 5% to 50%, more preferably 5% to 45%, and even more preferably 5% to 40%. By setting the weight ratio of the lignin component in the lignocellulosic fibers within the above range, the amount of odor-reducing material added can be reduced to a suitable amount, thereby preventing the odor-reducing material from undesirably affecting the physical properties of the kneaded product and reducing the cost of the odor-reducing material.

[0069] Furthermore, in many cases, lignocellulosic fibers are dried for the purposes of transportation and / or preservation, storage, and / or to improve handling. Known methods can be used for drying lignocellulosic fibers without particular limitation. Examples include methods in which wet lignocellulosic fibers are sprayed onto rollers and / or wires, dehydrated by suction and / or pressure, and then heat-dried, as is done in the paper and pulp industry; and / or methods in which wet lignocellulosic fibers are heat-dried in a hot air duct under an airflow, as is done in the manufacture of fibers for fiberboards. Such drying of lignocellulosic fibers is preferably performed at a temperature of, for example, 60°C to 200°C, more preferably 80°C to 160°C, and even more preferably 100°C to 140°C.

[0070] In recent years, methods for defibration and fiber production under dry conditions without using hydrothermal conditions have also become popular. In some cases, fibers produced under conditions other than hydrothermal conditions are acceptable for cost and / or quality reasons. In such cases, fibers produced under dry conditions may also be acceptable.

[0071] [Resin]

[0072] The resin used in the present invention is preferably a thermoplastic resin. The melting point of the thermoplastic resin is preferably 260°C or lower. In addition, the thermoplastic resin preferably has a certain degree of heat resistance. Specifically, the melting point is preferably 100°C or higher.

[0073] Examples of the thermoplastic resin include one or more selected from the group consisting of polyethylene, polypropylene, polyvinyl alcohol, polyvinyl acetate, polyvinyl chloride, polystyrene, polylactic acid, polyacetal, polyamides, polyhydroxyalkanes, acrylonitrile-butadiene-styrene copolymers, polyurethanes, modified resins thereof, copolymer resins, and polymer alloys.

[0074] The thermoplastic resin may be in the form of a compression molded body, and / or powder, granules, or fibers, and is preferably in the form of pellets.

[0075] [Odor reduction material]

[0076] As described above, the odor-reducing material used in the present invention is used to reduce the burnt odor originating from lignocellulosic fibers. Examples of odor-reducing materials include activated carbon and alkaline compounds. In the low-odor composition of the present invention, the odor-reducing material is either or both of the activated carbon and the alkaline compound.

[0077] [Activated carbon]

[0078] Activated carbon is particularly effective in adsorbing burnt odors originating from lignocellulosic fibers caused by heat.

[0079] Activated carbon is primarily made by thermally decomposing (carbonizing) the volatile substances in raw materials such as wood sawdust and / or coconut shells, or coal powder under an inert atmosphere, and then subjecting them to a treatment called activation with chemicals and / or steam to develop pores. Furthermore, depending on the intended use, neutralization and / or cleaning may be performed, ash may be extracted with acid to increase purity, or chemical agents may be applied to enhance adsorption. Replacing non-renewable materials previously used in fiber-reinforced resin materials with lignocellulosic fibers offers advantages such as material weight reduction, improved LCA, and / or cost reduction. Therefore, activated carbon derived from wood sawdust and / or coconut shells is preferred over activated carbon derived from coal, a fossil resource.

[0080] As the apparent shape of the activated carbon, a molded body such as a binder, a powder, a granular, a crushed or spherical shape can be listed. In order to effectively disperse in the resin, the apparent shape of the activated carbon is preferably powdered when compounding or kneading. The size of the powder can be listed as more than 0.01 μm and less than 1000 μm, preferably more than 0.1 μm and less than 500 μm, more preferably more than 1.0 μm and less than 50 μm. The finer the size, the more the specific surface area increases, the more the adsorption capacity improves, and the less the influence on the physical properties and / or surface properties of the resin composition, but on the other hand, it is easy to produce dust and become significant, processing costs energy, time and / or cost, and the volume becomes larger.

[0081] The method for measuring the size of the activated carbon powder can be any known method without particular limitation. For example, a particle size measurement method based on "JIS K 1474 (2014) Activated Carbon Test Methods" or a measurement method using a commercially available powder particle size distribution measuring device can be used.

[0082] The specific surface area of ​​activated carbon can be used as a standard for adsorption capacity. The unit of specific surface area is “m 2 / g". As the specific surface area of ​​activated carbon, 50m 2 / g and above 10000m 2 / g or less, preferably 100m 2 / g and above and 5000m 2 / g or less, more preferably 200m 2 / g and above and 3000m 2 From the viewpoint of improving the adsorption capacity of activated carbon, it is preferred that the activated carbon have a large specific surface area, but this is also determined in consideration of cost.

[0083] As a method for measuring the specific surface area of ​​activated carbon, a known method can be adopted without particular limitation. For example, a mercury porosimetry method, a gas adsorption method, an air permeation method, etc. can be used.

[0084] Activated carbon normally absorbs most of the moisture in the surrounding atmosphere, but adding more moisture can also be beneficial. This is because, as one of the VOC reduction measures for thermoplastic resins, the goal is to achieve the effect of introducing moisture into the mix during resin kneading, vaporizing it as water vapor using the heat of kneading, thereby promoting the release of low-molecular VOCs and / or odors out of the system. Furthermore, this is to suppress the undesirable dispersion of dust generated during operation.

[0085] As mentioned above, for the purpose of effectively dispersing in the resin, the shape of the activated carbon is preferably powdered, but powdered activated carbon is very light and bulky, so when the materials are mixed and / or supplied to the kneading device, dust may be raised and significantly pollute the surroundings. Therefore, by making the activated carbon a hydrous activated carbon containing a certain amount of water, dust pollution to the surroundings can be prevented. In addition, generally speaking, if there is excessive water during kneading, there may be poor kneading and / or strand breakage, condensation in the device, backflow of the kneaded material, mixing of bubbles into the kneaded material, etc., so it is considered taboo to contain water when kneading with the resin. However, in the case of manufacturing the low-odor composition of the present invention, by dispersing and slowly releasing water with the help of activated carbon and / or lignocellulose fibers, even if water is contained, it is relatively less likely to cause problems in the kneading process. In addition, by setting the mixture to contain an appropriate amount of water, it is also possible to easily promote the release of odor components together with water vapor to the outside of the system during kneading.

[0086] The hydrated activated carbon preferably contains water in a mass ratio of 20% or more and 70% or less relative to the dried activated carbon, and more preferably contains water in a mass ratio of 30% or more and 60% or less. If the activated carbon powder is allowed to absorb moisture under the conditions of 20°C and 95% humidity, it usually takes more than 2 to 3 weeks until the moisture content exceeds 20%. Therefore, when the moisture content of the activated carbon exceeds 20%, it can be determined that it has intentionally absorbed moisture. Here, the moisture content (%) of the activated carbon can be calculated by the following formula (1).

[0087] Moisture content of activated carbon (%) = {(weight of water) / (weight of dry activated carbon + weight of water)} × 100 (1)

[0088] If the activated carbon contains too much water, it will form gas bubbles during kneading and / or mixing, or cause excessive pressure buildup, which can easily lead to problems such as condensation within the equipment, unstable material supply to the equipment, material agglomeration, and material backflow within the equipment. Conversely, if the water content is too low, it will be difficult to solve the problem of dust flying. To address these issues, the water content of the hydrous activated carbon is preferably within the above range.

