WO2023145958A1

WO2023145958A1 - Thermoplastic composition

Info

Publication number: WO2023145958A1
Application number: PCT/JP2023/002990
Authority: WO
Inventors: 良平森
Original assignee: 冨士色素株式会社; Ｇｓアライアンス株式会社
Priority date: 2022-01-31
Filing date: 2023-01-31
Publication date: 2023-08-03

Abstract

The objective of the present invention is to provide: a material that is a cellulose-based composition, is thermoplastic, and does not require the disposal of a solvent or the use of environmentally hazardous substances such as halide-containing substances during the manufacturing process; and a method for producing the same. The thermoplastic composition contains cellulose and a eutectic mixture of monosaccharide and/or disaccharide and hydroxycarboxylic acid. The method for manufacturing a thermoplastic composition comprises: a first step for mixing hydroxycarboxylic acid and monosaccharide and/or disaccharide at a temperature of 150-240 °C; and a second step for mixing the mixture obtained in the first step and cellulose at a temperature of 150-240 °C. In addition, the method for manufacturing a thermoplastic composition comprises a step for mixing cellulose, hydroxycarboxylic acid and monosaccharide and/or disaccharide in an extruder at a temperature of 150-240 °C. The eutectic mixture is preferably a mixture of lactic acid and glucose. In addition, the cellulose content is preferably 0.05-60.0 mass%.

Description

thermoplastic composition

The present invention relates to a cellulose-based thermoplastic composition, specifically a thermoplastic composition containing a eutectic mixture of cellulose and hydroxycarboxylic acids and sugars.

In recent years, biomass-derived materials have been attracting attention against the background of problems such as global environmental conservation and oil depletion. From an environmental point of view, plastic waste is regarded as a problem, and the importance of biodegradable thermoplastic materials is increasing. Cellulose is one of the typical biomass-derived materials and has been widely used. In particular, plant-derived cellulose is attracting attention again from an environmental point of view because it is also biodegradable. Recently, some studies have begun to make new use of such cellulose as a resin-like material.

For example, in Patent Document 1, a cellulosic fibrous material such as pulp is swollen and suspended in the coexistence of a deep eutectic solvent and water, treated with sodium hydroxide or the like, filtered and washed, and then homogenized under high pressure to obtain a nano A method of making a cellulosic material is disclosed. Here, a deep eutectic solvent is a solvent that is liquid at room temperature and is obtained by mixing a hydrogen bond donor compound and a hydrogen bond acceptor compound at a certain ratio. By combining a donor compound and an acceptor compound, a solvent with arbitrary physical properties can be produced, and various combinations have been reported (for example, Non-Patent Document 1). Since deep eutectic solvents generally have excellent solubility, they can finely disperse cellulose and the like, and depending on the combination of raw materials, it is possible to create a colloidal solution of nanocellulose fibers. In Patent Document 1, a urea/choline chloride deep eutectic solvent is used.

In Non-Patent Document 2, bleached birch pulp was dispersed in a reactive or non-reactive deep eutectic solvent such as urea/ammonium thiocyanate, urea/sulfamic acid, or glycerol/aminoguanidine hydrochloride. A technique for producing a wood-based fibrous body by filtering and washing is disclosed. (3), sawdust is dispersed in an imidazole/triethylammonium chloride deep eutectic solvent and treated with succinic anhydride, the resulting suspension is filtered and dried to obtain various mechanical properties. Techniques for making films with According to such a technique, it is possible to produce a resin-like material from a cellulosic material such as paper that has been once discarded, thereby contributing to the reduction of waste.

Japanese Patent Publication No. 2020-518715

As noted above, deep eutectic solvents can be used to obtain resin-like materials from cellulose, but none of the conventional materials thus obtained are thermoplastic, which tends to limit their applications. . In the techniques described in Patent Document 1, Non-Patent Documents 2 and 3, all of the prepared cellulose materials are formed as a film on a filter by filtration. Therefore, not only is the production time-consuming, but there is also the problem of disposal of the deep eutectic solvent. These techniques also use sulfur-containing strong acid compounds such as sulfamic acid and chlorides as deep eutectic solvents, and there is room for improvement from an environmental point of view.

In order to solve the above problems, the present invention is a cellulose-based composition that is thermoplastic and does not require the disposal of solvents or the use of environmentally hazardous substances such as halides in the manufacturing process. The object is to provide a material and a manufacturing method thereof.

The present inventors have made intensive studies to achieve the above object, and found that a composition containing cellulose and a eutectic mixture of monosaccharide and/or disaccharide and hydroxycarboxylic acid has resin-like properties. The inventors have found that they exhibit thermoplasticity and that they can be produced without the disposal of solvents and the use of environmentally hazardous substances, and have completed the present invention.

