Regenerated natural feedstock

Abstract

Provided is a regenerated natural raw material such as regenerated wood, which has excellent machinability without deteriorating strength and water resistance, has little burden on the environment, can be easily manufactured, and contributes to the effect of solving the problem of resource exhaustion. As a regenerated natural raw material, for example, a regenerated natural raw material containing at least a body material containing at least one powder derived from a biomass resource having a particle size of 2 mm or less, a cutting-improving material containing a thermoplastic solid having a melting point of 40 DEG C or higher, and a binder, the regenerated natural raw material is formed into a predetermined shape, such as a rod shape, a plate shape, a tube shape, a block shape, a sheet shape and the like, in a mass ratio of a body material / a cutting improving material / a binding material = 20-65 / 15-55 / 10-50.

Description

Technical Field

[0001] The present specification relates to a recycled natural raw material such as recycled wood which is excellent in moldability and machinability after molding and contributes to the effect of solving the problem of resource depletion. Background Art

[0002] Conventionally, as a substitute for wood, a material obtained by kneading an easily moldable raw material such as resin and a physical material such as clay mineral powder has been proposed.

[0003] For example: 1) As a composite material suitable for extrusion molding for improving the elongation, uneven fluidity, or surface roughness of a molded body derived from the properties of a resin, there is known a composite material which is a composition comprising polyethylene (A) having specific properties, a cellulose-based powder (B), and a specific wax (C), and the weight ratio thereof is in the range of (A) / (B) / (C)=25 to 89 / 10 to 70 / 0.5 to 17.5 (a total of 100 parts by weight) (see, for example, Patent Document 1); 2) In order to improve moldability, strength, and water resistance and to provide a homogeneous and higher-quality wood-based molded body, there is known a wood-based molded body which is obtained as follows: a wood-based material is subjected to After heating and pressurizing, the pressure is rapidly reduced, blasted and dried to obtain a powdered blasted material, water is added to the obtained blasted material, at least a resin in a fluid state and a powdered wood-based material are mixed with the aforementioned blasted material to which water is added and molded, thereby obtaining (for example, refer to patent document 2); 3) As a wood resin pellet having low melt viscosity, excellent moldability, and a good appearance close to natural wood, etc., and can obtain a molded product with suppressed discoloration (burning) during molding and excellent physical properties, a wood resin pellet is known, which contains: 70 to 91 parts by weight of wood powder, and 1 to 15 parts by weight of a wax material having a melting point between 40 and 100°C (for example, refer to patent document 3), etc.

[0004] The composite materials, wood-based molded bodies, wood resin pellets, etc. disclosed in the above-mentioned patent documents 1 to 3 are produced for the purpose of easy molding, preventing burning during molding, and obtaining an appearance close to natural wood, without considering the ease of processing after molding such as ease of cutting and ease of cutting, and the current situation is that further improvement and modification are urgently desired. In addition, when using petroleum-derived materials, the effect of solving the problem of resource depletion is poor.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2000-103915 (claims, examples, etc.)

[0008] Patent Document 2: Japanese Patent Application Publication No. 2006-272696 (claims, examples, etc.)

[0009] Patent Document 3: Japanese Patent Application Publication No. 2011-236410 (claims, examples, etc.) Summary of the invention

[0010] Problem that the invention aims to solve

[0011] The present disclosure is made in order to eliminate the above-mentioned existing problems, and its purpose is to provide recycled natural raw materials such as recycled wood that have excellent machinability, low environmental load, easy manufacturing, and contribute to solving the problem of resource depletion without compromising strength and water resistance.

[0012] Solutions for solving problems

[0013] The present inventors have conducted in-depth research on the above-mentioned existing issues and found that the above-mentioned target regenerated natural raw material can be obtained by at least comprising a physical material containing powder derived from biomass resources with a particle size below a specific value, a cutting improvement material containing a thermoplastic solid with specific physical properties, and a binding material in a specified ratio and molded into a specified shape, etc., thereby completing the present disclosure.

[0014] That is, the regenerated natural raw material disclosed in the present invention is characterized in that it contains at least: a physical material comprising at least one powder of a biomass resource source with a particle size of less than 2 mm; a cutting improvement material comprising a thermoplastic solid with a melting point of more than 40°C; and a binding material, wherein the regenerated natural raw material is composed of a ratio of physical material / cutting improvement material / binding material = 20 to 65 / 15 to 55 / 10 to 50 and is molded into a specified shape.

