Polysaccharide-based resin composition and molded object comprising same

Abstract

Provided are a polysaccharide-based resin composition excellent in terms of flame retardancy, mechanical property, and heat resistance and a molded object comprising the polysaccharide-based resin composition. One embodiment of the polysaccharide-based resin composition according to the present disclosure comprises: component (A) that is a polysaccharide-based resin comprising cellulose and / or paramylon in which at least some of the hydrogen atoms of the hydroxy groups have been replaced by a long-chain component which is a C12 or higher, linear, saturated, aliphatic acyl group and a short-chain component which is a C2 or C3 acyl group; component (B) that is a metal hydroxide; component (C) that is a phosphoric acid ester; component (D) that is glass fiber; and component (E) that is a drip inhibitor. The amount of each of the components (A) to (D) in the composition is within a predetermined range.

Description

Polysaccharide-based resin composition and molded article using the same

[0001] The present disclosure relates to bioplastics, particularly to polysaccharide-based resin compositions and molded articles using the same.

[0002] Bioplastics made from plant components can contribute to combating oil depletion and global warming, and are therefore beginning to be used in durable products such as electronic devices and automobiles, in addition to general products such as packaging, containers, and textiles.

[0003] Bioplastics, such as polylactic acid, polyhydroxyalkanoates, and modified starch, are all made from starch-based materials, i.e., edible parts. Therefore, concerns about future food shortages have led to the development of new bioplastics made from inedible parts.

[0004] A typical raw material for inedible parts is cellulose, a major component of wood and plants, and various bioplastics using this material have been developed and commercialized. Cellulose is obtained by using chemicals to remove the lignin and hemicellulose contained in wood and other materials. Alternatively, cotton, which is composed almost entirely of cellulose, can be used as is. Cellulose is a polymer formed by the polymerization of β-1,4 glucose, but it is not thermoplastic due to the strong intermolecular forces created by hydrogen bonds derived from hydroxyl groups. It also has low solubility in solvents, except for special solvents. Furthermore, due to the large number of hydrophilic hydroxyl groups, it has high water absorption and low water resistance.

[0005] For this reason, the hydrogen atoms of the hydroxyl groups of cellulose are replaced with short-chain acyl groups such as acetyl groups to reduce the intermolecular forces of cellulose, and then a plasticizer is added to impart thermoplasticity. Furthermore, if short-chain organic groups such as acetyl groups alone are insufficient in thermoplasticity and water resistance, long-chain organic groups with a higher carbon number may be introduced into cellulose in addition to the short-chain organic groups. The introduced long-chain organic groups function as hydrophobic internal plasticizers, improving the thermoplasticity and water resistance of cellulose derivatives.

[0006] In addition, algae biomass is attracting attention as a plant source of non-edible components other than cellulose. Algae can be cultivated on land unsuitable for farming, does not compete with food production, and does not produce CO ２ Algae can be cultivated repeatedly using a cyclical system of carbon dioxide, nutrients, and sunlight. This allows for sustainable use as a substitute for fossil fuels. Furthermore, algae can also produce useful organic components, particularly long-chain fatty acids and polysaccharides, which are effective as key components of bioplastics, with high efficiency. One such algae-derived polysaccharide is β-1,3 glucan (paramylon). Paramylon is a glucose polymer characterized by being composed exclusively of β-1,3 bonds. Like cellulose, paramylon has strong intermolecular forces due to hydrogen bonds derived from hydroxyl groups, and is therefore not thermoplastic.

[0007] For this reason, in the case of bioplastics using paramylon, similar to cellulose, paramylon derivatives with thermoplastic properties have been developed by adding acetyl groups or long-chain organic groups to paramylon.

[0008] These plant-derived resins require flame retardancy measures when used in applications requiring high flame retardancy, such as housings for home appliances and office automation equipment. In particular, when a resin composition made from a plant-derived resin is used for the housings of electrical appliances, it is necessary for the resin composition to satisfy flame retardancy standards such as UL94.

[0009] Resin compositions containing flame retardants have been investigated with the aim of improving flame retardancy. For example, Patent Document 1 describes a resin composition containing a β-1,3-glucan derivative resin in which some hydroxyl groups in the glucose constituting β-1,3-glucan are acylated with acyl groups, and a phosphorus-based flame retardant.

[0010] Japanese Patent Application Laid-Open No. 2022-3113

[0011] In order to apply polysaccharide resins such as cellulose resins and paramylon resins to the housings of electronic devices, etc., the resin compositions are required to have excellent heat resistance and mechanical strength in addition to flame retardancy. However, no polysaccharide resin compositions have been obtained that have a good balance of these properties.

[0012] The present invention aims to solve the above problems and to provide a polysaccharide-based resin composition that is excellent in flame retardancy, heat resistance, and mechanical strength, and a molded article formed using the same.

[0013] One aspect of the present disclosure relates to the following.

[0014] A polysaccharide-based resin composition according to one embodiment of the present disclosure comprises: component (A): (A1) at least one polysaccharide-based resin selected from the group consisting of cellulose-based resins in which at least a portion of the hydrogen atoms of hydroxy groups of cellulose have been substituted with a long-chain component which is a linear saturated aliphatic acyl group having 12 or more carbon atoms and a short-chain component which is an acyl group having 2 or 3 carbon atoms, and (A2) paramylon-based resins in which at least a portion of the hydrogen atoms of hydroxy groups of paramylon have been substituted with a long-chain component which is a linear saturated aliphatic acyl group having 12 or more carbon atoms and a short-chain component which is an acyl group having 2 or 3 carbon atoms; component (B): a metal hydroxide; component (C): a phosphate ester; component (D): glass fiber; and component (E): an anti-drip agent, wherein the content of component (A) is 20 to 50% by mass, and the content of component (B) is 35 to 50% by mass, relative to 100% by mass of the total content of components (A) to (E). The content of component (C) is 1.9% by mass to 10% by mass, and the content of component (D) is 8% by mass to 27% by mass.

[0015] According to the present disclosure, it is possible to provide a polysaccharide-based resin composition having excellent flame retardancy, mechanical strength, and heat resistance, and a molded article molded using the same.

[0016] In one embodiment, the polysaccharide-based resin composition (also simply referred to as "resin composition") of the present disclosure comprises: Component (A): (A1) at least one polysaccharide-based resin selected from the group consisting of cellulose-based resins in which at least a portion of the hydrogen atoms of hydroxy groups of cellulose have been substituted with a long-chain component which is a linear saturated aliphatic acyl group having 12 or more carbon atoms and a short-chain component which is an acyl group having 2 or 3 carbon atoms (acetyl group and / or propionyl group), and (A2) paramylon-based resins in which at least a portion of the hydrogen atoms of hydroxy groups of paramylon have been substituted with a long-chain component which is a linear saturated aliphatic acyl group having 12 or more carbon atoms and a short-chain component which is an acyl group having 2 or 3 carbon atoms (acetyl group and / or propionyl group); Component (B): a metal hydroxide; Component (C): a phosphate ester; Component (D): glass fiber; Component (E): an anti-drip agent; With respect to 100% by mass of the total content of components (A) to (E), the content of component (A) is 20 to 50% by mass, the content of component (B) is 35 to 50% by mass, the content of component (C) is 1.9% to 10% by mass, and the content of component (D) is 8 to 27% by mass.

[0017] In the past, there was a problem that the use of a highly safe inorganic flame retardant in a polysaccharide-based resin composition resulted in a decrease in toughness. Furthermore, there was a problem that the use of a phosphate ester as both a plasticizer and a flame retardant in a polysaccharide-based resin composition resulted in poor heat resistance. The polysaccharide-based resin composition of the present disclosure solves these problems and can form a molded article that has excellent thermoplasticity, flame retardancy, mechanical properties (flexural strength, flexural modulus, flexural strain at break, etc.), and heat resistance. Each component will be described below.

[0018] <Component (A): Polysaccharide Resin> The polysaccharide resin composition of the present disclosure contains, as component (A), at least one polysaccharide resin (also referred to as a "polysaccharide derivative" or "polysaccharide derivative") selected from the group consisting of (A1) a cellulose resin in which at least some of the hydrogen atoms of hydroxy groups of cellulose have been substituted with a long-chain component that is a linear saturated aliphatic acyl group having 12 or more carbon atoms and a short-chain component that is an acyl group having 2 or 3 carbon atoms (also referred to as "component (A1)"), and (A2) a paramylon resin in which at least some of the hydrogen atoms of hydroxy groups of paramylon have been substituted with a long-chain component that is a linear saturated aliphatic acyl group having 12 or more carbon atoms and a short-chain component that is an acyl group having 2 or 3 carbon atoms (also referred to as "component (A2)"). Note that, in this specification, cellulose resins are also referred to as "cellulose derivatives," and paramylon resins are also referred to as "paramylon derivatives." The component (A) may contain at least one of the components (A1) and (A2), or may contain both.

[0019] (Component (A1): Cellulose-Based Resin) The cellulose-based resin (cellulose derivative) (A1) is a cellulose-based resin in which at least some of the hydrogen atoms of the hydroxy groups of cellulose are substituted with long-chain components that are linear saturated aliphatic acyl groups having 12 or more carbon atoms and short-chain components that are acyl groups having 2 or 3 carbon atoms (acetyl groups and / or propionyl groups).

[0020] (Cellulose) Cellulose is a linear polymer formed by the polymerization of β-D-glucose molecules (β-D-glucopyranose) via β(1→4) glycosidic bonds, as shown in the following formula (1). Each glucose unit constituting cellulose has three hydroxy groups (n in the formula is a natural number). In one aspect of the present disclosure, such cellulose is used in which organic groups such as acyl groups (long-chain components and short-chain components) are introduced into the cellulose by utilizing these hydroxy groups.

[0021]

[0022] Cellulose is a major component of plants and can be obtained by separating other components such as lignin from plants. In addition to those obtained in this way, cotton (e.g., cotton linters) and pulp (e.g., wood pulp) with a high cellulose content can be used either as is or after purification. Regarding the shape, size, and form of cellulose or its derivatives used as raw materials, it is preferable to use cellulose or its derivatives in powder form with an appropriate particle size and shape in terms of reactivity, solid-liquid separation, and handleability. For example, fibrous or powdery materials with a diameter of 1 to 100 μm (preferably 10 to 50 μm) and a length of 10 μm to 100 mm (preferably 100 μm to 10 mm) can be used.

[0023] The degree of polymerization of cellulose, in terms of glucose polymerization degree (average polymerization degree), is preferably 50 or more, more preferably 100 or more, even more preferably 500 or more, and is preferably 5000 or less, more preferably 3000 or less. The degree of polymerization of cellulose, in terms of glucose polymerization degree (average polymerization degree), is preferably in the range of 50 to 5000, more preferably 100 to 3000, and even more preferably 500 to 3000. If the degree of polymerization is too low, the strength, heat resistance, etc. of the produced resin may be insufficient. Conversely, if the degree of polymerization is too high, the melt viscosity of the produced resin may become too high, causing problems in molding.