That is, the present invention provides the following (1) to (11).
(1) A thermoplastic composition containing cellulose and a eutectic mixture of monosaccharides and/or disaccharides and hydroxycarboxylic acids.
(2) The thermoplastic composition of (1), wherein said eutectic mixture is a mixture of lactic acid and glucose.
(3) The thermoplastic composition of (1) or (2), further comprising hemicellulose and/or lignin, and wherein the cellulose is plant-derived cellulose.
(4) The thermoplastic composition according to any one of (1) to (3), containing 0.05 to 60.0% by mass of the cellulose.
(5) The thermoplastic composition according to any one of (1) to (4), wherein the mass ratio of said hydroxycarboxylic acid: said monosaccharide and/or disaccharide is within the range of 1:2 to 6:1.
(6) The thermoplastic according to any one of (1) to (5), further containing one or more substances selected from the group consisting of inorganic fillers, natural thermoplastic resins, synthetic thermoplastic resins, and biodegradable resins. Composition.
(7) a first step of mixing a hydroxycarboxylic acid and a monosaccharide and/or a disaccharide at a temperature of 150 to 240°C; a second step of mixing at a temperature of 240°C;
A method of making a thermoplastic composition, comprising:
(8) The method for producing a thermoplastic composition according to (7), further comprising a third step of kneading and molding the mixture obtained in the second step with an extruder.
(9) A method for producing a thermoplastic composition, comprising the step of mixing cellulose, hydroxycarboxylic acid, and monosaccharide and/or disaccharide in an extruder at a temperature of 150-240°C.
(10) Thermoplastic pellets made of the thermoplastic composition according to any one of (1) to (6).
(11) A molded article made of the thermoplastic composition according to any one of (1) to (6).

Although the thermoplastic composition of the present invention is a cellulose-based composition, it is thermoplastic, so it has good mechanical properties derived from cellulose and is also excellent in moldability. Therefore, it is suitable as a material for various molded articles, and is useful as an industrial material such as thermoplastic pellets. Moreover, it has the advantage of not requiring the disposal of solvent or the use of environmentally hazardous substances such as halogenated compounds in the production process. The thermoplastic composition and the method for producing the same of the present invention can also be applied to cellulose as a raw material containing impurities, such as wood chips such as sawdust and waste paper, so it can also be used for waste treatment. It is also useful from the viewpoint of global environment conservation.

The present invention will be described in detail below based on embodiments.

[Thermoplastic composition]
The present invention is primarily a thermoplastic composition containing cellulose and a eutectic mixture of mono- and/or disaccharides and hydroxycarboxylic acids. First, these components are described in detail. In the present specification, monosaccharides and/or disaccharides are sometimes collectively referred to as "saccharides" and the like.

<Cellulose>
The cellulose constituting the thermoplastic composition of the present invention is not particularly limited, and various known celluloses can be used. Examples include natural cellulose derived from plants, modified cellulose such as cellulose acetate, carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and hydroxypropyl methyl cellulose, and regenerated cellulose, but are not limited to these. Cellulose is not limited to wood pulp, non-wood pulp, and the like, but may be low-purity materials, or may be contained in waste such as sawdust, waste wood, and used paper.

Cellulose is a type of carbohydrate, polysaccharide, and the main component of plant fiber. In plants, it usually exists as lignocellulose, bound or mixed with hemicellulose and lignin. In general, plant-derived cellulose fibers are bundles of 30 to 40 cellulose molecules that form ultra-thin, highly crystalline microfibrils with a diameter of about 3 nm and a length of several hundred nm to several tens of μm. A bundled structure is formed through the soft non-crystalline portion.

The cellulose constituting the thermoplastic composition of the present invention is preferably plant-derived cellulose. The compositions of the present invention exhibit resin-like properties and thermoplastic properties even when the cellulose component is, for example, lignocellulose as described above. Therefore, pulp or the like can be used without being refined, and waste materials such as used paper can also be used as raw materials. In a preferred embodiment of the invention, the cellulose is plant-derived cellulose and further contains hemicellulose and/or lignin.

There are no particular restrictions on plant-derived cellulose. Examples include, but are not limited to, wood, bamboo, hemp, jute, and kenaf, as well as those harvested from crop wastes such as wheat and rice straw, corn, cotton stalks, and sugar cane. Cellulose derived from sawdust, wood chips, waste wood, waste paper, waste cloth, cotton from reforged futons, regenerated pulp, and the like may also be used. Wood-derived cellulose, particularly wood pulp, is preferred from the viewpoints of the composition's appearance, mechanical properties, quality stability, and ease of raw material availability, although it depends on the application of the thermoplastic composition. Wood pulp is less seasonally fluctuating in supply, and is also advantageous in terms of cost.

If desired, hemicellulose and lignin may be removed from the plant-derived cellulose. For example, it is also possible to use kraft pulp that has been chemically treated with caustic soda or the like to remove hemicellulose and lignin to obtain high-purity cellulose.

In the thermoplastic composition of the present invention, some of the hydroxyl groups in the cellulose molecule may be acetylated or carboxylated, and the hydrogen atoms in the hydroxyl groups are metal ions such as sodium and potassium, or ammonium ions. etc. may be substituted.