[0015] The cutting improving material preferably has a natural origin index defined in ISO 16128 of 50% or more.

[0016] The aforementioned binder material is preferably cellulose or a cellulose derivative.

[0017] The cellulose derivative is preferably ammonium carboxymethylcellulose.

[0018] The aforementioned regenerated natural material is preferably formed into a stick-shaped regenerated natural material, and the stick-shaped regenerated natural material is preferably further processed to form a shaft for a writing instrument or a pencil shaft.

[0019] Effects of the Invention

[0020] According to the present disclosure, it is possible to provide a recycled natural raw material such as recycled wood which has excellent machinability, has little environmental load, can be easily manufactured, and contributes to solving the problem of resource depletion without sacrificing strength and water resistance.

[0021] The objects and effects of the present disclosure are realized and attained particularly by using the constituent elements and combinations pointed out in the claims.Both the above general description and the following detailed description are exemplary and explanatory and do not limit the present disclosure described in the claims. DETAILED DESCRIPTION

[0022] The following is a detailed description of the embodiments of the present disclosure. However, the scope of protection of the present disclosure is not limited to the embodiments described in detail below, and it should be noted that it involves the inventions and their equivalents recorded in the claims. In addition, the present disclosure can be implemented based on the contents disclosed in this specification and the technical common sense in the field (including conventional technical selections and obvious features).

[0023] The regenerated natural raw material disclosed in the present invention is characterized in that it contains at least: a physical material comprising at least one powder of a biomass resource source with a particle size of less than 2 mm; a cutting improvement material comprising a thermoplastic solid with a melting point of more than 40°C; and a binding material, wherein the regenerated natural raw material is composed of a mass ratio of physical material / cutting improvement material / binding material = 20 to 65 / 15 to 55 / 10 to 50 and is molded into a specified shape.

[0024] The physical material used in the present disclosure includes at least one kind of powder selected from biomass resource sources having a particle size of 2 mm or less.

[0025] As biomass resources in the present disclosure, for example, any of waste resources, unused resources, and production resources recorded and classified in the NEDO (New Energy and Industrial Technology Development Organization, National Research and Development Corporation New Energy and Industrial Technology Development Organization) Renewable Energy Technology White Paper, etc., is used, without particular limitation. From the perspective of limited use and great advantages in application, waste resources and unused resources are suitable. Among waste resources and unused resources, wood-based biomass, food waste, and agricultural residue-based biomass are preferred for the ease of obtaining powder or pulverizing.

[0026] As the woody biomass, lumber mill residues, construction timber, forest land residues, thinning timber, unused trees, trees, bamboo, and the like are used.

[0027] As the above-mentioned trees, for example, trees of natural origin such as broad-leaved trees and coniferous trees are used, and there is no particular limitation. As specific trees, for example, fir, pine, larch, red pine, Abies kaempferi, cypress, beech, horse chestnut, oak, mizana, taro, linden, birch, spring elm, willow, hemlock, etc. Among the materials selected from these trees, fir, cypress, beech, horse chestnut, mizana, etc. are particularly suitable from the aspect of easy availability.

[0028] In addition, examples of the above-mentioned bamboo include naturally derived mottled bamboo, moso bamboo, purple bamboo, arhat bamboo, tortoise shell bamboo, small-leaved qinsi bamboo, yeping bamboo, root curved bamboo, Tang bamboo, square bamboo, cold bamboo, arrow bamboo, Sichuan bamboo, etc. Moso bamboo, etc. are preferably used because of their large stock volume and easy availability.

[0029] As the above-mentioned food waste, for example, the screening of raw materials of food, the waste generated in the manufacturing process, kitchen waste, etc. are used, and there is no particular limitation. In terms of the difference between the edible part and the inedible part, the inedible part is preferably used from the aspect of lack of versatility. As specific inedible parts of food waste, tea dregs, coffee dregs, peach shells, walnut shells, corn cobs, vegetable peels or seeds or cores can be cited.