[0024] The degree of polymerization of this cellulose (before the introduction of long-chain and short-chain components) was calculated by measuring the intrinsic viscosity [η] in accordance with JIS P8215 and using the following formula: [η] = 1.67 × DP ０．７１

[0025] (Long Chain Component) The long chain component of the cellulose-based resin (cellulose derivative) in the present disclosure is a linear saturated aliphatic acyl group having 12 or more carbon atoms, and can be introduced by utilizing the hydroxy group of cellulose.

[0026] Long-chain components can be introduced by reacting hydroxy groups in cellulose with a long-chain reactant. This long-chain component corresponds to an acyl group introduced in place of a hydrogen atom of a hydroxy group in cellulose. The long-chain organic group of the long-chain component and the pyranose ring of cellulose can be bonded via an ester bond. The introduced acyl group is preferably a linear saturated aliphatic acyl group having 12 or more carbon atoms, more preferably 14 or more carbon atoms. In one embodiment, the long-chain component is a linear saturated aliphatic acyl group, such as a linear saturated aliphatic acyl group having 12 to 30 carbon atoms, preferably a linear saturated aliphatic acyl group having 12 to 22 carbon atoms, and more preferably a group formed by removing an OH group from the carboxyl group of lauric acid (dodecanoic acid), myristic acid, palmitic acid, stearic acid, arachidic acid, or behenic acid (dodecanoyl group, tetradecanoyl group, hexadecanoyl group, octadecanoyl group, icosanoyl group, or docosanoyl group). The long chain component may be one type alone or may contain two or more types.

[0027] The long-chain reactant is a compound having at least one functional group capable of reacting with a hydroxy group in cellulose, and for example, a compound having a carboxyl group, a carboxylic acid halide group, or a carboxylic acid anhydride group can be used.

[0028] Examples of long-chain reactants include long-chain carboxylic acids having 12 or more carbon atoms, and acid halides or acid anhydrides of such long-chain carboxylic acids. It is desirable that these carboxylic acids or carboxylic acid derivatives have as high a degree of saturation as possible, and straight-chain saturated fatty acids and their acid halides or anhydrides are preferred. Specific examples of long-chain carboxylic acids include straight-chain saturated fatty acids such as lauric acid (dodecanoic acid), myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, and melissic acid, with lauric acid (dodecanoic acid), myristic acid, palmitic acid, stearic acid, arachidic acid, and behenic acid being preferred. Furthermore, from the standpoint of environmental friendliness, carboxylic acids obtained from natural products may be preferred as long-chain carboxylic acids.

[0029] The long-chain component preferably has 12 or more carbon atoms. From the viewpoint of reaction efficiency when the long-chain component is introduced, the long-chain component preferably has 48 or less carbon atoms, more preferably 36 or less carbon atoms, even more preferably 24 or less carbon atoms, and particularly preferably 22 or less carbon atoms. The long-chain component may be one type alone, or may contain two or more types.

[0030] The average number of long chain components introduced per glucose unit of cellulose (DS ＬＯ ) (long-chain component introduction ratio), i.e., the average number of hydroxy groups substituted with long-chain components (straight-chain saturated aliphatic acyl groups having 12 or more carbon atoms) per glucose unit (hydroxyl group substitution degree), can be appropriately set depending on the structure and amount of short-chain components introduced, the structure of long-chain components, the physical properties required for the target product, and the efficiency during production, and can be set in the range of, for example, 0.1 to 2.9. ＬＯ is preferably 0.2 or more, more preferably 0.3 or more, and from the viewpoints of production efficiency and durability (strength, heat resistance, etc.), is preferably 2.0 or less, more preferably 1.5 or less, and even more preferably 1.0 or less. In particular, from the viewpoint of durability (strength, heat resistance, etc.), DS ＬＯ is preferably 0.6 or less, more preferably 0.5 or less, and in some cases even more preferably 0.4 or less.

[0031] By introducing the above-mentioned long chain components into cellulose or its derivatives, the properties thereof can be modified, for example, water resistance, thermoplasticity, and mechanical properties can be improved.

[0032] (Short-chain components) The cellulose-based resin is preferably one in which short-chain components are introduced in addition to long-chain components by utilizing the hydroxyl groups of cellulose. The short-chain components are preferably acetyl groups and / or propionyl groups, and preferably contain at least a propionyl group, with a propionyl group being particularly preferred.

[0033] Such short-chain components can be introduced by reacting hydroxyl groups in cellulose with a short-chain reactant. The short-chain components correspond to acyl groups introduced in place of hydrogen atoms in the hydroxyl groups of cellulose. The short-chain organic groups (methyl or ethyl groups) of the short-chain components can be bonded to the pyranose rings of cellulose via ester bonds.

[0034] The short-chain reactant is a compound having at least one functional group capable of reacting with the hydroxyl group in cellulose, such as a compound having a carboxyl group, a carboxylic acid halide group, or a carboxylic acid anhydride group. Specific examples include aliphatic monocarboxylic acids, their acid halides, and their acid anhydrides.

[0035] This short-chain component preferably has 2 to 3 carbon atoms, more preferably 3 carbon atoms, and the hydrogen atom of the hydroxy group of cellulose is preferably replaced by an acyl group having 2 to 3 carbon atoms (acetyl group, propionyl group), more preferably by an acyl group having at least 3 carbon atoms (propionyl group).

[0036] The average number of acyl groups with 2 or 3 carbon atoms introduced per glucose unit of cellulose (DS ＳＨ ) (short chain component introduction ratio), i.e., the average number of hydroxy groups substituted with short chain components per glucose unit (hydroxyl group substitution degree), can be set in the range of 0.1 to 2.9. In order to fully obtain the effect of introducing short chain components, particularly from the viewpoints of water resistance, flowability, etc., DS ＳＨ is preferably 1.7 or more, more preferably 1.9 or more, and even more preferably 2.0 or more. From the viewpoint of obtaining the effect of introducing short chain components while fully obtaining the effect of long chain components and other groups (hydroxyl group, etc.), DS ＳＨ is preferably 2.8 or less, more preferably 2.7 or less, and even more preferably 2.6 or less.

[0037] By introducing the above-mentioned short-chain components into cellulose, the intermolecular forces (intermolecular bonds) of cellulose can be reduced, and plasticity can be improved.

[0038] In cellulose-based resins, the ratio of short chain components to long chain components (DS ＳＨ / DS ＬＯ ) is not limited, but is preferably 4 or more and 12 or less. When this ratio is 4 or more and is appropriately large, the material tends to be appropriately flexible and have sufficient strength and heat resistance, and when it is 12 or less and is appropriately small, sufficient thermoplasticity is obtained and the material tends to be suitable for molding applications.

[0039] (Residual Amount of Hydroxy Groups) The greater the residual amount of hydroxy groups, the greater the maximum strength and heat resistance of the cellulose-based resin, but the greater the water absorption. On the other hand, the higher the conversion rate (degree of substitution) of the hydroxy groups, the lower the water absorption and the greater the plasticity and bending fracture strain, but the lower the maximum strength and heat resistance. Taking these trends into consideration, the conversion rate of the hydroxy groups can be appropriately set.

[0040] The average number of remaining hydroxyl groups per glucose unit of the cellulose-based resin (hydroxyl group residual degree) can be set, for example, in the range of 0 to 2.9. Hydroxy groups may remain from the viewpoint of maximum strength, heat resistance, etc., and, for example, the hydroxyl group residual degree may be 0.01 or more, or even 0.1 or more. In particular, from the viewpoint of fluidity, the hydroxyl group residual degree of the final cellulose-based resin is preferably 1.0 or less, more preferably 0.8 or less, and particularly preferably 0.6 or less. Furthermore, from the viewpoint of water resistance, impact resistance, etc. in addition to fluidity, the hydroxyl group residual degree may be preferably 0.6 or less, more preferably 0.5 or less, even more preferably 0.4 or less, and particularly preferably 0.2 or less.

[0041] (Component (A2): Paramylon-based resin) Paramylon-based resin is a paramylon derivative in which at least some of the hydrogen atoms of the hydroxy groups of paramylon are substituted with long-chain components that are linear saturated aliphatic acyl groups having 12 or more carbon atoms, and short-chain components that are acyl groups (acetyl and / or propionyl groups) having 2 or 3 carbon atoms. The long-chain components are preferably linear saturated aliphatic acyl groups having 12 or more carbon atoms.

[0042] (Paramylon) First, the paramylon (before the introduction of long-chain components and short-chain components) used in the production of paramylon-based resins will be described.

[0043] Paramylon is a linear polymer formed by the polymerization of β-D-glucose molecules (β-D-glucopyranose) via β(1→3) glycosidic bonds, as shown in the following formula (101). Each glucose unit that constitutes paramylon has three hydroxyl groups (n in the formula is a natural number). These hydroxyl groups can be used to introduce short-chain organic groups (short-chain components) and long-chain organic groups (long-chain components) into such paramylon.

[0044]

[0045] Paramylon is a major component of algae (particularly Euglena). Paramylon is a polysaccharide accumulated in Euglena as a storage polysaccharide and is stored or consumed as an energy source depending on environmental factors such as nutritional conditions. Euglena from which paramylon is extracted may be cultured under photosynthetic conditions or heterotrophically in a medium supplemented with a carbon source. Cultivating Euglena under photosynthetic conditions allows it to grow while incorporating carbon dioxide into the cells, thereby offering the advantage of being able to immobilize atmospheric carbon dioxide. Furthermore, culturing Euglena under heterotrophic conditions reduces the amount of chlorophyll required for photosynthesis, resulting in a decrease in the amount of pigment and increased transparency of molded paramylon-based resins. The weight-average molecular weight of paramylon (before the hydrolysis process described below) measured by GPC is not particularly limited, but is approximately 220,000 to 470,000, preferably 310,000 to 470,000.

[0046] Although not limited, paramylon-based resins are preferably those containing paramylon having a weight-average molecular weight (Mw) in the range of 70,000 to 440,000, with long-chain and short-chain components introduced via the hydroxyl groups of the paramylon. The Mw of the paramylon may be preferably 100,000 or more, more preferably 120,000 or more, and may be 360,000 or less, more preferably 220,000 or less, and even more preferably 180,000 or less. If the weight-average molecular weight of the paramylon is too low, the resulting resin may have excessive thermoplasticity, which may interfere with molding. On the other hand, if the weight-average molecular weight is too high, the resulting resin may have high heterogeneity and insufficient bending strain at break. Furthermore, if the weight-average molecular weight is too high, the resulting resin may have insufficient thermoplasticity, which may interfere with molding. The molecular weight of the paramylon can be controlled by the hydrolysis conditions in the acid or alkali hydrolysis step. Examples of the acid or alkali used in the hydrolysis step include hydrochloric acid, sulfuric acid, water-soluble organic acids (formic acid, acetic acid, propionic acid, oxalic acid, malonic acid, succinic acid, glycolic acid, lactic acid, etc.), sodium hydroxide, and potassium hydroxide.