These celluloses are preferably about 0.05 to 60.0% by mass, more preferably about 0.1 to 50.0% by mass, still more preferably about 0.05 to 60.0% by mass, more preferably about 0.05 to 60.0% by mass, based on 100% by mass of the total thermoplastic composition of the present invention. It is contained in an amount of about 2 to 40.0% by mass. The thermoplastic composition of the present invention develops a cellulose-derived texture and excellent mechanical strength even when the cellulose content is as small as about 0.05% by mass. Moreover, if the content of cellulose is about 60.0% by mass or less, sufficient thermoplasticity is ensured. In addition, when the thermoplastic composition of the present invention contains hemicellulose and/or lignin, since these components are substances constituting lignocellulose, the amount thereof shall be included in the above cellulose content.

Here, the cellulose content in the total 100% by mass of the thermoplastic composition of the present invention is 0 when improving the molding processability of the thermoplastic composition or when producing a small amount with a mixing device having a low shear force. 0.05 to 20.0% by mass, preferably 0.1 to 10.0% by mass, more preferably 0.2 to 5.0% by mass, and particularly preferably about 0.4 to 2.0% by mass. On the other hand, from the viewpoint of improving the heat resistance and mechanical properties of the thermoplastic composition or utilizing more cellulose waste materials, it is about 5.0 to 60.0% by mass, for example 10.0 to 50.0% by mass, Among them, it is preferably about 15.0 to 40.0% by mass, more preferably about 18.0 to 30.0% by mass, particularly about 20.0 to 25.0% by mass.

<eutectic mixture>
The thermoplastic composition of the present invention contains a eutectic mixture of hydroxycarboxylic acid and saccharide together with the cellulose. This eutectic mixture acts like a deep eutectic solvent and can loosen cellulose to near nanofiber level and even dissolve or finely disperse to form a nearly homogeneous mixture. The eutectic mixture can also be mixed with cellulose or the like to form a composition that is solid at room temperature and thermoplastic. This is an unexpected phenomenon that does not occur with deep eutectic solvents such as the aforementioned imidazole/ammonium chloride system. The reason why the composition of the present invention becomes such a thermoplastic material is unknown, but it is conceivable that the hydroxycarboxylic acid and the saccharide form a eutectic and simultaneously interact with cellulose. However, the invention is not limited to any particular theory.

In the present invention, the eutectic mixture constitutes the thermoplastic composition together with cellulose as described above, and there is no need to separate and remove the cellulose material after preparation (for example, as in the preparation method described in Non-Patent Document 2). . Therefore, labor and costs for separation, waste solvent treatment, etc. can be reduced. The eutectic mixture in the thermoplastic composition of the present invention is also composed of hydroxycarboxylic acids and monosaccharides and/or disaccharides, both of which are natural products that do not contain halogens. It can be said that it is an excellent material that does not apply a load.

(Hydroxycarboxylic acid)
In the present invention, the hydroxycarboxylic acid may be any compound as long as it forms a eutectic mixture with monosaccharides and/or disaccharides, and the type thereof is not particularly limited. Examples are glycolic acid, lactic acid, tartronic acid, glyceric acid, hydroxybutyric acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, γ-hydroxybutyric acid, malic acid, tartaric acid, citramaric acid, citric acid, isocitric acid, leucic acid, mevalonic acid. , pantoic acid, ricinoleic acid, ricineraidic acid, cerebronic acid, quinic acid, and shikimic acid; , orceric acid, gallic acid, mandelic acid, benzilic acid, atrolactinic acid, cinnamic acid, melilotic acid, phloletic acid, coumaric acid, umberic acid, caffeic acid, ferulic acid, and aromatic hydroxycarboxylic acids such as sinapic acid. include, but are not limited to. Depending on the combination with monosaccharide and/or disaccharide, it is also possible to use multiple hydroxycarboxylic acids in combination.

As the hydroxycarboxylic acid, a compound having one hydroxy group and one carboxy group in the molecule is preferable, and an aliphatic hydroxycarboxylic acid is preferable. More preferably, aliphatic hydroxycarboxylic acids having 2 to 4 carbon atoms are used. Such hydroxycarboxylic acids easily form a deep eutectic solvent with monosaccharides and disaccharides, and their composition with cellulose also exhibits good thermoplasticity. Lactic acid is particularly preferred. Lactic acid may be in any form, such as D-form, L-form, and DL-form.

(monosaccharide)
The monosaccharide used in the present invention may be any compound as long as it forms a eutectic mixture with hydroxycarboxylic acid, and the type thereof is not particularly limited. aldoses such as glyceraldehyde, erythrose, threose, ribose, lyxose, xylose, arabinose, allose, talose, gulose, glucose, altrose, mannose, galactose, and idose; Ketoses such as, but not limited to, fructose, sorbose, and tagatose. Depending on the combination with hydroxycarboxylic acid, it is also possible to use multiple monosaccharides in combination.

(disaccharide)
The disaccharide in the present invention is also not particularly limited. Examples include, but are not limited to, sucrose (sucrose), lactulose, lactose (milk sugar), maltose (maltose), trehalose, cellobiose, and the like. It is also possible to use two or more disaccharides together, or to use a monosaccharide and a disaccharide together.