[0089] Furthermore, activated carbon coated with a chemical has been put into practical use for the purpose of facilitating the adsorption of exhaust gases and odors. For example, an alkaline chemical is applied to acidic exhaust gases, while an acidic chemical is applied to alkaline exhaust gases, thereby enhancing the adsorption effect. The activated carbon used in the present invention can be selected from such chemical-coated activated carbons. The acidity or alkalinity of such activated carbon is preferably neutral to alkaline.

[0090] It should be noted that, within the scope not impairing the purpose of the present invention, a highly heat-resistant liquid such as silicone oil may be used to impart binding properties to the activated carbon powder to suppress scattering.

[0091] [Basic compounds]

[0092] In the present invention, the basic compound can be used to neutralize the acidic compounds generated by thermal decomposition of hemicellulose to prevent the accelerated decomposition of lignin and / or to suppress the odor derived from carboxylic acid.

[0093] As the basic compound, any compound showing alkalinity can be used without particular limitation, but it is not preferred that the compound be toxic to living things, corrosive to devices, have adverse effects on the environment, or produce unpleasant odors.

[0094] As the example of alkaline compounds, any one of organic compounds and inorganic compounds can be enumerated. If expectation does not decompose and stably plays a role when hot working, metal oxides, metal hydroxides, metal carbonate compounds, metal silicon compounds and / or their heterocyclic compounds as inorganic compounds can be enumerated. Considering the actual performance of compounding in resin combination, easy to obtain, cost etc., oxides and / or hydroxides of alkali metals and / or oxides and / or hydroxides of alkaline earth metals can be enumerated, preferably magnesium oxide and / or magnesium oxide, calcium oxide and / or calcium hydroxide etc. In the case of containing hemicellulose in lignocellulose fiber, in order to avoid the decomposition of hemicellulose, preferably weakly basic compounds are used. As the example of such compound, magnesium hydroxide can be enumerated. In order to improve the dispersibility in resin, the surface of such alkaline compounds can be processed with coupling agent and / or compatibilizing agent, fatty acid etc., and can also be expected to maximize the neutralization effect and be untreated.

[0095] These compounds are preferably in powder form, considering ease of mixing with the resin, but may also be in slurry form and / or aqueous solution form within the scope of not impairing the purpose of the present invention. In addition, as described above, a method of pre-adhering a compound that increases acidity and / or other adsorption to the activated carbon may also be used.

[0096] [Low odor composition]

[0097] The composition of the low-odor composition of the present invention can be appropriately determined according to the type of compounding and / or resin and the application of the low-odor composition.

[0098] As an example of the composition of the low-odor composition of the present invention, the blending ratio of the lignocellulosic fiber can be a fiber blending ratio (weight) for directly supplying to a forming device (e.g., 10 to 70%), or a high fiber blending ratio (weight) for newly diluting with a resin (e.g., 30 to 99%).

[0099] From the viewpoint of improving physical properties and reducing emissions of fossil resources and / or greenhouse gases therefrom, the low-odor composition of the present invention preferably contains, by mass, 1% or more and 95% or less of lignocellulose fibers, more preferably 3% or more and 85% or less, and even more preferably 5% or more and 75% or less.

[0100] As an example of the composition of the low odor composition of the present invention, the blending ratio of the odor reducing material varies depending on the addition rate of the lignocellulosic fiber and / or the thermal history to which the lignocellulosic fiber is subjected, and the lignin ratio in the lignocellulosic fiber, and can be, for example, 0.1 to 20% relative to the whole, and 0.1 to 300% relative to the lignocellulosic fiber.

[0101] The specific gravity of the low-odor composition of the present invention varies depending on the blending ratio and / or the presence or absence of other additives (e.g., glass fiber, talc, calcium carbonate, basalt fiber, etc. with high specific gravity), and is 0.7 to 1.7, preferably 0.8 to 1.6, and more preferably 0.9 to 1.5.

[0102] The bulk density of the low-odor composition of the present invention also varies depending on the blending ratio and / or other additives, and can be 100 to 800 kg / m 3 , preferably 150~600kg / m 3 , more preferably 200 to 500 kg / m 3 .

[0103] The moisture content of the low-odor composition of the present invention during treatment (Japanese: extraction) is 0 to 20%, preferably 0 to 15%, and more preferably 0 to 10%. In this case, the moisture content (%) can be calculated by the following formula (2).

[0104] Moisture content (%) = {(mass of water) / (mass of the whole)} × 100 (2)

[0105] The moisture content can be measured by a method in which the weight loss due to drying or the like is used as the moisture content, or by a method using a commercially available moisture meter (for example, a Karl Fischer moisture meter).

[0106] Furthermore, the low-odor composition of the present invention preferably includes hydrous activated carbon as an odor-reducing material. The hydrous activated carbon contains 20% to 70% water by mass, and the water is released as steam during the kneading of the lignocellulosic fibers, resin, and the odor-reducing material. The low-odor composition, in which water is released as steam during kneading, facilitates the release of odorous components such as burnt odors along with the steam, thereby further reducing burnt odors. It should be noted that, in a low-odor composition in which water is released as steam during the kneading of the lignocellulosic fibers, resin, and the odor-reducing material, it is virtually impossible to analyze the entire particle structure and / or properties that contribute to the effects of the present invention. Specific identification based on the structure and properties would require significantly excessive financial expenditure and time. Therefore, with respect to the aforementioned low-odor composition, there are cases where it is impossible or largely impractical to directly identify the substance based on its structure or properties at the time of filing this application, i.e., "impossible / impractical."

[0107] [Method for producing low-odor composition]

[0108] The low-odor composition of the present invention is obtained by mixing lignocellulosic fibers, resin, and odor-reducing materials. The lignocellulosic fibers, resin, and odor-reducing materials can be mixed, for example, using a mixing device such as a multi-screw extruder, a high-pressure kneader, a Banbury mixer, a Henschel mixer, or a roller mill. The lignocellulosic fibers, resin, and odor-reducing materials can be pre-mixed before being put into the mixing device, or the lignocellulosic fibers, resin, and odor-reducing materials can be put into the mixing device from the same inlet or different inlets for the purpose of mixing them in the mixing device. For example, the resin can be put into the mixing device first, and after the resin is melted, the lignocellulosic fibers and / or odor-reducing materials can be put into the mixing device in sequence. Alternatively, the resin, lignocellulosic fibers, and odor-reducing materials can be put into the mixing device at the same time, and the resin, lignocellulosic fibers, and odor-reducing materials can be mixed while the resin is melted.

[0109] [Multi-screw extruder]

[0110] To obtain the low-odor composition of the present invention, it is preferred to use a multi-screw extruder having two or more screws. Multi-screw extruders that can be used to produce the low-odor composition of the present invention include twin-screw extruders having two screws and multi-screw extruders having three or more screws.

[0111] Figure 1The present invention shows a twin-screw extruder 1 as an example of a multi-screw extruder that can be used to produce the low-odor composition of the present invention. The twin-screw extruder 1 includes a screw 3 for kneading, a barrel 2, a heating device 8, a nozzle 7 having an extrusion port 71, a material input portion 6, and a degassing portion (not shown) for vacuum degassing gas components generated during kneading. The barrel 2 has a kneading space inside which the screw 3 is arranged. The twin-screw extruder 1 is as shown in FIG. Figure 1 and Figure 2 As shown, in the kneading space of the barrel 2, two screws 3 are arranged in parallel so that the screw shafts 31 serving as the rotation axes thereof are parallel to each other and can rotate freely. Figure 2 As shown, the screw blades 32 are provided to mesh with each other. The heating device 8 includes a plurality of heating sections 81 arranged along the axial direction of the barrel 2 on the outer periphery of the barrel 2. A plurality of heating sections 81 are provided along the axial direction of the barrel 2 from the material input section 6 to the nozzle section 7. As the heating section 81, for example, a heater with a heating wire and / or a heater through which a high-temperature heat medium is passed can be used.