[0047] In one embodiment, the molecular weight distribution of paramylon (weight average molecular weight / number average molecular weight) is preferably 6.5 or less, more preferably 6.3 or less, and even more preferably 6.0 or less, with the lower limit preferably being 2.0 or more. Having a molecular weight distribution of paramylon of 6.5 or less makes it easier to obtain a highly homogeneous paramylon-based resin. The number average molecular weight (Mn) of paramylon is not particularly limited, but is preferably 30,000 to 130,000, for example.

[0048] The weight-average molecular weight and number-average molecular weight of paramylon were measured by GPC (gel permeation chromatography) under the following conditions.

[0049] (GPC measurement conditions for paramylon) Column: PLgel 20 μm MIXED-A (product name, manufactured by Agilent Technologies, Inc.) Eluent: dimethylacetamide (DMAc) solution (0.1 M LiCl) Flow rate: 0.5 mL / min Detector: RI (differential refractive index) (RI-71 manufactured by Tosoh Corporation) Temperature: 23.0° C. Standard sample: Pullulan standard

[0050] (Paramylon-based resin) A paramylon-based resin is a paramylon-based resin in which the hydrogen atoms of the hydroxy groups of the paramylon are substituted with a long-chain component that is a linear saturated aliphatic acyl group having 12 or more carbon atoms, and a short-chain component that is an acyl group (acetyl group or propionyl group) having 2 or 3 carbon atoms. In one embodiment, the short-chain component is preferably a propionyl group.

[0051] (Long-chain components) Long-chain components can be introduced by reacting hydroxyl groups in paramylon with a long-chain reactant. This long-chain component corresponds to an acyl group introduced in place of the hydrogen atom of the hydroxyl group of paramylon. The long-chain organic group of the long-chain component and the pyranose ring of paramylon can be bonded via an ester bond. This introduced acyl group is preferably a linear saturated aliphatic acyl group with 12 or more carbon atoms, more preferably 14 or more carbon atoms. The above-mentioned explanations of the long-chain components and long-chain reactants for cellulose-based resins can be applied to the long-chain components and long-chain reactants, and it is possible to introduce long-chain components and use long-chain reactants similar to those for cellulose-based resins.

[0052] The average number of long chain components introduced per glucose unit of paramylon (DS ＬＯ ) (long-chain component introduction ratio), i.e., the average number of hydroxy groups substituted with long-chain components (straight-chain saturated aliphatic acyl groups having 12 or more carbon atoms) per glucose unit (hydroxyl group substitution degree), can be appropriately set depending on the structure and amount of short-chain components introduced, the structure of long-chain components, the physical properties required for the target product, and the efficiency during production, and can be set in the range of, for example, 0.1 to 2.9. ＬＯis preferably 0.2 or more, more preferably 0.3 or more, and from the viewpoints of production efficiency and durability (strength, heat resistance, etc.), is preferably 2.0 or less, more preferably 1.5 or less, and even more preferably 1.0 or less. In particular, from the viewpoint of durability (strength, heat resistance, etc.), DS ＬＯ is preferably 0.6 or less, more preferably 0.5 or less, and in some cases is particularly preferably 0.4 or less.

[0053] By introducing the above-mentioned long-chain components into paramylon or its derivatives, its properties can be modified, for example, improving water resistance, thermoplasticity, and mechanical properties.

[0054] (Short-chain components) The paramylon-based resin preferably has short-chain components introduced in addition to long-chain components by utilizing the hydroxyl groups of paramylon. The short-chain components are preferably acetyl groups and / or propionyl groups, and preferably contain at least propionyl groups, with propionyl groups being particularly preferred.

[0055] Such short-chain components can be introduced by reacting hydroxyl groups in paramylon with short-chain reactants. These short-chain components correspond to acyl groups introduced in place of hydrogen atoms in the hydroxyl groups of paramylon. The short-chain organic groups (methyl or ethyl groups) of the short-chain components can be bonded to the pyranose rings of paramylon via ester bonds. The above-mentioned descriptions of the short-chain components and short-chain reactants for cellulose-based resins can be applied to the short-chain components and short-chain reactants, and the introduction of short-chain components and the use of short-chain reactants similar to those for cellulose-based resins are possible.

[0056] The average number of acyl groups with 2 or 3 carbon atoms introduced per glucose unit of paramylon (DS ＳＨ ) (short chain component introduction ratio), i.e., the average number of hydroxy groups substituted with short chain components per glucose unit (hydroxyl group substitution degree), can be set in the range of 0.1 to 2.9. In order to fully obtain the effect of introducing short chain components, particularly from the viewpoints of water resistance, flowability, etc., DS ＳＨis preferably 1.9 or more, more preferably 2.0 or more, and even more preferably 2.1 or more. From the viewpoint of obtaining the effect of introducing short chain components while fully obtaining the effect of long chain components and other groups (hydroxyl groups, etc.), DS ＳＨ is preferably 2.8 or less, more preferably 2.7 or less, and even more preferably 2.6 or less.

[0057] By introducing the above-mentioned short-chain components into paramylon, the intermolecular forces (intermolecular bonds) of paramylon can be reduced, thereby improving its plasticity.

[0058] In paramylon-based resins, the ratio of short chain components to long chain components (DS ＳＨ / DS ＬＯ ) is preferably 5 or more and 25 or less. When this ratio is 5 or more and is moderately large, the material tends to be moderately flexible and have sufficient strength and heat resistance, and when it is 25 or less and is moderately small, sufficient thermoplasticity is obtained, making it suitable for molding applications. In one aspect, paramylon-based resins tend to be more thermoplastic than cellulose-based resins, so the range of the ratio of short-chain components to long-chain components can be wider than that of cellulose-based resins.

[0059] (Residual Amount of Hydroxy Groups) The greater the residual amount of hydroxy groups, the greater the maximum strength and heat resistance of the paramylon-based resin, but the greater the water absorption. On the other hand, the higher the conversion rate (degree of substitution) of hydroxy groups, the lower the water absorption and the greater the plasticity and bending fracture strain, but the lower the maximum strength and heat resistance. Taking these trends into consideration, the conversion rate of hydroxy groups can be appropriately set.

[0060] The average number of remaining hydroxyl groups per glucose unit of the paramylon-based resin (residual hydroxyl group degree) can be set, for example, in the range of 0 to 2.9. Hydroxy groups may remain from the viewpoint of maximum strength, heat resistance, etc., and the residual hydroxyl group degree may be, for example, 0.3 or more, or even 0.4 or more. In particular, from the viewpoint of water resistance in addition to fluidity, the residual hydroxyl group degree of the final paramylon-based resin is preferably 1.0 or less, and particularly preferably 0.8 or less.

[0061] (Method for producing polysaccharide-based resins (cellulose-based resins and paramylon-based resins)) The cellulose-based resins and paramylon-based resins (also referred to as "polysaccharide-based resins") used in the present disclosure can be produced, for example, by the following production method. Hereinafter, cellulose and paramylon will also be referred to as "polysaccharides."

[0062] (Activation of Polysaccharides) Before the reaction step for introducing long-chain components and short-chain components into polysaccharides (cellulose and / or paramylon), an activation treatment (pretreatment step) can be carried out to increase the reactivity of the polysaccharides. This activation treatment can be the same as the activation treatment usually carried out before acetylation of polysaccharides.

[0063] Activation treatments can be performed using wet methods, such as spraying an activating solvent compatible with the polysaccharide onto the polysaccharide or immersing the polysaccharide in the activating solvent (immersion method), to bring the polysaccharide into contact with the solvent and swell the polysaccharide. This facilitates penetration of the reactant between the polysaccharide molecular chains (or, if a solvent or catalyst is used, facilitates penetration along with the solvent or catalyst), thereby improving the reactivity of the polysaccharide. Examples of activating solvents include water; carboxylic acids such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, and stearic acid; alcohols such as methanol, ethanol, propanol, and isopropanol; nitrogen-containing compounds such as dimethylformamide, formamide, ethanolamine, and pyridine; and sulfoxide compounds such as dimethyl sulfoxide. These may be used alone or in combination. Water, acetic acid, pyridine, and dimethyl sulfoxide are particularly preferred.

[0064] Activation can also be carried out by adding a polysaccharide to the long-chain fatty acid. If the melting point of the long-chain fatty acid is room temperature or higher, the long-chain fatty acid can be heated to a temperature above the melting point.

[0065] The amount of the activating solvent used can be set to, for example, 10 parts by mass or more, preferably 20 parts by mass or more, and more preferably 30 parts by mass or more, relative to 100 parts by mass of the polysaccharide. When the polysaccharide is immersed in the activating solvent, the amount can be set to, for example, 1 time or more, preferably 5 times or more, and more preferably 10 times or more, relative to the polysaccharide. From the viewpoints of the burden of removing the activating solvent after pretreatment and reducing material costs, the amount of the activating solvent used is, for example, preferably 300 times or less, more preferably 100 times or less, and even more preferably 50 times or less, relative to 100 parts by mass of the polysaccharide.

[0066] The temperature of the activation treatment can be appropriately set, for example, in the range of 0 to 100° C. From the viewpoint of activation efficiency and reducing energy costs, the temperature of the activation treatment is preferably 10 to 40° C., more preferably 15 to 35° C.

[0067] When the polysaccharide is added to the melted long-chain fatty acid, the mixture can be heated to a temperature equal to or higher than the melting point of the long-chain fatty acid.

[0068] The activation treatment time can be set appropriately within the range of, for example, 0.1 to 72 hours. From the viewpoint of performing sufficient activation and reducing the treatment time, the activation treatment time is preferably 0.1 to 24 hours, and more preferably 0.5 to 3 hours.

[0069] After the activation treatment, excess activation solvent can be removed by a solid-liquid separation method such as suction filtration, filter press, or squeezing.

[0070] After the activation treatment, the activation solvent contained in the polysaccharide can be replaced with the solvent used in the reaction. For example, the replacement treatment can be carried out by the immersion method of the activation treatment described above, except that the activation solvent is replaced with the solvent used in the reaction.

[0071] (Method for introducing long-chain components and short-chain components) The polysaccharide derivative (polysaccharide resin) according to the present disclosure can be produced by the method shown below.

[0072] In one embodiment, a method for producing a polysaccharide derivative includes a step of reacting a polysaccharide dispersed in a solvent with a short-chain reactant (short-chain acylating agent) and a long-chain reactant (long-chain acylating agent) under heating in a solvent in the presence of an acid scavenger component to acylate the hydroxy groups of the polysaccharide. The short-chain reactant (short-chain acylating agent) and the long-chain reactant (long-chain acylating agent) are preferably dissolved in the solvent. The acid scavenger component can also be used as the solvent.