[0030] As the agricultural residue-based biomass, rice straw, wheat straw, rice husk, bagasse, cocoa shell, etc. are used.

[0031] The physical material used in the present disclosure may be a mixture of various powders derived from the above-mentioned biomass resources, as long as the particle size is 2 mm or less. It should be noted that the particle size in the present disclosure may be a value obtained by passing through a sieve or mesh with any aperture.

[0032] When the particle size exceeds 2 mm, unevenness will occur on the surface of the molded recycled natural material, which will deteriorate the appearance and cause cracks to occur during drying after molding, which is not preferable.

[0033] As at least one powder selected from the above-mentioned biomass resource sources with a particle size of less than 2 mm, there can be mentioned: sawdust of the above-mentioned waste resources and unutilized resources, wood-based biomass, food waste, agricultural residue-based biomass, wood powder obtained from end materials, waste materials, etc., powder crushed and classified by any installation, etc.

[0034] For at least one powder (including mixed powder) selected from the above-mentioned biomass resource sources with a particle size of 2 mm or less, from the perspective of further exerting the effects of the present disclosure and the load on the environment, the natural origin index (excluding water) defined in ISO 16128 is set to 0.5 or more, and more preferably 0.7 or more, thereby further reducing the load on the environment and contributing to the solution of the problem of resource depletion.

[0035] The content of the powder derived from these biomass resources is desirably 20 to 65% by mass, more preferably 30 to 65% by mass, and particularly preferably 35 to 55% by mass, relative to the total amount of the recycled natural raw materials, from the perspectives of reducing the environmental load, mainly the amount of carbon dioxide emissions, and the dimensional accuracy and strength of the recycled natural materials.

[0036] If the content is less than 20 mass %, shrinkage during drying is large, the dimensional accuracy of the recycled natural material may be poor, and the environmental load may increase. On the other hand, if it exceeds 65 mass %, the strength of the recycled natural material may be insufficient.

[0037] The cutting improving material used in the present disclosure is at least one selected from thermoplastic solids having a melting point of 40° C. or higher.

[0038] The cutting improvement material composed of a thermoplastic solid used in the present disclosure can be used without particular limitation as long as it is a wax, a fatty acid or a derivative thereof, or a thermoplastic resin having a melting point of 40° C. or higher.

[0039] Examples of waxes having a melting point of 40° C. or higher include candelilla wax, carnauba wax, rice bran wax, wood wax, jojoba oil and other plant waxes, beeswax, lanolin, spermaceti and other animal waxes, montan wax, ozokerite, ceresin and other mineral waxes, paraffin wax, microcrystalline wax / petroleum waxes and other petroleum waxes, Fischer-Tropsch wax, polyethylene wax, amide wax and other synthetic hydrocarbons, montan wax derivatives, paraffin wax derivatives, microcrystalline wax derivatives and other modified waxes, hydrogenated castor oil, hydrogenated castor oil derivatives, hydrogenated palm oil and other hydrogenated waxes, and the like.

[0040] It should be noted that carnauba wax is a wax obtained by extracting and purifying the leaves of the carnauba palm tree. Traditionally, the light yellow ones collected from young leaves have been classified as Grade 1, and the light brown ones collected from old leaves have been classified as Grade 2 (or 3).

[0041] In addition, examples of fatty acids or derivatives thereof having a melting point of 40° C. or higher include fatty acids such as myristic acid, stearic acid, and behenic acid, sodium, calcium, magnesium, and other salts of these fatty acids, i.e., fatty acid salts, stearyl stearate, glyceryl monostearate, glyceryl distearate, sorbitan monostearate, sorbitan tristearate, and fatty acid esters such as polyethylene glycol distearate, and fatty acid amides such as stearic acid amide.

[0042] Furthermore, examples of the thermoplastic resin having a melting point of 40° C. or higher include polyethylene and polypropylene.

[0043] The cutting improvement materials including these thermoplastic solids may be used alone or in combination of two or more (hereinafter referred to as "at least one"), and commercially available products may be used.

[0044] Regarding the melting point of the cutting improvement material including the thermoplastic solid used, it is desirable to preferably use a thermoplastic solid having a melting point of 60°C or more and 150°C or less, and more preferably use a wax or oil having a melting point of 75°C or more and 120°C or less, from the perspective of ease of compounding with powders derived from biomass resources and excellent strength of recycled natural materials.