Among the above sugars, monosaccharides are preferred. Aldoses are more preferably used, and aldohexoses are more preferably used. These monosaccharides easily form a eutectic mixture with hydroxycarboxylic acid, and the composition with cellulose also exhibits good thermoplasticity. Among aldohexoses, glucose, allose, mannose, galactose, etc., and particularly glucose (grape sugar) are preferred. Specifically, the eutectic mixture constituting the thermoplastic composition of the present invention is particularly preferably a mixture of lactic acid and glucose. Although monosaccharides such as glucose also have several optical isomers, any structure can be used in the present invention.

<Composition of thermoplastic composition>
In the thermoplastic composition of the present invention, the contents of hydroxycarboxylic acid and sugar are not particularly limited, and for example, the mass ratio of hydroxycarboxylic acid: sugar can be selected from the range of 1:4 to 99:1. be. However, in the present invention, the mass ratio of hydroxycarboxylic acid: monosaccharide and/or disaccharide is preferably within the range of 1:2 to 6:1, more preferably within the range of 1:1 to 4:1, and still more preferably should be in the range of 2:1 to 3:1. If the ratio of the two is within this range, a eutectic mixture is likely to be formed, and the composition with cellulose also exhibits good thermoplasticity. In a particularly preferred embodiment of the invention, lactic acid and glucose are contained in a weight ratio of 1:1 to 4:1, especially in a weight ratio of 2:1 to 3:1.

A preferred embodiment of the thermoplastic composition of the present invention contains 0.05 to 20.0% by mass of cellulose and 20.0% by mass of hydroxycarboxylic acid relative to the total 100% by mass of cellulose, hydroxycarboxylic acid and saccharides. 0 to 99.0% by mass and 1.0 to 80.0% by mass of saccharide; more preferably 0.1 to 5.0% by mass of cellulose and 50.0 to 90.0% by mass of hydroxycarboxylic acid. 0% by mass, saccharides in an amount of 5.0 to 50.0% by mass; more preferably 0.2 to 2.0% by mass of cellulose, 60 to 80% by mass of hydroxycarboxylic acid, and 20 to 20% by mass of saccharides It is contained in an amount of 40% by mass. With such a composition, the thermoplastic composition of the present invention is particularly excellent in texture and moldability. It can be a thermoplastic composition that

Another preferred embodiment of the thermoplastic composition of the present invention is 5 to 60% by mass of cellulose and 20 to 80% by mass of hydroxycarboxylic acid relative to the total 100% by mass of cellulose, hydroxycarboxylic acid, and three sugars. %, sugars in an amount of 5 to 50% by mass; more preferably 10 to 50% by mass of cellulose, 30 to 60% by mass of hydroxycarboxylic acid, and 10 to 40% by mass of sugars; It preferably contains 20 to 45% by weight of cellulose, 35 to 50% by weight of hydroxycarboxylic acid, and 15 to 30% by weight of sugar. With such a composition, the thermoplastic composition of the present invention is particularly excellent in texture, heat resistance, mechanical properties and the like. It can be a thermoplastic composition that melts at temperatures as low as 210° C. or solidifies after cooling.

<Additives>
The thermoplastic composition of the present invention contains one or more selected from the group consisting of inorganic fillers, natural thermoplastic resins, synthetic thermoplastic resins, and biodegradable resins, in addition to the cellulose, hydroxycarboxylic acid, and sugars described above. It may further contain substances. By containing the inorganic filler, it is possible to control the mechanical properties such as hardness and strength of the thermoplastic composition, as well as the physical properties such as heat resistance. Further, by containing various resins, it is possible to control the melting/solidifying temperature and physical properties of the thermoplastic composition.

(Inorganic filler)
There are no particular restrictions on the inorganic filler to be blended in the thermoplastic composition of the present invention. Examples include carbonates, sulfates, silicates, phosphates, borates, oxides of calcium, magnesium, aluminum, titanium, iron, zinc, barium, etc., or powdery hydrates thereof. Specific examples include calcium carbonate, magnesium carbonate, zinc oxide, titanium oxide, silica, alumina, clay, talc, kaolin, aluminum hydroxide, magnesium hydroxide, aluminum silicate, magnesium silicate, calcium silicate, Aluminum sulfate, magnesium sulfate, calcium sulfate, magnesium phosphate, barium sulfate, silica sand, carbon black, zeolite, molybdenum, diatomaceous earth, sericite, shirasu, calcium sulfite, sodium sulfate, potassium titanate, bentonite, wollastonite, dolomite, Examples include, but are not limited to, graphite and the like. The inorganic filler may be synthetic or derived from natural minerals, and may be contained singly or in combination of two or more. Among these, calcium carbonate, clay, talc, kaolin and the like are preferable from the viewpoint of safety and cost. In particular, calcium carbonate is commercially available with various particle sizes and particle shapes, and it is possible to select the type according to the physical properties of the desired thermoplastic composition, which is preferable. The use of eggshell-derived calcium carbonate from food factories can also contribute to the reduction of waste.

When an inorganic filler is added to the thermoplastic composition of the present invention, the content is not particularly limited. Further, it is preferably about 20 to 200% by mass, particularly about 30 to 100% by mass. With such a blending amount, physical properties such as hardness can be controlled without impairing the melt processability of the thermoplastic composition.