[0073] The long-chain reactant for introducing long-chain components into polysaccharides is preferably an acid chloride of the aforementioned saturated fatty acid (preferably an acid chloride of a linear saturated fatty acid), and may be used alone or in combination of two or more. Examples of long-chain reactants include long-chain carboxylic acids having 12 or more carbon atoms, and acid halides or acid anhydrides of such long-chain carboxylic acids. It is desirable that these carboxylic acids or carboxylic acid derivatives have as high a degree of saturation as possible, and linear saturated fatty acids, their acid halides (preferably acid chlorides), or anhydrides are preferred. Specific examples of long-chain carboxylic acids include linear saturated fatty acids such as lauric acid (dodecanoic acid), myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, and melissic acid. Lauric acid (dodecanoic acid), myristic acid, palmitic acid, stearic acid, arachidic acid, and behenic acid are preferred. As a short-chain reactant for introducing short-chain components into polysaccharides, acetyl chloride and / or propionyl chloride is preferred, and propionyl chloride is more preferred.

[0074] The amounts of the long-chain reactant and the short-chain reactant to be added are determined based on the degree of substitution (DS) of the desired polysaccharide derivative with long-chain components. Ｌｏ ) and the degree of substitution by short chain components (DS Ｓｈ In one embodiment, if the amount of the short chain reactant is too large, the amount of the long chain component bonded decreases, and the degree of substitution by the long chain component (DS Ｌｏ ) may decrease.

[0075] As the solvent, a solvent that can retain 90% or more by volume of the liquid in a cotton fiber filter paper can be used.

[0076] The "liquid retention rate" can be measured by the following method. Cotton fiber filter paper (5B, 40 mm diameter, moisture content approximately 2%) is immersed in each solvent at room temperature for 1 hour. The weight is measured before and after immersion, and the liquid retention rate (vol%) is calculated using the formula below. After immersion, the weight is measured when the solvent stops dripping from the sample.

[0077] Liquid retention rate (vol%)=(weight after immersion−weight before immersion) / weight before immersion / specific gravity of solvent×100

[0078] Examples of solvents that achieve a liquid retention rate of 90 vol% or more by the above method include water (liquid retention rate 145 vol%), acetic acid (liquid retention rate 109 vol%), dioxane (liquid retention rate 93 vol%), pyridine (liquid retention rate 109 vol%), N-methylpyrrolidone (liquid retention rate 104 vol%), N,N-dimethylacetamide (liquid retention rate 112 vol%), N,N-dimethylformamide (liquid retention rate 129 vol%), and dimethyl sulfoxide (liquid retention rate 180 vol%).

[0079] The acid scavenger component is not particularly limited as long as it is a base that neutralizes by-produced acids (such as hydrochloric acid, acetic acid, and propionic acid). Examples include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; alkaline earth metal hydroxides such as calcium hydroxide and barium hydroxide; metal alkoxides such as sodium methoxide and sodium ethoxide; and nitrogen-containing nucleophilic compounds such as diazabicycloundecene, diazabicyclononene, triethylamine, and pyridine. Among these, triethylamine and pyridine are preferred, and pyridine is particularly preferred because it can also be used as a solvent. When the acid scavenger component is added separately from the solvent, it is preferable that the acid scavenger component be present in the reaction system from the start of the reaction. As long as the acid scavenger component is present in the reaction system at the start of the reaction, it does not matter whether the acid scavenger component is added before or after the addition of the acylating agent.

[0080] The amount of the acid scavenger component added is preferably 0.1 to 10 equivalents, more preferably 0.5 to 5 equivalents, relative to the total amount of the long-chain reactant (long-chain acylating agent) and short-chain reactant (short-chain acylating agent) charged. However, this range is not limited when a nitrogen-containing nucleophilic compound is used as a solvent. If the amount of the acid scavenger added is too small, the efficiency of the acylation reaction may decrease. Furthermore, if the amount of the acid scavenger added is too large, the polysaccharide may decompose, resulting in a decrease in molecular weight.

[0081] The reaction temperature in this acylation step is preferably 50 to 100°C, more preferably 75 to 95°C. The reaction time is not limited, but can be set to 1 to 10 hours, and may preferably be set to 3 to 6 hours. If the reaction temperature is sufficiently high, the reaction rate can be increased, allowing the acylation reaction to be completed in a relatively short time, thereby increasing the reaction efficiency. Furthermore, if the reaction temperature is within the above range, it is possible to suppress a decrease in molecular weight due to heating.

[0082] The amount of the solvent can be set to 10 to 50 times the dry mass of the raw material polysaccharide, preferably 10 to 40 times, and more preferably 20 to 40 times (mass ratio).

[0083] In one embodiment, after the acylation step, an alkaline aqueous solution is added and the mixture is maintained under heating (aging). The aging temperature is preferably 25 to 75° C., and more preferably 40 to 70° C. The aging time can be set in the range of 1 to 5 hours, and more preferably 1 to 3 hours.

[0084] The amount of the alkaline aqueous solution added can be set to an amount equivalent to 3 to 30% by mass, preferably 5 to 20% by mass, based on the amount of the solvent used.

[0085] Examples of the alkaline aqueous solution include aqueous solutions of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, etc., and an aqueous solution of sodium hydroxide is preferred. The concentration of the alkaline aqueous solution is, for example, preferably 1 to 30% by mass, more preferably 5 to 20% by mass.

[0086] This aging process partially hydrolyzes the long-chain and short-chain components that have been bonded together, allowing the hydroxyl groups to be uniformly restored, improving mechanical properties such as strength and impact resistance, and enabling the subsequent precipitation process to produce a product with good properties (fine particles).

[0087] (Recovery Step) The polysaccharide derivative (product) into which long-chain components and short-chain components have been introduced can be recovered from the reaction solution by a conventional recovery method, and the method is not limited thereto. However, if the product is not dissolved in the reaction solution, a recovery method in which the reaction solution and the product are subjected to solid-liquid separation is preferred from the viewpoint of production energy. If the product dissolves in or has an affinity with the reaction solution, making solid-liquid separation difficult, the reaction solution can be distilled off and the product recovered as a residue. Alternatively, a poor solvent for the product can be added to the reaction solution, and the precipitated product can be recovered by solid-liquid separation.

[0088] When the reaction solution is distilled off, it is preferable that the short-chain reactant, reaction solvent, and catalyst have low boiling points, but the catalyst can also be removed from the product without distilling off using a wash solvent, etc. Furthermore, when components other than the product, such as the solvent, are distilled off from the reaction solution, the distillation can be stopped when the product precipitates, and then the remaining reaction solution and the precipitated product can be subjected to solid-liquid separation to recover the product.

[0089] Examples of solid-liquid separation methods include filtration (natural filtration, reduced pressure filtration, pressure filtration, centrifugal filtration, and hot filtration of these), natural sedimentation / floating, liquid separation, centrifugal separation, squeezing, etc., and these may be used in appropriate combinations.

[0090] The product (polysaccharide derivative) dissolved in the filtrate after solid-liquid separation can be precipitated by adding a poor solvent for the product, and can be recovered by further solid-liquid separation.

[0091] The solid matter (polysaccharide derivative) recovered from the reaction solution can be washed as needed and dried by a conventional method.

[0092] The polysaccharide derivatives produced by this method can have a reinforced crystalline structure due to polysaccharide main chain crystals within a thermoplastic matrix. This is due to the unreacted portion of the polysaccharide raw material acylated. Such polysaccharide main chain crystals can be evaluated, for example, by X-ray diffraction. During this evaluation, the polysaccharide derivative can be pressed to increase its density, making it easier to confirm the signal.

[0093] (Other methods for producing polysaccharide derivatives) In one embodiment, a polysaccharide resin can be obtained by acylation of a polysaccharide in a solid-liquid heterogeneous system using a mixed acid anhydride having a long-chain component and a short-chain component as an acylating agent. The polysaccharide is preferably subjected to an activation treatment. The activation treatment can be carried out by a conventional method.

[0094] Acylation can be carried out by stirring in a solvent (e.g., dioxane, for example, in an amount 80 to 120 times the weight of the dried polysaccharide) that provides a liquid retention rate of 90% or more through cotton fiber filter paper in the presence of an acid catalyst (e.g., sulfuric acid) at 45 to 65°C for 2 to 5 hours, followed by addition of water and aging under heating (e.g., 55 to 75°C) for several hours (e.g., 1 to 3 hours).

[0095] After the reaction is complete, a poor solvent such as a water / methanol mixed solvent is added to thoroughly precipitate the product dissolved in the liquid phase, and the product can be recovered by solid-liquid separation, followed by washing and drying.

[0096] Alternatively, the acylation may be carried out in a homogeneous solution in which the polysaccharide and the acylating agent are dissolved in a solvent. The polysaccharide is preferably subjected to an activation treatment. The activation treatment can be carried out by a conventional method.

[0097] As the solvent for acylation, a solvent having high affinity with polysaccharides, such as N,N-dimethylacetamide, pyridine, or N-methylpyrrolidinone, is used.

[0098] As the acylating agent, a mixed acid anhydride having a long chain component and a short chain component can be formed in the same solvent as that used for acylation and used.

[0099] After the reaction is complete, a poor solvent such as methanol is added to precipitate the product, which can then be recovered by solid-liquid separation, followed by washing and drying.

[0100] <Component (B): Metal Hydroxide> The polysaccharide-based resin composition of the present disclosure contains a metal hydroxide as component (B). By including a metal hydroxide, the resin composition can have improved flame retardancy.

[0101] Examples of metal hydroxides include aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and hydrates thereof. Among these, aluminum hydroxide is particularly preferred because it has a high endothermic effect and excellent flame retardancy. The surface of the metal hydroxide may be surface-treated with various organic substances such as epoxy resins and phenolic resins. One type of metal hydroxide may be used alone, or two or more types may be used in combination. In one embodiment, the content of aluminum hydroxide in the total amount of component (B) is preferably 80% by mass or more, more preferably 90% by mass or more, and may even be 100% by mass.

[0102] 50% particle diameter of metal hydroxide (median diameter, D ５０ ) is not particularly limited, but is preferably 0.5 μm or more and 20 μm or less, more preferably 1 μm or more and 10 μm or less, and even more preferably 2 μm or more and 4 μm or less. When the 50% particle size of the metal hydroxide is within this range, it has excellent dispersibility in the resin composition, leading to improved flame retardancy and mechanical properties. If the 50% particle size of the metal hydroxide is too small, the viscosity of the resin composition may increase, resulting in reduced moldability. Furthermore, the increased viscosity may increase shear force during kneading or molding, resulting in deterioration of other components. On the other hand, if the 50% particle size of the metal hydroxide is too large, unevenness may occur on the surface of the resin composition, reducing the design properties. The average particle size of the metal hydroxide can be determined, for example, by measuring the volume-based median diameter using a diffraction / scattering method.

[0103] <Component (C): Phosphate Ester> The polysaccharide-based resin composition of the present disclosure contains a phosphate ester. Component (C) functions as a flame retardant and a plasticizer, and can impart flame retardancy and moldability to the resin composition.