[0045] As the cutting improvement material containing a thermoplastic solid that can be preferably used, carnauba wax, rice bran wax, candelilla wax, hydrogenated castor oil, glyceryl monostearate, glyceryl distearate, sorbitan monostearate, sorbitan tristearate and the like are desirable.

[0046] It should be noted that if the melting point of the thermoplastic solid such as wax or oil used is lower than 40°C, it is not preferred because it will soften due to the temperature caused by external factors such as the environment and friction when using recycled natural materials, thereby reducing the strength.

[0047] For these cutting-improving materials including a thermoplastic solid having a melting point of 40° C. or higher, the natural origin index (excluding water) defined in ISO 16128 is preferably 0.5 or higher in order to further exert the effects of the present disclosure and reduce the load on the environment.

[0048] The "natural origin index (excluding water)" in the present disclosure (including the embodiments described below) refers to the index display of ISO 16128. The natural origin index (excluding water) is set to 0.5 or more, and more preferably set to 0.8 or more, thereby extremely reducing the load on the environment and becoming able to contribute to the solution of the problem of resource depletion.

[0049] In addition, the cutting improvement material including the thermoplastic solid described above preferably has a penetration (25° C.) of 50 or less in order to further exert the effects of the present disclosure, particularly to improve strength.

[0050] The needle penetration (25°C) in the present disclosure is defined in JIS K2235 5.4, and is set to 50 or less, and more preferably 10 or less, so as to maintain the machinability and obtain a high-strength recycled natural material. From this aspect, carnauba wax, rice bran wax, candelilla wax, hydrogenated castor oil, etc. are preferably used as the cutting improvement material containing the thermoplastic solid.

[0051] The total content of these cutting improvement materials including thermoplastic solids is desirably 15 to 55% by mass, more preferably 15 to 50% by mass, and particularly preferably 15 to 40% by mass, relative to the total amount of the recycled natural raw materials, from the perspective of dimensional accuracy and machinability of the recycled natural materials.

[0052] If these contents are less than 15% by mass, shrinkage is large during drying after molding, dimensional accuracy may be reduced, and the machinability of the recycled natural material may sometimes become insufficient. On the other hand, if they exceed 55% by mass, aggregation occurs when mixed with powders of body materials and binder materials, sometimes causing uneven existence of the components, so it is not preferred.

[0053] As the binder used in the present disclosure, water-soluble or even hydrophilic ones are preferred, for example, at least one of cellulose fiber (including nanofiber), methylcellulose, carboxymethyl cellulose (CMC) or its salt, hydroxypropyl methylcellulose, sodium alginate, polyvinyl alcohol, polyethylene oxide, polyacrylamide, maleic acid copolymer resin, etc. can be used. As the salt of each of the above carboxymethyl cellulose (CMC), sodium, ammonium, etc. can be mentioned.

[0054] These binders are preferably of natural origin, and ammonium carboxymethyl cellulose (CMC) is more preferably used from the viewpoint of imparting water resistance.

[0055] For these adhesive materials, from the perspective of further exerting the effects of the present disclosure and the load on the environment, the natural origin index (excluding water) defined in ISO 16128 is preferably set to 0.5 or more, and more preferably set to 0.7 or more, thereby further reducing the load on the environment and contributing to the solution of the problem of resource depletion.

[0056] The content of these binders is preferably 10 to 50% by mass, more preferably 20 to 50% by mass, and particularly preferably 30 to 45% by mass, based on the total amount of the recycled natural raw materials.

[0057] If the content of these binders is less than 10% by mass, the moldability is poor, the shape cannot be maintained during drying, and the strength of the recycled natural material may become insufficient. On the other hand, if it exceeds 50% by mass, the recycled natural material becomes hard and the machinability may be insufficient.