[0112] The twin-screw extruder 1 includes, for example, an electric motor as a drive source 4 for the two screws 3 . Power is transmitted from the drive source 4 to the screw shafts 31 of the two screws 3 via a transmission system 5 such as a gear mechanism, thereby rotating the two screw shafts 31 .

[0113] The twin-screw extruder 1 includes a heating region Rh that can be heated by the heating device 8 . The heating region Rh extends in the axial direction of the barrel 2 . Figure 1 In the twin-screw extruder 1 shown, a heating portion 81 of a heater 8 is disposed in the heating region Rh. The heating region Rh can be divided into a plurality of zones S1 to S11 along the axial direction of the barrel 2. Here, a zone refers to a region whose temperature can be independently set. Figure 1 The twin-screw extruder 1 shown is divided into 11 zones S1 to S11. When the heating region Rh is observed along the axial direction of the barrel 2, a heating section 81 is provided in each zone. The number of heating sections 81 provided in one zone is not limited to one, and a plurality of heating sections 81 may be provided in one zone. By providing a heating section 81 in each zone, the twin-screw extruder 1 can set the temperature according to each stage of the mixing and transfer of the material. It should be noted that the number of zones is not limited to 11, and may be 1, 2 or more and 10 or less, or 12 or more.

[0114] Hereinafter, a preferred embodiment of the method for producing a low-odor composition of the present invention will be described by taking as an example a method for producing a low-odor composition using the above-mentioned twin-screw extruder 1. The production method of this embodiment includes a kneading step.

[0115] In the kneading step, the lignocellulosic fibers A, the thermoplastic resin B, and the odor reducing material C are forcibly transferred to the downstream side where the nozzle portion 7 is located by the rotation of the screw 3 .

[0116] The kneading step of this embodiment includes a melting step and a low-temperature kneading step.

[0117] The melting process is carried out in at least one partition. In the present embodiment, the melting process is carried out in partition S1. In the melting process, the set temperature of the heating section 81 is maintained at or above the melting point of the thermoplastic resin B, and the thermoplastic resin B is melted to obtain a mixture of the lignocellulosic fibers A, the odor reducing material C, and the melted thermoplastic resin B. The partitions for the high-temperature kneading process may be one or two or more. In the melting process, the thermoplastic resin B alone may be melted, and then the melted thermoplastic resin B, the lignocellulosic fibers A, and the odor reducing material C are mixed. Alternatively, the thermoplastic resin B containing the lignocellulosic fibers may be melted, and then the melted thermoplastic resin B, the lignocellulosic fibers A, and the odor reducing material C are mixed. Alternatively, the thermoplastic resin B containing the lignocellulosic fibers and the odor reducing material may be melted, and then the melted thermoplastic resin B, the lignocellulosic fibers A, and the odor reducing material C are mixed.

[0118] The low-temperature kneading step is performed after the melting step. The melting step is performed in at least one partition. In the present embodiment, the low-temperature kneading step is performed in partitions S2 to S11. During the low-temperature kneading step, the mixture obtained in the melting step is kneaded while the set temperature of the heating section 81 is maintained below the melting point of the thermoplastic resin B. Furthermore, in the present embodiment, after the low-temperature kneading step, the mixture is ejected from the extruder 71 to obtain a low-odor composition D. The low-temperature kneading step may be performed in one partition or in two or more partitions.

[0119] In this embodiment, a granulation step is preferably included after the kneading step. After the mixture is ejected from the extruder 71, the ejected low-odor composition D is cut lengthwise to form pellets. The inclusion of the granulation step allows for efficient use of the low-odor composition D. In the granulation step, known methods for cutting the low-odor composition D include hot cutting without cooling it in a water tank, air cooling and / or water cooling, and cutting the low-odor composition D in water after ejecting it. The ejected low-odor composition D can be cut into desired lengths.

[0120] The production method of this embodiment includes a low-temperature kneading step, which can reduce the thermal history of the lignocellulosic fibers. As a result, the thermal decomposition of lignin caused by the above-mentioned reason (1) can be suppressed. From the perspective of suppressing the burning odor caused by the above-mentioned reason (2), the odor-reducing material used in the production method of this embodiment preferably contains an alkaline compound.

[0121] In the production method of this embodiment, the ratio of the number of partitions performing the low-temperature kneading step to the number of partitions performing steps subsequent to the melting step (hereinafter also referred to as the partition ratio) is preferably 15% or more and 100% or less, more preferably 20% or more and 100% or less, and even more preferably 25% or more and 100% or less. By setting the partition ratio within the above range, the effect of efficiently and easily obtaining the low-odor composition of the present invention can be more significantly exerted. The partition ratio can be calculated using the following formula (3).

[0122] Partition ratio % = {(number of partitions where the low-temperature kneading step is performed) ÷ (number of partitions where the steps after the melting step are performed)} × 100 (3)

[0123] In the production method of this embodiment, the ratio of the time required for the partition to pass through the low-temperature kneading step to the time required for the partition to pass through the subsequent steps of the melting step is preferably 10% or more and 100% or less, more preferably 15% or more and 100% or less, and even more preferably 20% or more and 100% or less. By setting the ratio of the aforementioned time within the above range, the effect of efficiently and easily obtaining the low-odor composition of the present invention can be more significantly exerted. The ratio of the aforementioned time can be calculated using the following formula (4).

[0124] The ratio of the above time % = {(time required for the partition to pass the low-temperature kneading process) ÷ (time required for the partition to pass the process after the melting process)} × 100 (4)

[0125] Next, the low-VOC resin composition of the present invention will be described. The low-VOC resin of the present invention is a low-VOC resin composition used as a fiber-reinforced resin material, obtained by kneading lignocellulosic fibers containing hemicellulose, a resin, and a VOC-reducing material. The low-VOC resin composition of the present invention can be produced, for example, by introducing the lignocellulosic fibers, the resin, and the VOC-reducing material into a multi-screw extruder equipped with twin or more screws and kneading the three.

[0126] Due to the heat generated when mixing lignocellulosic fibers and resin, the hemicellulose contained in the lignocellulosic fibers is oxidized, modified, or decomposed, generating VOCs such as carboxylic acids and / or aldehydes. However, the low-VOC resin composition of the present invention contains a VOC-reducing material, thereby suppressing the generation of VOCs. Specifically, the VOC-reducing material contains a hydrazide compound. By including a hydrazide compound in the VOC-reducing material, a low-VOC resin composition with suppressed VOC generation can be produced at low cost.

[0127] Hereinafter, the lignocellulosic fibers, resin, and VOC-reducing material used in the low-VOC resin composition of the present invention will be described.

[0128] The low-VOC resin composition of the present invention can use the same lignocellulose fibers and resins as those used in the low-odor composition of the present invention.

[0129] The mass proportion of the hemicellulose component in the lignocellulosic fibers used in the present invention is preferably from 1% to 30%, more preferably from 2% to 25%, and even more preferably from 3% to 20%. By setting the mass proportion of the hemicellulose component in the lignocellulosic fibers within the above range, the amount of VOC-reducing material added can be reduced to an appropriate level, thereby preventing the VOC-reducing material from undesirably affecting the physical properties of the kneaded product and reducing the cost of the VOC-reducing material.