(resin)
Natural thermoplastic resins, synthetic thermoplastic resins, and biodegradable resins to be blended in the thermoplastic composition of the present invention are also not particularly limited. Examples include polyethylene resins, polypropylene resins, polymethyl-1-pentene, polyolefin resins such as ethylene-cyclic olefin copolymers; ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, ethylene-methacrylic acid Copolymer, metal salt of ethylene-(meth)acrylic acid copolymer (ionomer), ethylene-alkyl acrylate copolymer, ethylene-alkyl methacrylate copolymer, maleic acid-modified polyethylene, maleic acid-modified polypropylene Functional group-containing polyolefin resins such as; nylon-6, nylon-6,6, nylon-6,10, nylon-6,12 and other polyamide resins; polyethylene terephthalate and its copolymers, polyethylene naphthalate, polybutylene Aromatic polyester resins such as terephthalate, aliphatic polyester resins such as polyvinyl acetate, polybutylene succinate, polylactic acid, poly(3-hydroxybutyrate/3-hydroxyvalerate) copolymer (PHBV) Thermoplastic polyester resins such as; acrylic resins such as poly (meth) acrylic acid (ester) and polyacrylonitrile; polycarbonate resins such as aromatic polycarbonates and aliphatic polycarbonates; atactic polystyrene, syndiotactic polystyrene, acrylonitrile-styrene (AS) copolymers, acrylonitrile-butadiene-styrene (ABS) copolymers and other polystyrene resins; polyvinyl chloride, polyvinylidene chloride and other polyvinyl chloride resins; polyphenylene sulfide; polyether sulfone, polyether ketone, polyether-based resins such as polyetheretherketone; and various known thermoplastic resins such as polyvinyl alcohol, rosin, cellulose acetate-based thermoplastic resins, petroleum hydrocarbon resins, and coumarone-indene resins. Not limited. A plurality of types of thermoplastic resins can also be used in combination. It also contains elastomer components such as styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-butadiene-ethylene copolymer, styrene-isoprene-ethylene copolymer, acrylonitrile-butadiene copolymer, and fluoroelastomer. It's okay to be

By blending such resins, the physical properties of the thermoplastic composition of the present invention can be changed in various ways. For example, by adding rosin or the like, the water resistance of the thermoplastic composition can be improved. Moreover, by blending a biodegradable resin such as polylactic acid or PHBV, it is possible to promote biodegradation when the thermoplastic composition is discarded, thereby contributing to the environment.

From the viewpoint of maximizing the physical properties and workability of the thermoplastic composition of the present invention, as well as the texture derived from cellulose, it is possible to choose not to blend the above thermoplastic resin. In addition, when these thermoplastic resins are blended, the content is 5 to 120% by mass, further 10 to 100% by mass with respect to the total 100% by mass of cellulose, hydroxycarboxylic acid, and three sugars, In particular, it is preferably about 20 to 80% by mass.

Another preferred embodiment of the thermoplastic composition of the present invention comprises 5 to 40% by weight of cellulose, 5 to 40% by weight of hydroxycarboxylic acid, 3 to 25% by weight of sugar, It contains 20 to 80% by mass of resin and filler; more preferably 10 to 35% by mass of cellulose, 10 to 35% by mass of hydroxycarboxylic acid, 5 to 20% by mass of sugar, and 30 to 30% by mass of resin and filler. It contains 70% by mass; more preferably 15 to 30% by mass of cellulose, 15 to 30% by mass of hydroxycarboxylic acid, 7 to 15% by mass of sugar, and 35 to 60% by mass of resin or filler. contains. With such a composition, it is possible to obtain a thermoplastic composition that is particularly excellent in texture, heat resistance, water resistance, mechanical properties, and the like.

(Other additives)
If desired, the thermoplastic composition of the present invention may contain additives other than those described above. Other additives include, for example, colorants, lubricants, coupling agents, fluidity modifiers (fluidity modifiers), cross-linking agents, dispersants, antioxidants, ultraviolet absorbers, flame retardants, stabilizers, and electrifying agents. Inhibitors, foaming agents, plasticizers, starches, casein and the like include, but are not limited to. These additives may be used alone or in combination of two or more. Further, it may be blended in the kneading step described later, or may be blended in the raw material components in advance before the kneading step. For example, the coupling agent may be added in advance to the surface of the cellulose or inorganic filler.

In the thermoplastic composition of the present invention, the content of these other additives can be arbitrarily set according to the desired physical properties and processability, but the total of cellulose, hydroxycarboxylic acid, and sugars 100% by mass, each of these other additives is about 0 to 10% by mass, particularly about 0.05 to 5% by mass, and the total amount of the other additives is 20% by mass or less, for example, 0.5% by mass. A ratio of 05 to 20% by mass is preferable.

[Method for producing thermoplastic composition]
The thermoplastic composition of the present invention can be produced by mixing each component. The production method is not particularly limited, for example, cellulose, hydroxycarboxylic acid, and sugars, and additives such as inorganic fillers and other resin components may be kneaded at the same time. It is also possible to knead the two components first and then add and knead the other components.