[0058] The regenerated natural raw material in the present disclosure contains a base material comprising at least one powder (including a mixed powder) selected from the above-mentioned biomass resource sources having a particle size of less than 2 mm, and a cutting improvement material comprising a thermoplastic solid having a melting point of 40° C. or above. As mentioned above, the content ratio of the base material / cutting improvement material / binding material in the total amount is calculated on a mass basis (mass %) and is 20 to 65 / 15 to 55 / 10 to 50, preferably 30 to 65 / 15 to 50 / 20 to 50, and more preferably 35 to 55 / 15 to 40 / 30 to 45. In addition, from the perspective of further exerting the effects of the present disclosure and imparting water resistance, a crosslinking agent for crosslinking the aforementioned binding material may be further contained.

[0059] As the crosslinking agent for crosslinking the adhesive material, preferably one having a carboxylic acid group for ester crosslinking the adhesive material is used, and specific examples thereof include succinic acid, malic acid, maleic acid, tartaric acid, citric acid, and polyacrylic acid.

[0060] The content of these crosslinking agents is preferably 0.1 to 5% by mass, more preferably 0.5 to 2% by mass, based on the total amount of the recycled natural raw material, from the viewpoint of achieving water resistance, suppressing a decrease in strength due to moisture absorption, and suppressing discoloration of the material.

[0061] Furthermore, the regenerated natural raw material disclosed in the present invention may contain, in addition to a physical material comprising at least one powder (including a mixed powder) selected from the above-mentioned biomass resource sources having a particle size of 2 mm or less, a cutting improvement material comprising a thermoplastic solid having a melting point of 40° C. or more, a binder, and a cross-linking agent, a coloring material (dyes, inorganic pigments, organic pigments), iron oxide, zinc oxide, titanium oxide, carbon black, natural pigments, etc. for coloring the regenerated natural raw material as needed.

[0062] For these recycled natural raw materials, from the viewpoint of further exerting the effects of the present disclosure and from the viewpoint of environmental load, the natural origin index (excluding water) is preferably 0.5 or more.

[0063] By setting the natural origin index (excluding water) of the regenerated natural raw material to 0.75 or more, more preferably 0.85 or more, a regenerated natural raw material having an extremely small load on the environment can be obtained.

[0064] When the natural origin index (excluding water) of the regenerated natural raw material is set to 0.75 or more, this can be achieved by appropriately selecting the thermoplastic solid having a melting point of 40° C. or more and the binder to be of natural origin.

[0065] The regenerated natural raw material disclosed in the present invention is prepared by mixing a base material including at least one powder (including a mixed powder) selected from the above-mentioned biomass resource sources having a particle size of 2 mm or less, a cutting improvement material including a thermoplastic solid having a melting point of 40° C. or more, and a binder in the above-mentioned ratios, adding water while stirring to form a molding precursor, molding into a predetermined shape, and drying, thereby obtaining a target regenerated natural raw material such as regenerated wood, for example, using a Henschel mixer, a planetary mixer, a kneader, or the like. A physical material comprising at least one powder (including a mixed powder) selected from the above-mentioned biomass resource sources having a particle size of 2 mm or less, a cutting improvement material comprising a thermoplastic solid having a melting point of 40°C or more, and a binding material are mixed, and then water (purified water, distilled water, etc.) is added while stirring in a manner such that the moisture content becomes 40 to 80% to form a molding precursor, and then formed into a specified shape, such as a rod, plate, tube, block, or sheet, and dried, thereby producing a target regenerated natural raw material.

[0066] Furthermore, the kneaded products can be molded into a rod, round rod, plate or sheet using an extruder or the like, using a die or T-die having a predetermined diameter, and then dried to produce a molded body having a predetermined shape.

[0067] Furthermore, by appropriately combining the pressing pressure, moisture content, physical materials including various powders (wood powder, etc.) derived from biomass resources, and cutting improvement materials and adhesive materials including thermoplastic solids derived from natural sources during extrusion molding, the physical properties (including porosity) of the recycled natural raw materials can be widely controlled, thereby obtaining a recycled natural raw material that can meet the requirements in terms of texture, strength, moldability, etc.

[0068] In the present disclosure, the form and use of the above-mentioned recycled natural raw materials are not particularly limited. For example, the above-mentioned recycled natural raw materials can be formed into a rod shape and further processed to form a shaft for writing tools or pencil shafts. Furthermore, various recycled natural raw materials used in shafts for makeup tools such as eyeliners, eyebrow pencils, and eye shadows, various containers, vibration plates of audio equipment, shells, and automobile interior parts can be cited.