[0130] [VOC reduction materials]

[0131] The VOC reducing material used in the low-VOC resin composition of the present invention effectively functions to reduce VOCs, particularly aldehydes, derived from lignocellulose fibers due to heat.

[0132] The VCO-reducing material used in the present invention is preferably a hydrazide compound. Examples of the hydrazide compound include monohydrazide, dihydrazide, and polyhydrazide compounds, with dihydrazide compounds being preferred. Examples of such dihydrazide compounds include dibasic acid dihydrazides such as oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, dodecanedioic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, diglycolic acid dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, dimer acid dihydrazide, and 2,6-naphthoic acid dihydrazide. These hydrazide compounds may be used alone or in combination of two or more.

[0133] The hydrazide compound can be used in the form of a powder mixed with lignocellulosic fibers and / or resin, or can be preliminarily attached to lignocellulosic fibers and / or resin with water as an aqueous solution or a binder such as silicone oil, or mixed with other coexisting additives such as activated carbon.

[0134] Furthermore, it is known that the amount of aldehydes released can be further effectively reduced by combining a hydrazide compound with a carboxylic acid and / or a carboxylate salt. Such known capture-promoting materials can be used without particular limitation as long as they are suitable for the purpose of the present invention.

[0135] Here, for example, if we consider the mixing state of polyolefin resin, lignocellulose fibers, and hydrazide compounds, we can imagine that in a sea of ​​polyolefin resin, lignocellulose fibers and hydrazide compounds exist as islands in an isolated state. In this state, considering the occasional and extremely low probability of association between the two, it is expected that the hydrazide compound is ineffective in capturing aldehydes released from lignocellulose. However, as described in the examples described later, in the present invention, since the release of aldehydes can be effectively reduced with a very small addition rate of hydrazide compounds, it is believed that there is a new mechanism that was previously unimaginable. That is, it is proposed that in a sea of ​​resin, the polar lignocellulose and hydrazide compounds both exert their polar affinity, resulting in a mutual attraction. Compared to the state of isolated individuals, the two are in a close state, and the hydrazide compound can efficiently capture aldehydes released from the lignocellulose. This new mechanism and new effects based on this are also proposed. It should be noted that the same mechanism is also proposed with respect to the addition of urea compounds.

[0136] The low VOC resin composition of the present invention may also contain a urea compound as a VOC-reducing aid in addition to the hydrazide compound. The urea compound broadly includes urea and its similar compounds and / or derivatives, but considering the cost and / or ease of acquisition, urea is preferred. Generally, condensation compounds of acids with ammonia and / or amines, and their similar compounds and / or derivatives mostly generate ammonia when hydrolyzed and / or melted. Urea also melts when exposed to heat above its melting point, releasing ammonia. Therefore, when a large amount is mixed, ammonia is sometimes generated due to the heat during mixing and / or molding, producing a unique ammonia odor. Therefore, although it is necessary to pay attention to the mixing amount, through careful combination, the mixing amount of the relatively expensive hydrazide compound can be reduced, and the urea compound can play the role of reducing VOC.

[0137] The urea compound may be mixed with the lignocellulose fibers and / or resin in the form of powder and / or granules, or may be preliminarily attached to the lignocellulose fibers and / or resin via a binder such as water or silicone oil as an aqueous solution before compounding.

[0138] [Low VOC resin composition]

[0139] The composition of the low-VOC resin composition of the present invention can be appropriately determined according to the type of compounding and / or resin and the application of the low-VOC resin composition.

[0140] As an example of the composition of the low-VOC resin composition of the present invention, the blending ratio of the lignocellulosic fiber can be a fiber blending ratio (weight) for directly supplying to a molding device (e.g., 10 to 70%), or a high fiber blending ratio (weight) for newly diluting with a resin (e.g., 30 to 99%).

[0141] The blending ratio (mass) of the hydrazide compound varies depending on the blending ratio and / or type of the co-blended lignocellulosic fibers and the thermal history, and therefore cannot be generalized. As an example, it is 0.01 to 20% relative to the total weight, preferably 0.05 to 10%, and more preferably 0.1 to 5%. If the blending ratio is too low, the VOC reduction effect is not achieved. Conversely, if it is too high, the physical properties and / or processability and appearance of the resin composition are degraded, or the hydrazide compound itself generates a heating odor.

[0142] From the viewpoint of the physical properties and / or cost of the kneaded product, the low-VOC resin composition of the present invention preferably contains 0.1% by mass to 5% by mass of the hydrazide compound, more preferably 0.2% by mass to 5% by mass, and even more preferably 0.3% by mass to 5% by mass.

[0143] The blending ratio (weight) of the urea compound varies depending on the blending ratio and / or type of the simultaneously blended lignocellulosic fibers and / or hydrazide compounds, and the thermal history, so it cannot be generalized. As an example, it can be 0.01 to 20%, preferably 0.05 to 10%, and more preferably 0.1 to 5% relative to the total weight. If the blending ratio is too low, the effect of reducing the blending ratio of VOC and / or hydrazide cannot be achieved. On the contrary, if it is too high, the physical properties and / or processability and appearance of the resin composition are reduced, or an ammonia odor is generated during heating. The urea compound can also be attached to the lignocellulosic fibers, especially in the form of urea and / or urea-formaldehyde resin, and used as a lignocellulosic fiber source containing the urea compound. This can be exemplified by materials such as fiberboard manufactured using urea-formaldehyde adhesives.

[0144] The specific gravity of the low-VOC resin composition of the present invention varies depending on the blending ratio and / or the presence or absence of other additives (e.g., glass fiber, talc, calcium carbonate, basalt fiber, etc. with high specific gravity), and is 0.7 to 1.7, preferably 0.8 to 1.6, and more preferably 0.9 to 1.5.

[0145] The bulk density also varies depending on the mixing ratio and / or other additives, and can be 100 to 800 kg / m 3, preferably 150~600kg / m 3 , more preferably 200 to 500 kg / m 3 .

[0146] The moisture content of the low-VOC resin composition of the present invention during treatment is 0 to 20%, preferably 0 to 15%, and more preferably 0 to 10%. In this case, the moisture content (%) can be calculated by the above formula (2).

[0147] The low-VOC resin composition of the present invention preferably satisfies the following (1) or (2) in the JASO M902 test.

[0148] (1) The formaldehyde release concentration of the sampling bag at a heating temperature of 65°C is 100 μg / m 3 the following.

[0149] (2) The acetaldehyde release concentration of the sampling bag at a heating temperature of 65°C is 48 μg / m 3 the following.

[0150] JASO M902 specifies methods for measuring VOC emissions from materials used in interior materials such as automotive instrument panels and / or door panels. The low-VOC resin composition of the present invention, by meeting the guideline values ​​of (1) or (2) above, serves as a basis for simulating VOC emissions under conditions of use in automotive interiors.

[0151] [Method for producing low-VOC resin composition]

[0152] The low-VOC resin composition of the present invention can be produced in the same manner as the low-odor composition of the present invention. Specifically, in the method for producing the low-odor composition of the present invention, the low-VOC resin composition of the present invention can be produced by using a VOC reducing material instead of an odor reducing material.

[0153] To obtain the low-VOC resin composition of the present invention, the multi-screw extruder described above can be used. In a preferred embodiment of the method for producing the low-VOC resin composition of the present invention, the twin-screw extruder 1 described above can also be used. The method for producing the low-VOC resin composition of this embodiment can be carried out in the same manner as the method for producing the low-odor composition of this embodiment described above, except that a VOC-reducing material is used instead of the odor-reducing material C.