Here, in order to improve the molding processability of the thermoplastic composition, or to prepare a small amount using a mixing apparatus with a low shearing force, for example, hydroxycarboxylic acid and sugar are melt-kneaded, and then cellulose is kneaded. preferable. Since hydroxycarboxylic acid and sugar can form a eutectic mixture, by mixing these two components first, it is possible to proceed with the subsequent mixing at a mild temperature and under low shear, which reduces energy consumption. In addition to being able to reduce it, it is also possible to prevent deterioration of organic matter at high temperatures.

The present invention also provides a first step of mixing a hydroxycarboxylic acid and a monosaccharide and/or a disaccharide at a temperature of 150 to 240° C., and Also included is a method for producing a thermoplastic composition (hereinafter, this production method may be referred to as “manufacturing method-A”), including a second step of mixing at a temperature of 240°C. For example, production method-A is effective when producing a thermoplastic composition having a cellulose content of about 0.05 to 20.0 mass % of the total.

In the manufacturing method of the present invention, such as manufacturing method-A, there is no particular limitation on the method of mixing each component. Examples include a method of mixing at a temperature of 150 to 240°C, particularly 160 to 200°C, using a general kneading device such as an extruder, kneader, Banbury mixer, planetary mixer, Henschel mixer, and hot rolls. is not limited to Small batches can be mixed in a stirred flask as described below.

However, when mixing on a scale above a certain level (not only in production method-B described later, but also in production method-A), it is preferable to use an extruder, particularly a twin-screw extruder. In the case of an extruder, each component can be uniformly dispersed by applying a high shearing force during mixing, and cellulose is added in the post-extrusion stage to perform the first step and the second step in the same manner. It is also possible to do it with a device. Of course, the first step and the second step may be performed, for example, by separate apparatuses after a period of time. It is also possible to carry out the first step and the second step with a kneader and further knead and mold the resulting mixture with an extruder.

In one embodiment of the production method-A of the present invention, for example, the first step and the second step are performed with a twin-screw extruder or a kneader, and the resulting mixture is extruded with a single-screw or twin-screw extruder. In this way, the thermoplastic composition of the present invention is extruded, for example, in the form of a strand, and cut into prisms or cylinders having a size of about 2 to 5 mm square with a pelletizer or the like to obtain a thermoplastic composition having the above composition. can be obtained in the form of pellets. The present invention also includes a method for producing a thermoplastic composition, further comprising a third step of kneading and molding the mixture obtained in the second step with an extruder.

The thermoplastic composition of the present invention can also be produced by simultaneously kneading cellulose, hydroxycarboxylic acid, and sugars (this production method may be referred to as "production method-B"). can. For example, when producing a thermoplastic composition having a cellulose content of about 5 to 60% by mass of the total, it is advantageous to adopt production method-B using a high-shear mixing device. There are no particular restrictions on the high-shear mixing device, and examples thereof include extruders, kneaders, Banbury mixers, etc., but extruders, particularly twin-screw extruders, are preferred. According to such a mixing device, hydroxycarboxylic acid and sugar are mixed by high shearing force, and a deep eutectic solvent can be formed even in the presence of other components, so the step of pre-mixing only these two components is further omitted. becomes possible.

The present invention also includes a method for producing a thermoplastic composition comprising the step of mixing cellulose, hydroxycarboxylic acid and monosaccharide and/or disaccharide in an extruder at a temperature of 150-240°C. According to such production method-B, it becomes easy to produce a thermoplastic composition having excellent heat resistance and mechanical properties, and it becomes possible to utilize a larger amount of cellulose waste material.

There are no particular restrictions on the extruder used in Manufacturing Method-B. Although a twin screw extruder is preferred, it is not so limited and any type of twin screw extruder can be used. The kneading/extrusion conditions are also not limited, and can be carried out at a temperature of, for example, 150 to 240°C, especially 160 to 230°C, particularly 170 to 210°C. In addition, components such as inorganic fillers and resins may be kneaded simultaneously with the three of cellulose, hydroxycarboxylic acid and saccharides, or may be kneaded into a mixture of these three afterward. For example, it is also possible to knead only the above three components or some of the other components by production method-B using an extruder, and then knead the remaining components with a mixing device such as an extruder or a kneader.

In manufacturing method-B, it is possible to directly extrude the kneaded product from an extruder to form a molded product or to form pellets. Moreover, the obtained mixture may be subjected to the same step as the third step in the production method-A. For example, the mixture obtained in the production method-B is extruded in a strand shape using a single-screw or twin-screw extruder, and cut into prisms or cylinders having a size of about 2 to 5 mm square with a pelletizer or the like. A thermoplastic composition of such composition can also be obtained in the form of pellets.

[Molding]
The present invention further includes thermoplastic pellets comprising the thermoplastic composition described above. The thermoplastic composition of the present invention is generally 50 to 230° C. as described above, specifically 60 to 200° C., further 70 to 150° C. when the cellulose content is about 0.05 to 20.0% by mass. , Especially at a temperature of about 70 to 100 ° C., and when the cellulose content is about 5 to 60% by mass, it is melted or solidified at a temperature of 150 to 240 ° C., further 160 to 230 ° C., particularly 170 to 210 ° C. Therefore, it has excellent moldability. Therefore, the thermoplastic pellets of the present invention are suitable as a thermoplastic polymeric material.