[0069] The regenerated natural raw material of the present disclosure thus constituted has excellent machinability without sacrificing strength and water resistance, has low environmental load, can be easily manufactured, and can contribute to solving the problem of resource depletion, such as regenerated wood, and a method for manufacturing the same.

[0070] In addition, the recycled natural raw materials are formed into rods and further processed into shaft wood for writing tools or pencil shafts. They have the same easy sharpening, drop resistance, and water resistance as existing wooden shafts, and have less environmental load. The molding machines used for molding existing pencils and writing tools (including cosmetic tools with wooden shafts) can be used without modification, thereby obtaining shaft wood for writing tools or pencil shafts that can be easily manufactured.

[0071] Example

[0072] The present disclosure will be described below based on examples and comparative examples, but the present disclosure is not limited to these examples.

[0073] (Example 1)

[0074] In a Henschel mixer, cypress wood powder with a particle size of less than 2 mm obtained from lumber mill waste as a biomass resource, an equal amount of carnauba wax No. 2 (melting point 82°C, needle penetration (25°C): less than 1, manufactured by TOYOCHEM Co., Ltd., the same below) powder as a thermoplastic solid serving as a cutting improvement material, and an equal amount of carboxymethyl cellulose (CMC) sodium (manufactured by Nippon Paper Industries, Ltd., the same below) as a binder are dry-mixed, and then purified water in an amount equal to the content is added while stirring to obtain a molding precursor.

[0075] The molded precursor is molded into After being formed into a rod with a length of 180 mm, it was dried at 50°C to obtain of stick-shaped recycled wood.

[0076] (Example 2)

[0077] The same procedures as in Example 1 were carried out except that carboxymethylcellulose ammonium (CMC ammonium) (manufactured by Nichirin Chemical Industries, Ltd., hereinafter the same) was used instead of the CMC sodium described in Example 1 and the mixture was heated at 150° C. for 1 hour after drying to obtain a Recycled wood in stick shape with a length of 180mm.

[0078] (Example 3)

[0079] The same method as in Example 1 was used except that polyvinyl alcohol (PVA) (manufactured by KURARAY CO., LTD.) was used instead of sodium CMC. Recycled wood in stick shape with a length of 180mm.

[0080] (Example 4)

[0081] The same method as in Example 2 was used except that cypress wood powder with a particle size of 1 mm or less obtained from waste materials of a lumber mill was used instead of the cypress wood powder described in Example 2 as a biomass resource to obtain Recycled wood in stick shape with a length of 180mm.

[0082] (Example 5)

[0083] The same method as in Example 4 was carried out except that half of the amount of CMC ammonium described in Example 4 was replaced with cellulose fiber (CF) (manufactured by Nippon Paper Industries, Ltd.) to obtain Recycled wood in stick shape with a length of 180mm.

[0084] (Example 6)

[0085] The same method as in Example 2 was used except that cedar wood powder with a particle size of 0.6 mm or less obtained from thinned wood was used as the biomass resource instead of the cypress wood powder described in Example 2. Recycled wood in stick shape with a length of 180mm.

[0086] (Example 7)

[0087] The same method as in Example 2 was used except that fir wood powder with a particle size of 0.3 mm or less obtained from thinned wood was used as the biomass resource instead of the cypress wood powder described in Example 2. Recycled wood in stick shape with a length of 180mm.

[0088] (Example 8)

[0089] The same method as in Example 7 was used except that the amount of carnauba wax No. 2 described in Example 7 was two-thirds of the amount of wood powder to obtain Recycled wood in stick shape with a length of 180mm.

[0090] (Example 9)

[0091] The same method as in Example 7 was used except that the amount of carnauba wax No. 2 described in Example 7 was half the amount of wood powder to obtain Recycled wood in stick shape with a length of 180mm.

[0092] (Example 10)

[0093] The same method as in Example 7 was used except that the amount of carnauba wax No. 2 described in Example 7 was one-third and four times the amount of wood powder to obtain Recycled wood in stick shape with a length of 180mm.

[0094] (Example 11)

[0095] The same method as in Example 7 was used except that the amount of CMC ammonium described in Example 7 was changed to one-third and four times the amount of wood powder to obtain Recycled wood in stick shape with a length of 180mm.