[0154] The method for producing the low-VOC resin composition of the present embodiment includes a low-temperature kneading step, thereby reducing the thermal history of the lignocellulose fibers, thereby reducing the thermal decomposition of hemicellulose and suppressing the chance of further aldehyde generation.

[0155] Hereinafter, the common features of the low-odor composition and the low-VOC resin composition of the present invention will be described.

[0156] [Recycled materials]

[0157] The low-odor composition and low-VOC resin composition of the present invention can be recycled materials. Recycled materials refer to materials that are used to melt discarded thermoplastic resin materials with heat, repel them (or, in the case of leaving them in a crushed state without pelletization), thermoform them, and reuse them as resin products. Discarded materials in this context have a broad meaning and include materials generated during the manufacturing process before the product is delivered to the consumer, materials recovered after the consumer uses the product, runners and / or sprues generated during molding, rejects, and other waste materials within the manufacturing plant, regardless of whether they are actually used or intended for disposal.

[0158] The low-odor composition and low-VOC resin composition of the present invention may contain waste thermoplastic resin as the resin. In addition, the low-odor composition and low-VOC resin composition of the present invention may also be used as waste materials used to produce recycled materials.

[0159] The composition of lignocellulosic fiber and thermoplastic resin has the characteristics of a material suitable for regeneration, such as less fiber breakage and less degradation of physical properties, compared to brittle fibers such as glass fibers, due to the soft nature of lignocellulosic fiber, even after multiple regeneration processes (for example, crushed and re-pelletized after use, and then re-formed), etc. However, as mentioned above, when lignocellulosic fiber undergoes a thermal processing step, it also produces problems such as thermal oxidation, thermal attenuation and / or thermal degradation, and thermal decomposition of lignin, which easily generates a burnt odor. To address this problem, by compounding the composition of lignocellulosic fiber resin with an odor-reducing material compared to before regeneration, or by appropriately adding an odor-reducing material during regeneration, it is possible to achieve the effect of not easily generating a burnt odor even after multiple regeneration thermal processes.

[0160] [Lignocellulose fiber reinforced resin material]

[0161] The low-odor composition and low-VOC resin composition of the present invention both contain recyclable, lightweight, highly elastic lignocellulosic fibers with excellent LCA evaluations. Therefore, when used as fiber-reinforced resin materials, they can exhibit excellent lightweighting effects, reinforcement effects, and LCA improvement effects, resulting in high-performance fiber-reinforced resin materials.

[0162] To the extent that the effects of the present invention are not impaired, various additives such as preservatives, insecticides, mildewproofing agents, water repellents, ultraviolet absorbers, flame retardants, fillers, coupling agents, rubbers, elastomers, defoamers, foaming agents, lubricants, pigments, pigments, defoamers, foaming agents, waxes, mold release agents, fluidity improvers, strand reinforcing agents, antioxidants, other adsorbents, and other deodorants may be added to the fiber-reinforced resin material containing the low-odor composition or low-VOC resin composition of the present invention (hereinafter also referred to as "lignocellulose fiber resin reinforced material") . They may be used alone or in combination of two or more. In addition, these additives may be appropriately compounded at any stage, including the stage before the lignocellulose fiber reinforced resin material is made. In particular, liquid odor reducing materials and / or VOC reducing materials are usually attached to the surface of the resin molded product (semi-finished product or finished product) by spraying and / or coating.

[0163] The meaning of reinforced resin material includes not only the final product, but also the raw materials for manufacturing the product, such as the composition of lignocellulose fiber and resin, intermediates in the process of manufacturing the composition of lignocellulose fiber and resin and / or their mixtures.

[0164] The low-odor composition and low-VOC resin composition of the present invention can be sold as individual compositions, as intermediates such as masterbatches for dilution, as final molded products, and as aggregates and / or assemblies including molded products. While preferred embodiments of the present invention have been described above, the inventions are not limited to the aforementioned embodiments and can be modified as appropriate.

[0165] Example

[0166] The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples.

[0167] [Manufacturing of a Composition of Lignocellulosic Fiber, Thermoplastic Resin, and Odor Reducing Material]

[0168] Wood fibers containing lignin and / or hemicellulose (called thermomechanical pulp or MDF fiber) with radiata pine as the main raw material, thermoplastic resin, alkaline compound, activated carbon are appropriately mixed, and pellets made from the compositions of Examples 1 to 6, Comparative Examples 1 to 4, and Reference Example 1 are manufactured by the manufacturing method of the present embodiment described above. In the pelletizing process, as a method of cutting the low-odor composition, a method of cutting the low-odor composition after water cooling is used. The composition of the materials used in the manufacture of each pellet is described below. The set temperatures of each partition when manufacturing the compositions of Examples 1 to 6 and Comparative Examples 1 to 4 are shown in Table 1. The set temperatures of each partition when manufacturing the composition of Reference Example 1 are shown in Table 2. It should be noted that in Tables 1 and 2, partition S11 is the nozzle part. In addition, the set temperatures of the partitions that have not been set to a temperature before partition S1 are omitted from Tables 1 and 2. The screw speed when manufacturing the compositions of Examples 1 to 6, Comparative Examples 1 to 4, and Reference Example 1 was set to 250 rpm.

[0169] [Table 1]

[0170] Partition S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 S11 (nozzle) Temperature (℃) 180 100 100 100 100 100 100 100 100 170 180

[0171] [Table 2]

[0172] Partition S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 S11 (nozzle) Temperature (℃) 180 180 180 180 180 180 180 180 180 180 180

[0173] [Molded products]

[0174] The pellets of Examples 1 to 8, Comparative Examples 1 to 4, and Reference Example 1 were molded into a flat plate shape of 2 mm in thickness, 100 mm in length, and 100 mm in width using an injection molding machine to produce molded products.

[0175] (Composition of Example 1)

[0176] Resin: Polypropylene (Sumitomo Chemical: Z101A) 66 parts by mass

[0177] Compatibilizing material: Maleic acid-modified polypropylene (Riken Vitamin Co., Ltd.: MG441P) 1 part by mass

[0178] Lignocellulosic fiber: 30 parts by mass

[0179] Alkaline compound: 3 parts by mass of ultrafine calcium hydroxide (Omi Chemical Industry: Caldic 2000)

[0180] (Composition of Example 2)

[0181] The same procedures as in Example 1 were carried out except that the basic compound was changed as follows.

[0182] Alkaline compound: calcium hydroxide powder (Shiraishi Industries: CLS-B): 3 parts by mass

[0183] (Composition of Example 3)

[0184] The same procedures as in Example 1 were carried out except that the basic compound was changed as follows.

[0185] Alkaline compound: magnesium hydroxide powder (Kanto Chemical): 3 parts by mass

[0186] (Composition of Comparative Example 1)

[0187] The same procedures as in Example 1 were carried out except that no basic compound was contained.

[0188] (Composition of Reference Example 1)

[0189] The same procedures as in Example 1 were performed except that no alkaline compound was contained and 30 parts by mass of cellulose (FUJIFILM Wako Pure Chemical Corporation) was used instead of the lignocellulose fibers.

[0190] [evaluate]

[0191] The pellets of Examples 1 to 3, Comparative Example 1, and Reference Example 1 were evaluated for burnt odor by the following method. In other words, the burnt odor of the pellets is the burnt odor generated during kneading of the composition. The evaluation results are shown in Table 3.