[0104] Examples of phosphate esters include aliphatic phosphate esters, aromatic phosphate esters, aliphatic-aromatic phosphate esters, and aromatic condensed phosphate esters, with aromatic phosphate esters, such as aromatic phosphate esters and aromatic condensed phosphate esters, being preferred. Examples of phosphate esters include phosphate ester compounds obtained by reacting phosphoric acid with an aliphatic or aromatic alcohol, and aromatic condensed phosphate ester compounds, such as the reaction product of phosphorus oxychloride, a dihydric phenolic compound, and phenol (or alkylphenol). One type of phosphate ester may be used alone, or two or more types may be used in combination.

[0105] Examples of the aliphatic phosphate ester include tri-C phosphates such as trimethyl phosphate, triethyl phosphate, tripropyl phosphate, triisopropyl phosphate, tributyl phosphate, triisobutyl phosphate, and pentaerythritol phosphate. １－１０ Alkyl ester; phosphate di-C corresponding to the phosphate triester １－１０ Alkyl ester and mono-C phosphate １－１０ Alkyl esters and the like.

[0106] Examples of aromatic phosphate esters include tri-C phosphates such as triphenyl phosphate, tricresyl phosphate, trixylyl phosphate, diphenylcresyl phosphate, tri(isopropylphenyl) phosphate, diphenylethylcresyl phosphate, and cresyl di-2,6-xylenyl phosphate. ６－２０ aryl esters, etc. In one embodiment, it is preferably at least one selected from the group consisting of triphenyl phosphate and cresyl di-2,6-xylenyl phosphate.

[0107] Examples of the aliphatic-aromatic phosphate ester include methyl diphenyl phosphate and phenyl diethyl phosphate.

[0108] The condensed phosphate ester compound may, for example, be an aromatic condensed phosphate ester compound represented by the following chemical formula (I).

[0109]

[0110] In the above formula (I), R １ ~R ５ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; R １ ~R ５ may be the same or different. １ may be the same or different. ２ , R ３ , R ４ and R ５ The same applies to n. n is an integer of 1 to 30, preferably an integer of 1 to 10, more preferably an integer of 1 to 5, and even more preferably an integer of 1 to 3.

[0111] In formula (I), examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an amyl group, a tert-amyl group, a hexyl group, a 2-ethylhexyl group, an n-octyl group, a nonyl group, and a decyl group.

[0112] In formula (I), examples of the cycloalkyl group include a cyclohexyl group, etc. Examples of the aryl group include a phenyl group, a cresyl group, a xylyl group, a 2,6-xylyl group, a 2,4,6-trimethylphenyl group, a butylphenyl group, and a nonylphenyl group.

[0113] In formula (I), examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

[0114] As described above, the aromatic condensed phosphate ester compound is preferably a reaction product of phosphorus oxychloride, a dihydric phenolic compound, and phenol (or an alkylphenol), and the aromatic condensed phosphate ester compound represented by formula (I) is a compound in which the dihydric phenolic compound is a resorcinol (hereinafter also referred to as a "resorcinol compound") which may have a substituent. The aromatic condensed phosphate ester compound may also be a compound obtained by using 4,4'-biphenol or bisphenol A (each of which may have a substituent) in place of the resorcinol compound. Specifically, the aromatic condensed phosphate ester compound may have a 4,4'-biphenol residue or a bisphenol A residue, each of which may have a substituent, in place of the resorcinol compound residue in formula (I).

[0115] Examples of aromatic condensed phosphate ester compounds include resorcinol bis-dixylenyl phosphate, resorcinol bis-diphenyl phosphate, bisphenol A bis-diphenyl phosphate (BADP), bisphenol A bis-dicresyl phosphate, biphenol A bis-diphenyl phosphate, and biphenol A bis-dixylenyl phosphate.

[0116] Commercially available phosphate ester compounds may be used. Examples of commercially available phosphate ester compounds include TPP (triphenyl phosphate), TCP (tricresyl phosphate), TXP (tricresyl phosphate), CDP (cresyl diphenyl phosphate), PX-110 (cresyl di-2,6-xylenyl phosphate), PX-200 (resorcinol bis-dixylenyl phosphate), CR-733S (resorcinol bis-diphenyl phosphate), and CR-741 (bisphenol A bis(diphenyl phosphate)), all manufactured by Daihachi Chemical Industry Co., Ltd.

[0117] In one embodiment, particularly preferred phosphate esters include triphenyl phosphate (also referred to as "TPP"), cresyl di-2,6-xylenyl phosphate, and [(CH ３ ) ２ C ６ H３ O] ２ P(O)OC ６ H ４ OP (O) [OC ６ H ３ (CH ３ ) ２ ] ２ It is preferable to use at least one selected from the group consisting of aromatic condensed phosphate esters represented by the following formula:

[0118] In one embodiment, triphenyl phosphate (TPP) is preferably included as component (C). TPP is less volatile and has high compatibility with component (A). Furthermore, the use of TPP allows the formation of a resin composition with high mechanical strength. Furthermore, the use of TPP increases the thermoplasticity of the resin, allowing the addition of large amounts of inorganic substances such as metal hydroxides and glass fibers, resulting in high flame retardancy.

[0119] In one embodiment, component (C) is cresyl di-2,6-xylenyl phosphate or [(CH ３ ) ２ C ６ H ３ O] ２ P(O)OC ６ H ４ OP (O) [OC ６ H ３ (CH ３ ) ２ ] ２ When the aromatic condensed phosphate ester represented by the formula (I) is contained, a molded article having particularly excellent mechanical strength (bending strength, etc.) and heat resistance can be formed.

[0120] <Component (D): Glass Fiber> The polysaccharide-based resin composition of the present disclosure contains glass fiber as component (D). The inclusion of glass fiber in the resin composition improves strength, heat resistance, and flexural strength, as well as flame retardancy. The glass fiber is not particularly limited, but the fiber length of the glass fiber before melt-kneading is, for example, preferably 0.5 mm or more, and preferably 30 mm or less, more preferably 10 mm or less. The cross-sectional shape of the glass fiber is not particularly limited, and examples include circular, elliptical, oblong, and non-circular. The fiber diameter of the glass fiber, calculated as the cross-sectional area of ​​a perfect circle, may be, for example, 3 to 20 μm. The surface of the glass fiber may be treated with a surface treatment agent. It may be preferable for the surface treatment agent to contain, as its main agent, at least one resin selected from polyolefin resins and resins having an epoxy functional group, in terms of excellent bleed resistance.

[0121] <Component (E): Anti-Drip Agent> The polysaccharide-based resin composition of the present disclosure contains an anti-drip agent as component (E). By including component (E), the polysaccharide-based resin composition shrinks when heated, preventing the molten resin from dripping (drip) and spreading the combustion. As the anti-drip agent, a fluorine-based anti-drip agent (preferably a fluoropolymer) is preferred, and it is more preferred to include a fluoropolymer that forms a fibrous structure (fibril structure) in the resin composition. By incorporating a fluoropolymer, the effect of suppressing the drip phenomenon during combustion can be enhanced.

[0122] Examples of anti-drip agents include fluorine-based resins such as polytetrafluoroethylene (PTFE), tetrafluoroethylene copolymers (e.g., tetrafluoroethylene / hexafluoropropylene copolymers), acrylic-modified polytetrafluoroethylene, polyvinylidene fluoride, and polyhexafluoropropylene; and alkali metal salt compounds of perfluoroalkanesulfonic acid, such as sodium perfluoromethanesulfonate, potassium perfluoro-n-butanesulfonate, potassium perfluoro-t-butanesulfonate, sodium perfluorooctanesulfonate, and calcium perfluoro-2-ethylhexanesulfonate, or alkaline earth metal salts of perfluoroalkanesulfonic acid. Furthermore, various forms of fluoropolymers can also be used as the fluorine-containing polymer, such as fine powder fluoropolymers, aqueous dispersions of fluoropolymers, mixtures of powdered fluoropolymers and acrylonitrile-styrene copolymers, and mixtures of powdered fluoropolymers and polymethyl methacrylate. Similarly, other anti-drip agents, such as silicone compounds such as silicone rubbers, and layered silicates such as talc, may also be blended. These may be used alone or in combination of two or more.

[0123] Among these, fluorine-based anti-drip agents having fibril-forming ability are preferred, and polytetrafluoroethylene (PTFE) is particularly preferred. The molecular weight of the fluorine-based anti-drip agent (particularly PTFE) is not limited, but the number average molecular weight calculated from the standard specific gravity is preferably 1,000,000 to 10,000,000, more preferably 2,000,000 to 9,000,000. PTFE may be in the form of a solid or an aqueous dispersion.

[0124] <Amounts> Preferred embodiments of the amounts of each component contained in the polysaccharide resin composition of the present disclosure are described below.

[0125] The content of the polysaccharide resin of component (A) is preferably 20% by mass or more, more preferably 25% by mass or more, even more preferably 30% by mass or more, relative to 100% by mass of the total content of components (A), (B), (C), (D) and (E) (also referred to as "components (A) to (E)"), and is preferably 50% by mass or less, more preferably 45% by mass or less, even more preferably 40% by mass or less.

[0126] The content of the metal hydroxide of component (B) is preferably 35% by mass or more, more preferably 37% by mass or more, and even more preferably 40% by mass or more, relative to 100% by mass of the total content of components (A), (B), (C), (D), and (E), and is preferably 50% by mass or less, more preferably 47% by mass or less, and even more preferably 45% by mass or less. If the content of component (B) is too high, the impact strength, bending strain at break, and thermoplasticity may be reduced. If the content of component (B) is too low, the flame retardancy may be reduced.

[0127] The content of the phosphate ester of component (C) is preferably 1.9% by mass or more, more preferably 2.0% by mass or more, even more preferably 2.5% by mass or more, and even more preferably 3.0% by mass or more, relative to the total content of components (A), (B), (C), (D), and (E) (100% by mass), and is preferably 10% by mass or less, more preferably 9% by mass or less, even more preferably 8% by mass or less, and may even be 7% by mass or less. If the content of component (C) is too high, the plasticizing effect will be greater, which may result in reduced mechanical strength (such as bending properties), reduced heat resistance, or bleeding out. If the content of component (C) is too low, the thermoplasticity or flame retardancy may be insufficient.

[0128] The content of the glass fiber of component (D) is preferably 8% by mass or more, more preferably 10% by mass or more, and may be 12% by mass or more, relative to 100% by mass of the total content of components (A), (B), (C), (D), and (E). It is also preferably 27% by mass or less, more preferably 25% by mass or less, and may be 22% by mass or less. If the content of component (D) is too high, impact strength, bending strain at break, and thermoplasticity may decrease. If the content of component (D) is too low, flame retardancy may be insufficient.

[0129] The content of the anti-drip agent of component (E) is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.3% by mass or more, and is preferably 2% by mass or less, more preferably 1.5% by mass or less, even more preferably 0.8% by mass or less, relative to the total content of components (A), (B), (C), (D), and (E) (100% by mass). If the content of component (E) is too high, the thermoplasticity of the resin composition may decrease, making processing difficult. If the content of component (E) is too low, the flame retardancy may be insufficient.

[0130] The inventors of the presently disclosed invention have found that when the contents of component (A), component (B), component (C), and component (D) are within the above ranges, a polysaccharide-based resin composition can be obtained that is particularly excellent in all of flame retardancy, mechanical properties, heat resistance, and thermoplasticity.