[0096] (Example 12)

[0097] The same method as in Example 7 was used except that the amount of CMC ammonium described in Example 7 was changed to two-thirds of the amount of wood powder to obtain Recycled wood in stick shape with a length of 180mm.

[0098] (Example 13)

[0099] The same method as in Example 7 was used except that the amount of carnauba wax No. 2 described in Example 7 was one-third of the amount of wood powder and the amount of ammonium CMC was two-thirds of the amount of wood powder to obtain Recycled wood in stick shape with a length of 180mm.

[0100] (Example 14)

[0101] The same method as in Example 2 was used except that bamboo powder with a particle size of 0.1 mm or less obtained from unused trees was used instead of the cypress powder described in Example 2 as the biomass resource to obtain Recycled wood in stick shape with a length of 180mm.

[0102] (Example 15)

[0103] The same method as in Example 14 was used except that the amount of carnauba wax No. 2 described in Example 14 was halved to obtain Recycled wood in stick shape with a length of 180mm.

[0104] (Example 16)

[0105] The same method as in Example 2 was used except that cocoa shell powder having a particle size of 0.6 mm or less obtained from agricultural residues was used as the biomass resource instead of the cypress wood powder described in Example 2. Recycled wood in stick shape with a length of 180mm.

[0106] (Example 17)

[0107] The same method as in Example 4 was used except that rice bran wax (melting point 79° C., needle penetration (25° C.): 5, manufactured by Boso Oil and Fat Co., Ltd.) was used instead of carnauba wax No. 2 described in Example 4 to obtain Recycled wood in stick shape with a length of 180mm.

[0108] (Example 18)

[0109] The same method as in Example 4 was used except that Fischer-Tropsch wax (melting point 113° C., needle penetration (25° C.): 1, manufactured by Nippon Seiro Co., Ltd.) was used instead of the carnauba wax No. 2 described in Example 4 to obtain Recycled wood in stick shape with a length of 180mm.

[0110] (Example 19)

[0111] The same procedures as in Example 4 were carried out except that glyceryl mono / distearate (melting point 63° C., needle penetration (25° C.): 20, manufactured by RIKEN VITAMIN CO., LTD.) was used instead of carnauba wax No. 2 described in Example 4 to obtain Recycled wood in stick shape with a length of 180mm.

[0112] (Example 20)

[0113] The same procedures as in Example 4 were carried out except that sorbitan tristearate (melting point 54° C., needle penetration (25° C.): 5, manufactured by Kao Corporation) was used instead of the carnauba wax No. 2 described in Example 4 to obtain Recycled wood in stick shape with a length of 180mm.

[0114] (Example 21)

[0115] The same procedures as in Example 4 were carried out except that stearic acid amide (melting point 102° C., needle penetration (25° C.): 12, manufactured by Mitsubishi Chemical Corporation) was used instead of the carnauba wax No. 2 described in Example 4 to obtain Recycled wood in stick shape with a length of 180mm.

[0116] (Example 22)

[0117] The same procedures as in Example 4 were carried out except that stearic acid (melting point 66° C., needle penetration (25° C.): 18, manufactured by NOF Corporation) was used instead of the carnauba wax No. 2 described in Example 4 to obtain Recycled wood in stick shape with a length of 180mm.

[0118] (Example 23)

[0119] The same procedures as in Example 4 were carried out except that high-density polyethylene (melting point 126° C., needle penetration (25° C.): less than 1, manufactured by Japan Polyethylene Co., Ltd.) was used instead of carnauba wax No. 2 described in Example 4 to obtain Recycled wood in stick shape with a length of 180mm.

[0120] (Comparative Example 1)

[0121] In a Henschel mixer, the same cypress wood powder with a particle size of less than 1 mm as in Example 4 and the same amount of CMC sodium as in Example 1 are added, dry mixed, and then purified water in an amount equal to the content is added while stirring to obtain a molded precursor.

[0122] The molded precursor is molded into After being dried at 50°C, Recycled wood in stick shape with a length of 180mm.