[0192] <Evaluation Method for Burnt Odor of Pellets>

[0193] Immediately after the pelletizing step, that is, after the low-odor composition ejected from the twin-screw extruder was cooled and cut, three panelists directly smelled the odor of the pellets and sensory-evaluated the burning odor of the pellets.

[0194] The molded articles of Examples 1 to 3, Comparative Example 1, and Reference Example 1 were evaluated for burning odor using the following method. In other words, the burning odor of the molded articles refers to the burning odor generated during molding. The evaluation results are shown in Table 3.

[0195] <Evaluation Method for Burning Odor of Molded Products>

[0196] The molded product was allowed to cool naturally, then sealed in a polyethylene bag and aged for 24 hours at 20°C. After 24 hours, the bag was opened and one panelist immediately smelled the odor inside the bag to evaluate the burning odor of the molded product.

[0197] [Table 3]

[0198] Burnt odor of pellets Burnt odor of molded products Example 1 No burnt odor No burnt odor Example 2 No burnt odor There is a suppressed burnt odor Example 3 No burnt odor There is a suppressed burnt odor Comparative Example 1 There is a suppressed burnt odor There is a burnt smell Reference Example 1 No burnt odor No burnt odor

[0199] [result]

[0200] Examples 1 to 3 contain an alkaline compound as an odor reducing material. Comparative Example 1 does not contain an odor reducing material. Reference Example 1 uses a high-purity cellulose powder that does not contain lignin and / or hemicellulose as lignocellulose fiber.

[0201] Comparison of the evaluation results of Examples 1 to 3 with the evaluation result of Comparative Example 1 reveals that the inclusion of a basic compound as an odor reducing material can suppress the burning odor (see Table 3).

[0202] Furthermore, a comparison of Examples 1 and 2 shows that Example 1 is more effective in suppressing burnt odor (see Table 3). The basic compound used in Example 1 is a strong base, whereas the basic compound used in Example 2 is a weak base. Furthermore, the basic compound used in Example 1 has a larger specific surface area and stronger activity than the basic compound used in Example 2. The results of Examples 1 and 2 demonstrate that using a strong basic compound with a large specific surface area as the basic compound can more effectively suppress burnt odor.

[0203] Furthermore, in Reference Example 1, even though kneading was performed at high temperatures during the composition production (see Table 1), no burning odor was observed in either the pellets or the molded product, compared to Examples 1-3 and Comparative Example 1. This reaffirms that the cause of the burning odor is lignin and / or hemicellulose. Furthermore, the problem of burning odor is less likely to occur in pulp that does not contain lignin and / or hemicellulose, further clarifying that burning odor is an inherent problem of lignocellulosic materials containing these components.

[0204] (Composition of Example 4)

[0205] The same procedures as in Example 1 were performed except that the following adsorbent was used in place of the basic compound.

[0206] Adsorbent: Activated carbon (dry) FUJIFILM Wako Pure Chemical Corporation: 3 parts by mass

[0207] (Composition of Example 5)

[0208] The same procedures as in Example 4 were followed except that the adsorbent material was changed as follows.

[0209] Adsorbent: 6 parts by mass of activated carbon (50% moisture) (FUTAMURACHEMICAL CO., LTD.: Taiko PW) (3 parts by mass of water)

[0210] (Composition of Comparative Example 2)

[0211] The same procedures as in Example 4 were followed except that the adsorbent material was changed as follows.

[0212] Adsorbent: Zeolite (FUJIFILM Wako Pure Chemical Corporation): 3 parts by mass (composition of Comparative Example 3)

[0213] The same procedures as in Example 4 were followed except that the adsorbent material was changed as follows.

[0214] Adsorbent: Diatomaceous earth (Showa Chemical Industry: RADIOLITE SPECIAL FLOW): 3 parts by mass

[0215] (Composition of Comparative Example 4)

[0216] The same procedures as in Example 4 were followed except that the adsorbent material was changed as follows.

[0217] Adsorbent: Activated alumina (FUJIFILM Wako Pure Chemical Corporation: neutral, Super I): 3 parts by mass

[0218] [evaluate]

[0219] The pellets and molded articles of Examples 4 and 5 and Comparative Examples 2 to 4 were evaluated for burning odor by the above-mentioned method. The results are shown in Table 4.

[0220] [Table 4]

[0221] Burnt odor of pellets Burnt odor of molded products Example 4 No burnt odor No burnt odor Example 5 No burnt odor No burnt odor Comparative Example 2 There is a suppressed burnt odor There is a burnt smell Comparative Example 3 There is a suppressed burnt odor There is a burnt smell Comparative Example 4 There is a suppressed burnt odor No burnt odor

[0222] [result]

[0223] Examples 4 and 5 contained activated carbon as the odor reducing material, while Comparative Examples 2 to 4 contained an adsorbent material other than activated carbon.

[0224] Comparison of the evaluation results of Examples 4 and 5 with the evaluation results of Comparative Examples 2 to 4 revealed that the inclusion of activated carbon as an odor reducing material can suppress the burning odor (see Table 4).

[0225] Furthermore, Example 4 used dried activated carbon, whereas Example 5 used hydrous activated carbon containing 50% water by mass. In both Examples 4 and 5, no burning odor was observed in the pellets or molded products, demonstrating that both dried activated carbon and hydrous activated carbon are effective in suppressing burning odors.

[0226] Furthermore, it is clear from Comparative Examples 2 to 4 that sufficient effects of suppressing burning odor are not observed with adsorbents other than activated carbon (see Table 4).

[0227] Lignocellulosic fibers are polar compounds, and the gases generated are generally considered to be primarily polar. However, in Examples 4 and 5, activated carbon, a typical nonpolar porous adsorbent, performed effectively, suggesting that relatively low-polarity phenolic compounds are important as low-threshold burnt odor components. It's not easy to foresee that nonpolar adsorbents would function as adsorbents for gases generated from polar materials like lignocellulosic fibers.

[0228] (Composition of Example 6)

[0229] Resin: Polypropylene (Sumitomo Chemical: Z101A): 63 parts by mass

[0230] Compatibilizing material: Maleic acid-modified polypropylene (Riken Vitamin Co., Ltd.: MG441P) 1 part by mass

[0231] Lignocellulosic fiber: 30 parts by mass

[0232] Adsorbent: 6 parts by mass of activated carbon (50% moisture) (FUTAMURA CHEMICAL CO., LTD.: Taiko PW) (3 parts by mass of water)

[0233] Alkaline compound: magnesium hydroxide (FUJIFILM Wako Pure Chemical Corporation): 3 parts by mass

[0234] [evaluate]

[0235] The pellets and molded articles of Example 6 were evaluated for burning odor by the above-mentioned method. The results are shown in Table 5.

[0236] [Table 5]

[0237] Burnt odor of pellets Burnt odor of molded products Example 6 No burnt odor No burnt odor

[0238] [result]

[0239] Example 6 includes both activated carbon and a basic compound as odor reducing materials.

[0240] From the results of Example 6, it was confirmed that even in the combination of activated carbon and a basic compound, both of them did not exert a negative interference effect and had an effective odor suppressing effect (see Table 5).

[0241] [Recycled materials]

[0242] (Example 7)

[0243] The cycle of kneading, fragmentation, and cooling was repeated five times using the pellets of Example 6. The details of each cycle are as follows.

[0244] <1st cycle>

[0245] The pellets of Example 6 were kneaded using a table-top resin kneading device (LABOPLASTOMILL: Toyo Seiki Seisaku-sho, Ltd.) under the following kneading conditions to obtain a kneaded product.