[0131] The total content of components (A) to (E) relative to the total mass of the polysaccharide resin composition (100% by mass) is not limited, but is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and still more preferably 95% by mass or more, or may be 100% by mass.

[0132] The MFR (melt flow rate at 210°C and a load of 5 kg) of the polysaccharide resin composition according to the present disclosure is not limited, but is preferably 0.1 g / 10 min or more in order to prevent excessively low fluidity that would interfere with molding. The upper limit of the MFR is not limited, but is preferably, for example, 100 g / 10 min or less. If the MFR is too high, the appearance of the molded article may be deteriorated. The MFR can be measured by the measurement method described in the Examples.

[0133] The Charpy impact strength measured by the method described in the examples using the polysaccharide-based resin composition according to the present disclosure is not limited, but is preferably 1.5 kJ / m ２ More preferably, 2 kJ / m ２ The Charpy impact strength can be measured by the method described in the examples.

[0134] When a molded article is produced using the polysaccharide resin according to the present disclosure by the method described in the Examples, the flexural strength of the obtained molded article is not limited, but is preferably 30 MPa or more, more preferably 40 MPa or more, and the flexural modulus is preferably 1.0 GPa or more, more preferably 1.5 GPa or more, and even more preferably 2 GPa or more. Furthermore, the flexural strain at break of the molded article is preferably 1.0% or more, more preferably 1.2% or more, and preferably 5% or less, more preferably 4% or less. These mechanical properties can be measured by the methods described in the Examples.

[0135] The deflection temperature under load (HDT) measured by the method described in the examples using the polysaccharide-based resin according to the present disclosure is preferably 70°C or higher.

[0136] The polysaccharide resin composition may contain other components to the extent that the desired properties are not impaired.

[0137] The polysaccharide resin composition may contain, in addition to the components (A) to (E), for example, a colorant.

[0138] (Colorant) In one embodiment, the polysaccharide-based resin composition may contain a colorant such as a black colorant.

[0139] As the black colorant, carbon black is preferred.

[0140] The average particle size of this carbon black is not limited, but is preferably 1 to 20 nm, more preferably 5 to 20 nm, and even more preferably 8 to 18 nm. The smaller the average particle size, the lower the brightness of the molded article, and the more likely it is to have a high-quality black (jet black) appearance. Conversely, the larger the average particle size, the higher the dispersibility. From these perspectives, it is preferable to use carbon black with a particle size within the above range.

[0141] This average particle size is the arithmetic mean particle size of carbon black particles determined by observing the particles under an electron microscope.

[0142] As colorants other than the black colorant, organic or inorganic pigments or dyes can be used.

[0143] The resin composition may contain, as other components, additives commonly used in ordinary molding resin materials, provided that the purpose of the present disclosure is not impaired. Examples of such additives include phenolic or phosphorus-based antioxidants, light stabilizers, UV absorbers, antistatic agents, antibacterial and antifungal agents, fillers, etc. In particular, the resin composition may contain additives commonly used in ordinary cellulose-based resins.

[0144] The resin composition of the present disclosure may contain an inorganic or organic granular or fibrous filler, as long as the object of the present disclosure is not impaired. By adding a filler, strength and rigidity can be further improved. Examples of fillers include mineral particles (talc, mica, calcined silica earth, kaolin, sericite, bentonite, smectite, clay, silica, quartz powder, glass beads, glass powder, glass flakes, milled fiber, wollastonite (or wollastonite), etc.), boron-containing compounds (boron nitride, boron carbide, titanium boride, etc.), metal carbonates (magnesium carbonate, heavy calcium carbonate, light calcium carbonate, etc.), metal silicates (calcium silicate, aluminum silicate, magnesium silicate, magnesium aluminosilicate, etc.), metal oxides (magnesium oxide, etc.), metal sulfates (calcium sulfate, barium sulfate, etc.), metal carbides (silicon carbide, aluminum carbide, titanium carbide, etc.), metal nitrides (aluminum nitride, silicon nitride, titanium nitride, etc.), white carbon, and various metal foils. Examples of fibrous fillers include organic fibers (natural fibers, paper, etc.), inorganic fibers (asbestos fibers, carbon fibers, silica fibers, silica-alumina fibers, wollastonite, zirconia fibers, potassium titanate fibers, etc.), metal fibers, etc. These fillers can be used alone or in combination.

[0145] <Method for Producing Polysaccharide-Based Resin Composition> The method for producing the polysaccharide-based resin composition is not particularly limited. For example, the polysaccharide-based resin composition can be obtained by melt-mixing component (A), component (B), component (C), component (D), and component (E), and, if necessary, other components, using a conventional mixer. The order of mixing is arbitrary. As the mixer, for example, a compounding device such as a tumbler mixer, ribbon blender, single-screw or multi-screw mixer extruder, kneading kneader, or kneading roll can be used. After melt-mixing, the mixture can be granulated into an appropriate shape if necessary, and can be pelletized using, for example, a pelletizer.

[0146] <Molded Article> The polysaccharide-based resin composition according to the present disclosure can be used as a base resin for a molding material (resin composition) and can be molded into a desired shape by a conventional molding method, without any particular limitations on the shape. Here, the term "base resin" refers to the main component of the molding material, and means that other components may be contained within a range that does not interfere with the function of the main component. The content of the main component is not particularly specified, but includes cases in which the main component accounts for 50% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more of the composition. The polysaccharide-based resin composition can be molded into a molded article according to the intended use by a conventional molding method such as injection molding, injection compression molding, extrusion molding, or hot press molding.

[0147] Molded articles formed using the polysaccharide-based resin composition according to the present disclosure have excellent flame retardancy, mechanical properties, and heat resistance, and can therefore be applied to housings, exteriors, decorative panels, and decorative sheets, and can be used in place of components used in, for example, electronic devices, home appliances, building materials, furniture, and automobiles. For example, they can also be used in housings and exterior parts of electronic devices and home appliances, interior building materials, and automobile interior materials.

[0148] Products such as electronic devices, home appliances, automobiles, building materials, and furniture can be provided that include molded articles formed using the resin compositions according to the present disclosure.

[0149] Applications for electronic devices and home appliances include housings for personal computers, landline phones, mobile phone terminals, smartphones, tablets, POS terminals, routers, projectors, speakers, lighting equipment, copiers, multifunction printers, calculators, remote controls, refrigerators, washing machines, humidifiers, dehumidifiers, video recorder players, vacuum cleaners, air conditioners, rice cookers, electric shavers, electric toothbrushes, dishwashers, broadcasting equipment, clock faces and exteriors, and cases for mobile devices such as smartphones.

[0150] Automotive applications include interior instrument panels, dashboards, cup holders, door trim, armrests, door handles, door locks, steering wheels, brake levers, ventilators, and shift levers.

[0151] The polysaccharide resin composition of the present disclosure will be described in more detail below using specific examples, but the invention of the present disclosure is not limited to these.

[0152] The components used in the examples and comparative examples are as follows.

[0153] <Preparation of Component (A)> The degree of polymerization of cellulose and the weight average molecular weight of paramylon used in preparing component (A) were determined by the following measurements.

[0154] (Degree of polymerization of cellulose) The degree of polymerization of cellulose (before the introduction of long-chain components and short-chain components) was determined by measuring the intrinsic viscosity number [η] in accordance with JIS P8215 and calculating it according to the following formula: [η] = 1.67 × DP where "DP" represents the degree of polymerization. ０．７１

[0155] (GPC measurement conditions for paramylon) The weight-average molecular weight of paramylon was measured under the following conditions. Column: PLgel 20 μm MIXED-A (product name, manufactured by Agilent Technologies, Inc.) Eluent: dimethylacetamide (DMAc) solution (0.1 M LiCl) Flow rate: 0.5 mL / min Detector: RI (differential refractive index) (RI-71 type 201 (16X) manufactured by Tosoh Corporation) Temperature: 23.0° C. Standard sample: Pullulan standard

[0156] (Synthesis Example 1) [Synthesis of Cellulose Propionate Stearate (Cellulose Derivative A)] (1) 100 g of cellulose (degree of polymerization 560) was added to a mixed solvent of 1.32 L of N-methylpyrrolidone and 183 mL of pyridine and dispersed. The mixture was stirred overnight at room temperature under a nitrogen atmosphere to obtain a dispersion. (2) After the dispersion obtained in (1) was cooled to -4°C, 74.8 g of premixed stearoyl chloride and 171 g of propionyl chloride were added to the dispersion in (1) while maintaining the temperature below 10°C. The mixture was heated to 90°C and then stirred for 4 hours while heating. (3) The reaction solution was then cooled to 65°C, and 752 mL of methanol was added dropwise and stirred for approximately 30 minutes. An additional 833 mL of water was added to precipitate the product. The product was collected by suction filtration, washed five times with 1.30 L of methanol, and then vacuum dried at 105°C for 5 hours to obtain a cellulose-based resin (yield: 209 g (94%)). The resulting cellulose propionate stearate (cellulose derivative A) had a DSSt (degree of substitution with long-chain components) of 0.27 and a DSPr (degree of substitution with short-chain components) of 2.4 ( １ (Calculated from H-NMR measurement results).

[0157] (Synthesis Example 2) [Synthesis of Cellulose Propionate Laurate (Cellulose Derivative B)] (1) 100 g of cellulose (degree of polymerization 560) was added to a mixed solvent of 1.32 L of N-methylpyrrolidone and 183 mL of pyridine, and the mixture was stirred overnight at room temperature under a nitrogen atmosphere to obtain a dispersion. (2) After the dispersion obtained in (1) was cooled to -4 ° C, 54.2 g of premixed lauroyl chloride and 171 g of propionyl chloride were added to the dispersion in (1) while maintaining the temperature below 10 ° C, and the mixture was heated to 90 ° C and then stirred for 4 hours while heating. (3) Thereafter, the reaction solution was cooled to 65 ° C, 750 mL of methanol was added dropwise, and the mixture was stirred for about 30 minutes. After neutralizing with 217 g of triethylamine, 833 mL of water was added to precipitate the product. The product was collected by suction filtration, washed five times with 1.10 L of a methanol / water mixture (10 / 1 v / v), and then vacuum dried at 105° C. for 5 hours to obtain a cellulose-based resin (yield: 196 g (89%)). The resulting cellulose propionate aurate (cellulose derivative B) had a DSLa (degree of substitution with long-chain components) of 0.28 and a DSPr (degree of substitution with short-chain components) of 2.5.