The thermoplastic composition of the present invention has good thermoplasticity as described above, and can be molded into various shapes. The present invention also includes moldings comprising the thermoplastic compositions described above. There are no particular restrictions on the shape and size of these molded bodies, and they may be sheet-shaped, tubular, strand-shaped, or any other shape depending on the purpose. The molding method is also not limited, and any molding method such as extrusion molding, injection molding, roll molding, transfer molding, and blow molding can be used. For example, the thermoplastic pellets of the present invention described above may be molded into a desired shape using an extruder or an injection molding machine, and the thermoplastic composition may be extruded without pelletization to form a sheet or tube. It can be molded. It is also possible to combine with other materials by calender molding or the like.

There are no particular restrictions on the uses of the thermoplastic composition and molded article of the present invention. For example, it can be used as a polymer material for daily necessities such as toys, toothbrushes, and bath products, housings for home electric appliances, and transportation equipment such as automobiles and trains. In particular, when a refined product such as kraft pulp is used as a cellulose raw material, it can be used for medical purposes and food products. Cellulose, hydroxycarboxylic acid, monosaccharide, and disaccharide are all highly safe substances, so the thermoplastic composition of the present invention comprising these components is suitable for medical and food applications. The thermoplastic composition of the present invention can also be said to be a natural product-derived material with a different concept from conventional biodegradable resins, and can be used as an additive to other materials for the purpose of increasing the biomass content.

Hereinafter, the present invention will be described more specifically based on examples. It should be noted that these Examples are intended to provide specific aspects and implementations in order to facilitate an understanding of the concept and scope of the present invention disclosed herein and recited in the appended claims. The present invention is in no way limited to these examples, which are provided for illustrative purposes only.

[Example 1]
(First Step/Manufacturing Method-A)
100 g of lactic acid and 40 g of glucose were placed in a flask equipped with a stirrer and stirred at a temperature of 150-200° C. for 30 minutes. The resulting mixture was liquid at room temperature and was a 100% natural deep eutectic solvent.

(Second step/manufacturing method-A)
100 g of the mixture obtained in the first step was placed in a flask equipped with a stirrer and heated to 150-200°C. 0.5 g of pulp was added thereto and stirred at about 150 to 200° C. for 1 hour or longer to obtain a substantially uniform brown liquid. Heating and stirring at the above temperature were carried out for a total of 8 hours. When the liquid was then transferred onto a clean aluminum plate, it solidified into a solid.

(Properties of composition)
The solid obtained in the second step had a resin-like appearance and feel. When this solid was struck with a clean hammer, it turned into powder. This powdery material melted at a temperature of around 150° C. and turned into a solid again when cooled to around room temperature. Also, this powdery material could be made into a dumbbell-shaped test piece by injection molding. That is, it was shown that the compositions obtained in this example were thermoplastic.

In addition, in the first step, a simple experiment similar to Example 1 was performed using other deep eutectic solvents instead of lactic acid and glucose. Thermoplasticity was not expressed either (Comparative Example 1). Although it is not possible to make a definite statement because the temperature control during mixing was not precisely controlled, the thermoplastic material of the present invention cannot be obtained simply by heating and mixing cellulose with a deep eutectic solvent. is suggested.

[Example 2]
The powdery material (thermoplastic composition) obtained in Example 1 and starch were charged into a small twin-screw extruder at a mass ratio of 7:3, and kneaded and extruded at 80 to 120 ° C. to prepare pellets. . A dumbbell-shaped test piece could be produced from the obtained pellets by injection molding in the same manner as in Example 1.

[Example 3]
The powder (thermoplastic composition) obtained in Example 1 and talc were put into a small twin-screw extruder at a mass ratio of 6:4, and pellets were produced in the same manner as in Example 2. Dumbbell-shaped test pieces could be produced from the obtained pellets by injection molding in the same manner as in Examples 1 and 2.

[Example 4]
The pellets obtained in Example 2 and poly(3-hydroxybutyrate/3-hydroxyvalerate) (PHBV, biodegradable resin) were charged into a small twin-screw extruder at a mass ratio of 1:1, Pellets were produced in the same manner as in Example 2. Dumbbell-shaped test pieces could be produced from the obtained pellets by injection molding in the same manner as in Examples 1-3.

[Example 5]
The pellets obtained in Example 3 and gum rosin were put into a small twin-screw extruder at a mass ratio of 8:2, and pellets were produced in the same manner as in Example 3. Dumbbell-shaped test pieces could be produced from the obtained pellets by injection molding in the same manner as in Examples 1-4.

[Example 6]
Pellets were produced in the same manner as in Example 5 using lignin (Vanirex (registered trademark) CN manufactured by Nippon Paper Industries Co., Ltd.) instead of gum rosin. Dumbbell-shaped test pieces could be produced from the obtained pellets by injection molding in the same manner as in Examples 1-5.