[0246] <Mixing conditions>

[0247] Mixing temperature: 180℃

[0248] Mixing time: 5 minutes

[0249] Speed: 100RPM

[0250] The obtained kneaded product was finely divided with scissors while it was soft, and cooled with water at 20° C. for 20 seconds.

[0251] <2nd to 4th cycle>

[0252] The cooled fragments obtained in the previous cycle were kneaded under the same kneading conditions as in the first cycle to obtain a kneaded product. The obtained kneaded product was then divided and cooled in the same manner as in the first cycle.

[0253] <5th Cycle>

[0254] The cooled fragments obtained in the previous cycle were kneaded under the same kneading conditions as in the first cycle to obtain a kneaded product.

[0255] [evaluate]

[0256] The kneaded products from the second to fifth cycles were subjected to sensory evaluation for burnt odor. The sensory evaluation was performed by three panelists who directly smelled the odor of the kneaded products immediately after kneading. The results are shown in Table 6.

[0257] [Table 6]

[0258] Example 7 Example 8 Second cycle No burnt odor No burnt odor 3rd cycle No burnt odor No burnt odor 4th cycle No burnt odor No burnt odor 5th cycle Slight burnt smell No burnt odor

[0259] (Example 8)

[0260] Pellets were produced in the same manner as in Example 6, except that 40% water content activated carbon (Futamura Chemical Co., Ltd.: Taiko CB-W) was used as the activated carbon. Using the produced pellets, the kneading, disintegration, and cooling cycles were repeated five times in the same manner as in Example 7. The kneaded products from the second to fifth cycles were then evaluated for burning odor in the same manner as in Example 7. The results are shown in Table 6.

[0261] The results of Examples 7 and 8 confirmed that the generation of burnt odor was effectively suppressed even with repeated pelletization (see Table 6). This indicates that the low-odor composition of the present invention is also effective for the regeneration of resin materials containing lignocellulosic fibers. It should be noted that, taking into account various conditions such as the resin condition, regeneration method, number of regenerations, and compounding composition, the desired effect can naturally be achieved by appropriately adding the low-odor composition of the present invention during the compounding of the recycled material and / or during re-pelletization.

[0262] [Manufacturing of a Composition of Lignocellulosic Fiber, Thermoplastic Resin, and VOC Reducing Material]

[0263] Wood fibers (called thermomechanical pulp or MDF fibers) with radiata pine as the main raw material, thermoplastic resins, and VOC-reducing materials are appropriately blended, and pellets made from the compositions of Examples 9 to 12, Comparative Examples 5 to 11, and Reference Example 2 are manufactured by the manufacturing method of the present embodiment described above. The materials used in the manufacture of each composition are described below. The blending amounts of the materials used in the manufacture of each composition are shown in Table 7. In Table 7, PP represents polypropylene, and MAPP represents maleic acid-modified polypropylene. The set temperatures of each partition when manufacturing the compositions of Examples 9 to 12, Comparative Examples 5 to 11, and Reference Example 2 are the same as those when manufacturing the composition of Example 1, as shown in Table 1.

[0264] [Molded products]

[0265] The pellets of Examples 9 to 12, Comparative Examples 5 to 11, and Reference Example 2 were molded into a flat plate shape of 2 mm in thickness, 100 mm in length, and 100 mm in width using an injection molding machine to produce molded products.

[0266] (Materials for Example 9)

[0267] Resin: Polypropylene (Sumitomo Chemical: Z101A)

[0268] Compatible material: Maleic acid-modified polypropylene (Riken Vitamin Co., Ltd.: MG441P)

[0269] lignocellulosic fibers

[0270] VOC reduction material: Urea (FUJIFILM Wako Pure Chemical Corporation)

[0271] (Materials for Example 10)

[0272] The same procedures as in Example 9 were followed except that the amount of urea added was changed (see Table 7).

[0273] (Materials for Example 11)

[0274] The same procedures as in Example 9 were followed except that the VOC reducing material was changed as follows.

[0275] VOC reduction material: Adipic acid dihydrazide (Tokyo Chemical Industry Co., Ltd.)

[0276] (Materials for Example 12)

[0277] The same procedures as in Example 9 were followed except that the VOC reducing material was changed as follows.

[0278] VOC reduction material: Sebacic acid dihydrazide (Tokyo Chemical Industry Co., Ltd.)

[0279] (Material of Comparative Example 5)

[0280] The same procedures as in Example 9 were employed except that no VOC reducing material was contained.

[0281] (Materials for Reference Example 2)

[0282] The same procedures as in Example 1 were performed except that the VOC reducing material was not contained and cellulose (FUJIFILM Wako Pure Chemical Corporation) was used instead of the lignocellulose fibers.

[0283] (Material of Comparative Example 6)

[0284] The same procedures as in Example 9 were followed except that the VOC reducing material was changed as follows.

[0285] VOC reduction material: BYK-MAX 4200 (BYK)

[0286] (Material of Comparative Example 7)

[0287] The same procedures as in Example 9 were followed except that the VOC reducing material was changed as follows.

[0288] VOC reduction material: BYK-MAX OR4207 (BYK)

[0289] (Material of Comparative Example 8)

[0290] The same procedures as in Example 9 were followed except that the VOC reducing material was changed as follows.

[0291] VOC reduction material: AS757 (Structol)

[0292] (Material of Comparative Example 9)

[0293] The same procedures as in Example 9 were followed except that the VOC reducing material was changed as follows.

[0294] VOC reduction material: AS756 (Structol)

[0295] (Material of Comparative Example 10)

[0296] The same procedures as in Example 9 were followed except that the VVOC reducing material was changed as follows.

[0297] VOC reduction material: Chemcatch TP-6900 (Otsuka Chemical)

[0298] (Material of Comparative Example 11)

[0299] The same procedures as in Example 9 were followed except that the VOC reducing material was changed as follows.

[0300] VOC reduction material: EPOMIN SP-200 (Japan Shokubai)

[0301] [evaluate]

[0302] The molded articles of Examples 9-12, Comparative Examples 5-11, and Reference Example 2 were naturally cooled and then sealed in polyethylene bags. Each molded article was then aged until immediately prior to testing. Various VOC emission concentrations were measured at 65°C using the sampling bag method specified in JASO M902 (2018), "Automotive Parts - Interior Materials - Volatile Organic Compound (VOC) Emissions." The results are shown in Table 7.

[0303] [Table 7]

[0304]

[0305] It should be noted that the indoor concentration guideline values ​​for chemical substances in indoor air are based on (Yakusei Hatsu no. 117001, January 17, 2021) https: / / www.mhlw.go.jp / web / t_doc?dataId=00tc3866&dataType=1&pageNo=1 (confirmed on November 4, 2022). While 13 substances are listed, based on prior test results, the emission values ​​of substances other than formaldehyde and acetaldehyde are below the guideline values ​​even without countermeasures, and therefore have been omitted from the test results.

[0306] [result]

[0307] From the results of Examples 9 and 10, it was confirmed that the acetaldehyde emission concentration gradually decreased as the amount of urea added increased (see Table 7).

[0308] Furthermore, from the results of Examples 11 and 12, it was confirmed that both adipic acid dihydrazide and sebacic acid dihydrazide effectively acted to reduce the concentration of released aldehydes (see Table 7).

[0309] The results of Comparative Example 5 show that the emission concentration of aldehydes is relatively high in the composition containing no VOC reducing material (see Table 7).

[0310] The results of Reference Example 2 indicate that the concentration of acetaldehyde released from high-purity cellulose containing no hemicellulose is relatively low, and that lignocellulosic fibers containing lignin and / or hemicellulose are the source of aldehydes (see Table 7).