[0158] Synthesis Example 3 [Synthesis of Paramylon Propionate Stearate (Paramylon Derivative C)] (1) 500 g of paramylon and 5.0 kg of a 5% aqueous hydrochloric acid solution were added to a reactor and stirred at 90°C for 4 hours. The reaction solution was then returned to room temperature. The product was collected by suction filtration, washed five times with 5.0 kg of water, and the washed solid was vacuum-dried at 105°C for 5 hours to obtain Paramylon 1 (yield: 373 g (75% yield)). The weight-average molecular weight (Mw) of Paramylon 1 was 121,000. (2) 100 g of Paramylon 1 was dispersed in a mixed solvent of 1.14 L of N-methylpyrrolidone and 158 mL of pyridine, and the mixture was stirred overnight at room temperature under a nitrogen atmosphere. (3) After cooling the dispersion obtained in (2) to -4 ° C, 37.5 g of premixed stearoyl chloride and 137 g of propionyl chloride were added to the dispersion in (2) while maintaining the temperature below 10 ° C., and the mixture was heated to 90 ° C. and stirred for 4 hours. (4) The reaction solution was then cooled to 65 ° C., and 1.30 L of methanol was added dropwise and stirred for about 30 minutes. 286 mL of water was added to precipitate the product. The product was recovered by suction filtration, washed five times with 1.19 L of a methanol / water mixture (10 / 1 v / v), and vacuum dried at 105 ° C. for 5 hours to obtain paramylon propionate stearate (yield: 170 g (84%)). The resulting paramylon propionate stearate (paramylon derivative C) had a DSSt (degree of substitution with long-chain components) of 0.19 and a DSPr (degree of substitution with short-chain components) of 2.1.

[0159] <Component (B)> (b1) Aluminum hydroxide (BE043STE, manufactured by Nippon Light Metal Co., Ltd., (average particle size: 4 μm)

[0160] <Component (C)> (c1) TPP: triphenyl phosphate (manufactured by Daihachi Chemical Industry Co., Ltd.) (c2) PX-110: cresyl di-2,6-xylenyl phosphate (manufactured by Daihachi Chemical Industry Co., Ltd.) (c3) PX-200: aromatic condensed phosphate ester [(CH ３ ) ２ C ６ H ３ O] ２ P(O)OC ６ H ４ OP (O) [OC ６ H ３ (CH３ ) ２ ] ２ (Manufactured by Daihachi Chemical Industry Co., Ltd.)

[0161] <Component (D)> (d1) Glass fiber (GF) (manufactured by Nitto Boseki, product name: Chopped Strand CSX3J451)

[0162] <Component (E)> (e1) Polytetrafluoroethylene (PTFE) (manufactured by Daikin Industries, Ltd., product name: Polyflon MPA FA-500H)

[0163] [Mixing and molding of derivatives A to C with additives] The resins obtained in Synthesis Examples 1 to 3 were mixed with additives as follows. The blending ratios of each component are shown in Tables 2 to 4.

[0164] Example 1 63.1 g of cellulose derivative A, 60.0 g of aluminum hydroxide (BE043STE), 11.1 g of phosphoric acid ester (TPP), 15.0 g of glass fiber (CSX3J451), and 0.75 g of PTFE were placed in a bag and mixed in advance, and then mixed at 210° C. using a twin-screw kneader (a small kneader, the same applies to all of the following Examples and Comparative Examples) to prepare pellets. The obtained pellets were molded using an injection molding machine, and the physical properties and flame retardancy (3.1 mmt) were evaluated.

[0165] Example 2 56.7 g of cellulose derivative A, 60.0 g of aluminum hydroxide (BE043STE), 10.0 g of phosphoric acid ester (TPP), 22.5 g of glass fiber (CSX3J451), and 0.75 g of PTFE were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 210° C. to prepare pellets. The obtained pellets were molded using an injection molding machine, and the physical properties and flame retardancy (3.1 mmt) were evaluated.

[0166] Example 3 67.2 g of cellulose derivative A, 80.0 g of aluminum hydroxide (BE043STE), 11.9 g of phosphoric acid ester (TPP), 40.0 g of glass fiber (CSX3J451), and 1.00 g of PTFE were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 210° C. to prepare pellets. The obtained pellets were molded using a molding machine, and the physical properties and flame retardancy (3.1 mmt) were evaluated.

[0167] Example 4 58.7 g of cellulose derivative A, 80.0 g of aluminum hydroxide (BE043STE), 10.4 g of phosphoric acid ester (TPP), 50.0 g of glass fiber (CSX3J451), and 1.00 g of PTFE were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 210° C. to prepare pellets. The obtained pellets were molded using a molding machine, and the physical properties and flame retardancy (3.1 mmt) were evaluated.

[0168] Example 5 71.1 g of cellulose derivative A, 80.0 g of aluminum hydroxide (BE043STE), 7.90 g of phosphoric acid ester (TPP), 40.0 g of glass fiber (CSX3J451), and 1.00 g of PTFE were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 210° C. to prepare pellets. The obtained pellets were molded using a molding machine, and the physical properties and flame retardancy (3.1 mmt) were evaluated.

[0169] Example 6 75.1 g of cellulose derivative A, 80.0 g of aluminum hydroxide (BE043STE), 3.95 g of phosphoric acid ester (TPP), 40.0 g of glass fiber (CSX3J451), and 1.00 g of PTFE were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 210° C. to prepare pellets. The obtained pellets were molded using a molding machine, and the physical properties and flame retardancy (3.1 mmt) were evaluated.

[0170] Example 7 68.1 g of cellulose derivative B, 75.0 g of aluminum hydroxide (BE043STE), 12.1 g of phosphoric acid ester (TPP), 27.1 g of glass fiber (CSX3J451), and 0.90 g of PTFE were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 220° C. to prepare pellets. The obtained pellets were molded using a molding machine, and the physical properties and flame retardancy (3.1 mmt) were evaluated.

[0171] Example 8 68.2 g of cellulose derivative B, 72.0 g of aluminum hydroxide (BE043STE), 12.3 g of phosphate ester (PX110), 27.0 g of glass fiber (CSX3J451), and 0.90 g of PTFE were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 220° C. to prepare pellets. The obtained pellets were molded using a molding machine, and the physical properties and flame retardancy (3.1 mmt) were evaluated.

[0172] Example 9 68.1 g of cellulose derivative B, 72.0 g of aluminum hydroxide (BE043STE), 12.1 g of phosphate ester (PX200), 27.0 g of glass fiber (CSX3J451), and 0.90 g of PTFE were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 220° C. to prepare pellets. The obtained pellets were molded using a molding machine, and the physical properties and flame retardancy (3.1 mmt) were evaluated.

[0173] Example 10 34.2 g of paramylon derivative C, 44.0 g of aluminum hydroxide (BE043STE), 3.80 g of phosphate ester (TPP), 27.5 g of glass fiber (CSX3J451), and 0.55 g of PTFE were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 200° C. to produce pellets. The resulting pellets were molded using a molding machine, and the physical properties and flame retardancy (2.4 mmt) were evaluated.

[0174] Example 11 55.9 g of paramylon derivative C, 72.0 g of aluminum hydroxide (BE043STE), 6.21 g of phosphate ester (PX200), 45.0 g of glass fiber (CSX3J451), and 0.90 g of PTFE were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 230° C. to produce pellets. The resulting pellets were molded using a molding machine, and the physical properties and flame retardancy (2.4 mmt) were evaluated.

[0175] <Comparative Example 1> 76.0 g of cellulose derivative A, 60.0 g of aluminum hydroxide (BE043STE), 13.4 g of phosphoric acid ester (TPP), and 0.56 g of PTFE were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 210° C. to prepare pellets. The obtained pellets were molded using a molding machine, and the physical properties and flame retardancy (3.1 mmt) were evaluated.

[0176] Comparative Example 2 65.6 g of cellulose derivative A, 80.0 g of aluminum hydroxide (BE043STE), 3.45 g of phosphoric acid ester (TPP), 50.0 g of glass fiber (CSX3J451), and 1.00 g of PTFE were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 210° C. to prepare pellets. The obtained pellets were molded using a molding machine, and the physical properties and flame retardancy (3.1 mmt) were evaluated.

[0177] Comparative Example 3 69.5 g of cellulose derivative A, 45.0 g of aluminum hydroxide (BE043STE), 12.3 g of phosphoric acid ester (TPP), 22.5 g of glass fiber (CSX3J451), and 0.75 g of PTFE were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 210° C. to prepare pellets. The obtained pellets were molded using a molding machine, and the physical properties and flame retardancy (3.1 mmt) were evaluated.

[0178] Comparative Example 4 36.1 g of paramylon derivative C, 44.0 g of aluminum hydroxide (BE043STE), 1.90 g of phosphate ester (TPP), 27.5 g of glass fiber (CSX3J451), and 0.55 g of PTFE were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 200° C. to produce pellets. The resulting pellets were molded using a molding machine, and the physical properties and flame retardancy (2.4 mmt) were evaluated.

[0179] Comparative Example 5 34.5 g of paramylon derivative C, 40.0 g of aluminum hydroxide (BE043STE), 25.0 g of glass fiber (CSX3J451), and 0.50 g of PTFE were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 200° C. to produce pellets. The resulting pellets were molded using a molding machine, and the physical properties and flame retardancy (2.4 mmt) were evaluated.

[0180] [Preparation of Molded Article] The molding machines used in the above Examples and Comparative Examples are as follows: Molding was carried out by setting the molding machine cylinder temperature to 190 to 230°C, the mold temperature to 65°C, and the dwell pressure to 60 to 100 MPa.

[0181] In molding using a cellulose derivative, a molding machine, HAAKE MiniJet II manufactured by Thermo Electron Corporation, was used.

[0182] In molding using the paramylon derivative, a molding machine, HAAKE MiniJet II manufactured by Thermo Electron Corporation, was used.

[0183] [Measurement of Charpy Impact Strength] A Charpy impact test was carried out in accordance with JIS K7111-1 (notched: Type A (notch cutter tip R 0.25 mm)) using an evaluation sample having the shape of JIS K 7162 test piece 1A. The evaluation sample (molded body) had a length of 80 mm, a width of 10 mm, and a thickness of 4.0 mm.

[0184] [Measurement of flexural strength, flexural modulus, and flexural strain at break] A flexural test was carried out to measure the flexural strength, flexural modulus, and flexural strain at break in accordance with JIS K 7171. The molded body used in the test had a length of 80 mm, a width of 10 mm, and a thickness of 4.0 mm.

[0185] [Measurement of Deflection Temperature Under Load (HDT)] In accordance with JIS K7191-2, the oil temperature was raised at a constant rate (120°C / h), and a bending stress of 0.45 MPa was applied to an evaluation sample having a length of 80 mm, a width of 10 mm, and a thickness of 4.0 mm. The temperature at which the specified deflection amount was reached was taken as the deflection temperature under load (HDT) (support distance: 64 mm). The measured HDT was used as an index of heat resistance.

[0186] [Measurement of fluidity (melt flow rate (MFR))] Using a Takashita flow tester (manufactured by Shimadzu Corporation, product name: CFT-500D), MFR was measured in accordance with JIS 7210:1990 under the conditions of a temperature of 210°C, a load of 5 kg, a die of 2 mmφ×10 mm (hole diameter 2 mm, hole length 10 mm), and a preheat time of 2 minutes (the time from the time the sample was filled into the cylinder and the piston was inserted until the load was applied).