[Example 7]
40 parts by mass of cedar wood powder, 50 parts by mass of lactic acid, 25 parts by mass of glucose, and 50 parts by mass of cedar wood powder in a twin-screw extruder (twin-screw kneading extruder manufactured by Technobel, φ 15 mm, L / D = 50) Part of talc was added and extruded into strands while being kneaded at a set temperature of 160 to 220°C (a thermoplastic composition was prepared by the above-described production method-B). The strand was then cut by a pelletizer into pellets of the thermoplastic composition.

The obtained pellets were then put in an injection molding machine (HAAKE Process 11 manufactured by Thermo Fisher Scientific), and at 180 to 220 ° C., JIS K7171 (ISO 178) bending test specimens (80 × 10 × 4 mm ) and a dumbbell-shaped specimen for JIS K7161-2 tensile test. It was found that the composition of this example was thermoplastic and exhibited good molding processability in spite of containing a large amount of cellulose component.

Next, using these three test pieces, a bending test (test speed: 2 mm/min) according to JIS K7171 and a tensile test (tensile speed: 5 mm/min) according to JIS K7161-2 were performed to evaluate the mechanical strength. Water resistance was also evaluated. The water resistance was evaluated based on the following criteria by placing the prepared thermoplastic resin pellets and dumbbell test pieces in a glass beaker filled with water and visually observing changes in shape.
(Water resistance evaluation criteria)
○: No change in shape was observed △: The shape of the test piece changed, but it did not collapse ×: The test piece collapsed in water and the shape was not retained are shown in Table 1 below together with the formulation of

[Examples 8 to 13]
The same procedure as in Example 7 was performed using rosin or PHBV along with the ingredients used in Example 7. Table 1 shows the formulation and evaluation results of each thermoplastic composition.

From the above examples, it can be seen that the compositions of the present invention containing cellulose and eutectic mixtures of hydroxycarboxylic acids and sugars exhibit thermoplastic properties and can be hot melt kneaded with various materials to provide various thermoplastic, resin-like materials. shown that it can be done. In view of the fact that simply mixing cellulose with a deep eutectic solvent did not yield a thermoplastic material (Comparative Example 1), the present invention is believed to be a thermoplastic material exhibiting unexpected properties.

[Examples 14 to 19]
The same operations as in Examples 8-13 were performed using polypropylene (PP) or polyethylene (PE) instead of rosin or PHBV. Table 2 shows the formulation of the thermoplastic composition and the evaluation results.

It was shown that the thermoplastic composition of the present invention can also contain general-purpose resins such as polypropylene and polyethylene, thereby improving physical properties such as mechanical properties and water resistance. As described above, the thermoplastic composition of the present invention can be blended with a large amount of various resins, inorganic fillers, and the like, thereby improving physical properties such as water resistance and reducing costs. be. For example, in the same manner as in Examples 8 to 10, it has been confirmed that up to 175 parts by mass of rosin can be blended to improve water resistance.

As described above, the thermoplastic composition of the present invention exhibits thermoplasticity even when a composition containing a large amount of cellulose is used, and is useful for recycling cellulosic waste materials. It can also be mixed with petroleum-based resins such as polyethylene to increase the degree of biomass. The thermoplastic composition of the present invention can also be mixed with biodegradable resins such as PHBV to increase the usage rate of waste materials and reduce costs without deteriorating physical properties, so to speak, it can be used like a bulking agent. is also possible. Moreover, the thermoplastic composition of the present invention does not require the disposal of solvents or the use of environmentally hazardous substances such as halogenated compounds during the production process. In view of these points, the effects of the present invention are remarkable.

Claims

A thermoplastic composition containing cellulose and a eutectic mixture of monosaccharides and/or disaccharides and hydroxycarboxylic acids.
The thermoplastic composition according to claim 1, wherein the eutectic mixture is a mixture of lactic acid and glucose.
The thermoplastic composition according to claim 1 or 2, further comprising hemicellulose and/or lignin, and wherein the cellulose is plant-derived cellulose.
The thermoplastic composition according to claim 1 or 2, containing 0.05 to 60.0% by mass of the cellulose.
The thermoplastic composition according to claim 1 or 2, wherein the mass ratio of said hydroxycarboxylic acid: said monosaccharide and/or disaccharide is within the range of 1:2 to 6:1.
The thermoplastic composition according to claim 1 or 2, further comprising one or more substances selected from the group consisting of inorganic fillers, natural thermoplastic resins, synthetic thermoplastic resins, and biodegradable resins.
A first step of mixing hydroxycarboxylic acid and monosaccharide and/or disaccharide at a temperature of 150 to 240 ° C., and mixing the mixture obtained in the first step and cellulose at a temperature of 150 to 240 ° C. a second step of mixing with
A method of making a thermoplastic composition, comprising:
The method for producing a thermoplastic composition according to claim 7, further comprising a third step of kneading and molding the mixture obtained in the second step with an extruder.
A method for producing a thermoplastic composition, which includes a step of mixing cellulose, hydroxycarboxylic acid, and monosaccharide and/or disaccharide in an extruder at a temperature of 150 to 240°C.
A thermoplastic pellet made of the thermoplastic composition according to claim 1 or 2.
A molded article made of the thermoplastic composition according to claim 1 or 2.