[0311] No effect of reducing the concentration of aldehyde release was observed in Comparative Examples 6 and 8 to 11 (see Table 7). However, Comparative Example 11 had a problem in that an odor unique to amines was generated during the kneading and / or molding process.

[0312] The above demonstrates that a resin composition comprising lignocellulosic fibers, which essentially contain lignin and hemicellulose, a resin, and a hydrazide compound serving as a VOC-reducing material effectively reduces the concentration of VOCs emitted from lignocellulosic fibers, regardless of the relatively uneven distribution of lignocellulosic fibers and the VOC-reducing material within the resin or the reaction mechanism. In particular, this composition demonstrates significant effectiveness in reducing the concentration of aldehydes, which are difficult to reduce even at a heating temperature of 65°C (another previously unknown condition) when the VOC concentration increases during sampling.

[0313] [Manufacturing of a Composition of Lignocellulose Fiber, Thermoplastic Resin, Odor Reducing Material, and VOC Reducing Material]

[0314] Wood fiber primarily made from radiata pine (referred to as thermomechanical pulp or MDF fiber) was appropriately blended with a thermoplastic resin, an odor-reducing agent, and a VOC-reducing agent, and pellets were produced using the production method of this embodiment described above. The materials used in the production of the composition are described below. The amounts of the materials used in the production of the composition are shown in Table 8. The set temperatures for each partition during the production of the composition of Example 13 were the same as those used during the production of the composition of Example 1, as shown in Table 1.

[0315] (Materials for Example 13)

[0316] Resin: Polypropylene (Sumitomo Chemical: Z101A)

[0317] Compatible material: Maleic acid-modified polypropylene (Riken Vitamin Co., Ltd.: MG441P)

[0318] Odor reduction materials: Activated carbon (Futamura Chemical Co., Ltd.: Taiko CB-W), magnesium hydroxide (Kanto Chemical)

[0319] VOC reduction material: Adipic acid dihydrazide (Tokyo Chemical Industry Co., Ltd.)

[0320] [evaluate]

[0321] The pellets of Example 13 were evaluated for burnt odor using the above-described method. The results are shown in Table 8. Furthermore, the pellets of Example 13 were measured for VOC emission concentration using the above-described method. The results are shown in Table 8.

[0322] [Table 8]

[0323]

[0324] The results of Example 13 show that even when the odor reducing material and the VOC reducing material are used in combination, there is no negative effect, and both the burnt odor and the VOC emission can be reduced well (see Table 8).

[0325] Industrial applicability

[0326] According to the present invention, it is possible to provide a composition that emits a small amount of burning odor and / or VOC and can be produced at low cost.

Claims

1. A low-odor composition, which is prepared by kneading lignocellulosic fibers containing lignin, a resin, and an odor-reducing material, and is used as a fiber-reinforced resin material. The odor reducing material is either or both of activated carbon and a basic compound.

2. The low-odor composition according to claim 1, wherein The mass ratio of the lignin component in the lignocellulosic fibers is 5% or more and 50% or less.

3. The low-odor composition according to claim 1, wherein The activated carbon is a hydrous activated carbon containing 20% ​​or more and 70% or less of water by mass.

4. The low-odor composition according to claim 1, wherein The activated carbon is a hydrous activated carbon containing 20% ​​to 70% by mass of water, and the water is released as water vapor during kneading of the lignocellulosic fibers, the resin, and the odor-reducing material.

5. The low-odor composition according to claim 1, wherein The basic compound is an inorganic compound.

6. The low-odor composition according to claim 1, wherein The resin is one or more selected from the group consisting of polyethylene, polypropylene, polyvinyl alcohol, polyvinyl acetate, polyethylene oxide, polyvinyl chloride, polystyrene, polylactic acid, polyacetal, polyamides, polyhydroxyalkanes, acrylonitrile-butadiene-styrene copolymers, polyurethanes, modified resins thereof, and copolymeric resins. The low-odor composition according to claim 1 , comprising 1% to 95% of the lignocellulose fibers.

8. A low-VOC resin composition, which is prepared by kneading lignocellulosic fibers containing hemicellulose, a resin, and a VOC-reducing material, and is used as a fiber-reinforced resin material. The VOC reducing material comprises a hydrazide compound.

9. The low VOC resin composition according to claim 8, wherein The VOC reducing material includes a hydrazide compound and a urea compound.

10. The low VOC resin composition according to claim 8, wherein The VOC reducing material reduces VOC derived from lignocellulosic fibers contained in a low-VOC resin composition.

11. The low VOC resin composition according to claim 8, wherein The mass ratio of the hemicellulose component of the lignocellulose fiber is 1% or more and 30% or less.

12. The low VOC resin composition according to claim 8, wherein The hydrazide compound is adipic acid dihydrazide or sebacic acid dihydrazide. 13 . The low-VOC resin composition according to claim 8 , comprising 0.1% by mass or more and 10% by mass or less of the hydrazide compound.

14. The low VOC resin composition according to claim 8, wherein in the JASO M902 test, (1) the formaldehyde emission concentration at a sampling bag heating temperature of 65°C is 100 μg / m 3 The following, or (2) The acetaldehyde release concentration of the sampling bag at a heating temperature of 65°C is 48 μg / m 3 the following.

15. The low VOC resin composition according to claim 8, wherein The resin is one or more selected from the group consisting of polyethylene, polypropylene, polyvinyl alcohol, polyvinyl acetate, polyethylene oxide, polyvinyl chloride, polystyrene, polylactic acid, polyacetal, polyamides, polyhydroxyalkanes, acrylonitrile-butadiene-styrene copolymers, polyurethanes, modified resins thereof, and copolymeric resins. The low-VOC resin composition according to claim 8 , comprising 1% to 95% of the lignocellulose fibers. 17 . A pellet made from the low-odor composition according to claim 1 or the low-VOC resin composition according to claim 8 . 18 . A fiber-reinforced resin material comprising the low-odor composition according to claim 1 or the low-VOC resin composition according to claim 8 . 19 . A molded article comprising the low-odor composition according to claim 1 or the low-VOC resin composition according to claim 8 .

20. A method for producing a low-odor composition, comprising producing the low-odor composition according to any one of claims 1 to 7 using a multi-screw extruder having two or more screws. The multi-screw extruder includes a barrel and a heating device, wherein the barrel has a kneading space in which the screws are arranged, and the heating device includes a plurality of heating parts arranged along the axial direction of the barrel on the outer periphery of the barrel. The method for producing the low-odor composition comprises: A step of melting only the resin or the resin including the lignocellulosic fibers at a temperature above the melting point of the resin; and A step of kneading the lignocellulosic fibers and the melted resin while maintaining the set temperature of the heating section below the melting point of the resin.

21. A method for producing a low-VOC resin composition, comprising producing the low-VOC resin composition according to any one of claims 8 to 16 using a multi-screw extruder having two or more screws. The multi-screw extruder includes a barrel and a heating device, wherein the barrel has a kneading space in which the screws are arranged, and the heating device includes a plurality of heating parts arranged along the axial direction of the barrel on the outer periphery of the barrel. The method for producing the low VOC resin composition comprises: A step of melting only the resin or the resin including the lignocellulosic fibers at a temperature above the melting point of the resin; and A step of kneading the lignocellulosic fibers and the melted resin while maintaining the set temperature of the heating section below the melting point of the resin.

22. A recycled material of a composition of lignocellulosic fibers and resin, The recycled material comprises the low-odor composition according to any one of claims 1 to 7 or the low-VOC resin composition according to any one of claims 8 to 16.

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