[0187] [Evaluation of Flame Retardancy] Flame retardancy was evaluated in accordance with UL94V using molded articles (test pieces) of the following shapes: Molded article using a cellulose derivative: thickness 3.1 mm, width 13 mm, length 127 mm Molded article using a paramylon derivative: thickness 2.4 mm, width 12.4 mm, length 80 mm

[0188] (Flammability Test (UL94V Test)) The flammability test was conducted in accordance with the UL94 test (flammability test for plastic materials for equipment parts) established by Underwriters Laboratories, after leaving a molded article (test piece) for the flammability test obtained by injection molding in a thermostatic chamber at a temperature of 23°C and a humidity of 50% for 48 hours. UL94V is a method for evaluating flame retardancy based on the burning time and dripping properties after a burner flame (20±1 mm flame) is applied to the bottom end of a test piece of a predetermined size held vertically for 10 seconds, and the test pieces are classified into the classes shown in Table 1 below.

[0189]

[0190] Flame retardancy is ranked from best to worst as V-0, V-1, and V-2. However, materials that do not fall into any of the V-0 to V-2 ranks (poor flame retardancy) are rated as V- Not Compliant.

[0191] The flaming combustion time is the length of time the test specimen continues to burn with a flame after the ignition source (burner) is removed, where t1 is the burning time after the first flame contact, t2 is the burning time after the second flame contact, and t3 is the afterglow (flameless combustion) time after the second flame contact. The second flame contact is performed by immediately applying the burner flame to the test specimen for 10 seconds after the flame has gone out after the first flame contact. The ignition of cotton by dripping is determined by whether or not the cotton marker located 300±10 mm below the bottom end of the test specimen is ignited by dripping from the test specimen.

[0192] The compositions of the resin compositions of the examples and comparative examples and the results of various evaluations are shown in Tables 2 to 4. In the tables, the numerical values ​​relating to the compositions are in "mass %."

[0193]

[0194]

[0195]

[0196] The composites of cellulose derivatives or paramylon derivatives shown in Examples 1 to 11 all possessed high bending properties (bending strength > 40 MPa, bending stress (bending modulus) > 1.0 GPa), high heat resistance (> 70°C), flame retardancy (UL: V-2 or higher), and excellent heat flowability (MFR: > 0.1 g / 10 min, 210°C, 5 kgf). Furthermore, when PX110 or PX200 was used instead of TPP as the phosphate ester, further increases in bending strength were observed (Table 3). Furthermore, all of the molded articles in Examples 1 to 11 were shown to have good Charpy impact strength.

[0197] In contrast, Comparative Example 1 had poor bending properties and flame retardancy because no GF was added. Comparative Example 2 had poor fluidity when heated because the amount of phosphate ester added was low. Comparative Example 3 had poor flame retardancy because the amount of aluminum hydroxide added was low. Comparative Example 4 had poor fluidity when heated because the amount of phosphate ester added was low, and Comparative Example 5, which did not add phosphate ester, also had poor flame retardancy. Comparative Examples 2, 4, and 5 had poor fluidity when heated because the content of phosphate ester was low, making it impossible to measure MFR.

[0198] Although the present invention has been described above with reference to embodiments and examples, the present invention is not limited to the above-described embodiments and examples. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

[0199] A part or all of the above disclosure may be described as in the following appendices, but the disclosure of the present application is not limited to the following appendices.

[0200] (Supplementary Note 1) Component (A): (A1) at least one polysaccharide-based resin selected from the group consisting of cellulose-based resins in which at least a portion of the hydrogen atoms of hydroxy groups of cellulose are substituted with a long-chain component which is a linear saturated aliphatic acyl group having 12 or more carbon atoms and a short-chain component which is an acyl group having 2 or 3 carbon atoms, and (A2) paramylon-based resins in which at least a portion of the hydrogen atoms of hydroxy groups of paramylon are substituted with a long-chain component which is a linear saturated aliphatic acyl group having 12 or more carbon atoms and a short-chain component which is an acyl group having 2 or 3 carbon atoms; component (B): a metal hydroxide; component (C): a phosphate ester; component (D): glass fiber; and component (E): an anti-drip agent, wherein, relative to the total content of components (A) to (E) of 100% by mass, the content of component (A) is 20% by mass to 50% by mass, and the content of component (B) is 35% by mass to 50% by mass, A polysaccharide-based resin composition, comprising: a component (C) content of 1.9% by mass to 10% by mass; and a component (D) content of 8% by mass to 27% by mass.

[0201] (Appendix 2) The polysaccharide resin composition according to Appendix 1, wherein the content of component (E) is 0.1% by mass to 2% by mass, relative to 100% by mass of the total content of components (A) to (E).

[0202] (Appendix 3) The polysaccharide resin composition according to Appendix 1 or 2, wherein the component (B) contains aluminum hydroxide (preferably aluminum hydroxide).

[0203] (Appendix 4) The component (C) is triphenyl phosphate, cresyl di-2,6-xylenyl phosphate, and [(CH ３ ) ２ C ６ H ３ O] ２ P(O)OC ６ H ４ OP (O) [OC ６ H ３ (CH ３ ) ２ ] ２ (preferably, triphenyl phosphate, cresyl di-2,6-xylenyl phosphate, and [(CH ３ )２ C ６ H ３ O] ２ P(O)OC ６ H ４ OP (O) [OC ６ H ３ (CH ３ ) ２ ] ２ The polysaccharide-based resin composition according to any one of Appendices 1 to 3, wherein the compound is one or more phosphoric acid esters selected from the group consisting of compounds represented by the following formula:

[0204] (Appendix 5) The polysaccharide resin composition according to any one of Appendices 1 to 4, wherein the component (E) is a fluorine-based anti-drip agent.

[0205] (Appendix 6) The polysaccharide-based resin composition according to Appendix 5, wherein the fluorine-based anti-drip agent contains polytetrafluoroethylene (preferably polytetrafluoroethylene).

[0206] (Appendix 7) The polysaccharide-based resin composition according to any one of Appendices 1 to 6, wherein component (A) is (A1) a cellulose-based resin in which at least some of the hydrogen atoms of hydroxy groups of cellulose have been substituted with long-chain components which are linear saturated aliphatic acyl groups having 12 or more carbon atoms and short-chain components which are acyl groups having 2 or 3 carbon atoms.

[0207] (Appendix 8) The polysaccharide-based resin composition according to any one of Appendices 1 to 6, wherein component (A) is a paramylon-based resin in which at least some of the hydrogen atoms of the hydroxy groups of (A2) paramylon have been substituted with long-chain components that are linear saturated aliphatic acyl groups having 12 or more carbon atoms and short-chain components that are acyl groups having 2 or 3 carbon atoms.

[0208] (Appendix 9) Component (C) is triphenyl phosphate, cresyl di-2,6-xylenyl phosphate, and [(CH ３ ) ２ C ６ H ３ O] ２ P(O)OC ６ H ４ OP (O) [OC ６ H ３ (CH ３ ) ２ ] ２The polysaccharide-based resin composition according to any one of appendices 3 to 8, wherein the polysaccharide-based resin composition is one or more phosphate esters selected from the group consisting of compounds represented by the formula:

[0209] (Appendix 10) The polysaccharide resin composition according to any one of Appendices 1 to 9, wherein the content of component (A) is 25 to 50 mass% relative to 100 mass% of the total content of components (A) to (E).

[0210] (Appendix 11) A molded article formed using the polysaccharide resin composition according to any one of Appendices 1 to 10.

[0211] This application claims priority based on Japanese Patent Application No. 2023-144465, filed September 6, 2023, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. Component (A): (A1) at least one polysaccharide-based resin selected from the group consisting of a cellulose-based resin in which at least a portion of the hydrogen atoms of hydroxyl groups of cellulose are substituted with a long-chain component which is a linear saturated aliphatic acyl group having 12 or more carbon atoms and a short-chain component which is an acyl group having 2 or 3 carbon atoms, and (A2) a paramylon-based resin in which at least a portion of the hydrogen atoms of hydroxyl groups of paramylon are substituted with a long-chain component which is a linear saturated aliphatic acyl group having 12 or more carbon atoms and a short-chain component which is an acyl group having 2 or 3 carbon atoms; component (B): a metal hydroxide; component (C): a phosphate ester; component (D): glass fiber; and component (E): a drip prevention agent; wherein, relative to the total content of components (A) to (E) of 100% by mass, the content of component (A) is 20% by mass to 50% by mass, and the content of component (B) is 35% by mass to 50% by mass, A polysaccharide-based resin composition, comprising: a component (C) content of 1.9% by mass to 10% by mass; and a component (D) content of 8% by mass to 27% by mass.

2. The polysaccharide resin composition according to claim 1, wherein the content of component (E) is 0.1% by mass to 2% by mass relative to 100% by mass of the total content of components (A) to (E).

3. The polysaccharide resin composition according to claim 1 or 2, wherein the component (B) contains aluminum hydroxide.

4. The component (C) is triphenyl phosphate, cresyl di-2,6-xylenyl phosphate, and [(CH ３ ) ２ C ６ H ３ O] ２ P(O)OC ６ H ４ OP (O) [OC ６ H ３ (CH ３ ) ２ ] ２ 3. The polysaccharide-based resin composition according to claim 1, further comprising one or more phosphoric acid esters selected from the group consisting of compounds represented by the following formula:

5. The polysaccharide resin composition according to claim 1 or 2, wherein the component (E) is a fluorine-based drip prevention agent.

6. The polysaccharide resin composition according to claim 5, wherein the fluorine-based anti-drip agent comprises polytetrafluoroethylene.

7. A polysaccharide resin composition according to claim 1 or 2, in which component (A) is a cellulose resin in which at least a portion of the hydrogen atoms of the hydroxyl groups of cellulose (A1) are substituted with a long-chain component which is a linear saturated aliphatic acyl group having 12 or more carbon atoms and a short-chain component which is an acyl group having 2 or 3 carbon atoms.

8. A polysaccharide-based resin composition according to claim 1 or 2, in which component (A) is a paramylon-based resin in which at least a portion of the hydrogen atoms of the hydroxyl groups of (A2) paramylon are substituted with a long-chain component which is a linear saturated aliphatic acyl group having 12 or more carbon atoms and a short-chain component which is an acyl group having 2 or 3 carbon atoms.

9. Component (C) is triphenyl phosphate, cresyl di-2,6-xylenyl phosphate, and [(CH ３ ) ２ C ６ H ３ O] ２ P(O)OC ６ H ４ OP (O) [OC ６ H ３ (CH ３ ) ２ ] ２ 4. The polysaccharide-based resin composition according to claim 3, wherein the polysaccharide-based resin composition is one or more phosphoric acid esters selected from the group consisting of compounds represented by the following formula:

10. The polysaccharide resin composition according to claim 1 or 2, wherein the content of component (A) is 25 to 50 mass% relative to 100 mass% of the total content of components (A) to (E).

11. A molded article formed using the polysaccharide resin composition according to claim 1 or 2.

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