[0123] (Comparative Example 2)

[0124] The same method as in Example 2 was used except that CMC ammonium was used instead of CMC sodium in Comparative Example 1 and the mixture was heated at 150° C. for 1 hour after drying to obtain Recycled wood in stick shape with a length of 180mm.

[0125] (Comparative Example 3)

[0126] The same method as in Comparative Example 2 was used except that half the amount of CMC ammonium was used for the wood powder to obtain Recycled wood in stick shape with a length of 180mm.

[0127] (Comparative Example 4)

[0128] The same method as in Comparative Example 3 was used except that a quarter of the amount of CMC ammonium was used for the wood powder to obtain Recycled wood in stick shape with a length of 180mm.

[0129] For each of the stick-shaped regenerated wood materials of Examples 1 to 23 and Comparative Examples 1 to 4 obtained above, the natural origin index was calculated as follows, and the breakage strength, machinability, and water resistance were evaluated by the following measurement methods.

[0130] These evaluation results are shown in Table 1. Table 2 shows the blending ratios of the physical materials, cutting improvement materials, and adhesive materials used in Examples 1 to 23 and Comparative Examples 1 to 4 (16.7%, 33.3%, and 66.7% in Table 2 represent 1 / 6, 1 / 3, and 2 / 3, respectively), and the natural origin index.

[0131] (Natural Origin Index)

[0132] The natural origin index (excluding water) of each of the stick-shaped wood and the like obtained in Examples 1 to 23 and Comparative Examples 1 to 4 was obtained by calculating the composition ratio as a percentage using the weight ratio of the raw materials mixed in the stick-shaped wood and the water-free weight of the natural raw materials and the natural origin part of the natural origin raw materials defined in ISO 16128. The higher the value, the higher the ratio of animal and plant-derived materials and the less the amount of petroleum-derived materials used, which can indicate that the load on the environment is small.

[0133] (Evaluation method of breakage strength)

[0134] A load was applied in a 90° direction at a position 80 mm away from a position where each obtained stick-shaped wood or the like was fixed, and the maximum load when broken was measured to evaluate the breaking strength (N).

[0135] (Evaluation method of cutting torque)

[0136] For each obtained stick-shaped wood, etc., the tip was adjusted to a diameter of 2 mm using a pencil sharpener, and then the pencil sharpener set on a fixed jig connected to a rotation torque measuring device was used to mechanically rotate the opposite side of the pencil sharpener to cut until the wood was sharp. The peak value (N·mm) of the rotation torque during this period was measured as an evaluation of the cutting torque.

[0137] (Machinability Determination)

[0138] From the above-mentioned results of the breakage strength and cutting torque, the balance between strength and machinability required during cutting is determined based on the following indexes.

[0139] Evaluation indicators:

[0140] Good: The breaking strength is 12N or more and the cutting torque is less than 100N·mm

[0141] Hard: Cutting torque is 100N·mm or more

[0142] Weak: Breakage strength is less than 12N

[0143] (Evaluation method of water resistance)

[0144] Each of the obtained stick-shaped wood and the like was immersed in water, and the presence or absence of water resistance was evaluated based on whether the shape was maintained after 24 hours.

[0145] [Table 1]

[0146]

[0147] [Table 2]

[0148]

[0149] When examining the evaluation results of Tables 1 and 2 above, it was confirmed that the embodiments within the scope of the present disclosure maintained a high natural origin index compared to the comparative examples, and highly combined high breakage strength and low cutting torque, and had excellent machinability. In addition, when a cellulose derivative (CMC ammonium) was used as a binder, sufficient water resistance could be exerted.

[0150] Industrial Applicability

[0151] Recycled natural materials such as recycled wood are obtained that have excellent machinability without sacrificing strength and water resistance, have low environmental load, can be easily manufactured, and contribute to solving the problem of resource depletion. If the rod-shaped recycled natural materials are further processed, pencil shafts (including colored pencil leads), shafts (shaft bodies) for writing tools, and shafts (shaft bodies) for cosmetics such as eyeliners, eyebrow pencils, eye shadows, etc. in stick form can be obtained.

Claims

1. A regenerated natural raw material, characterized in that The invention at least comprises: a physical material including at least one kind of powder of biomass resource origin with a particle size of 2 mm or less; a cutting improvement material including a thermoplastic solid with a melting point of 40° C. or more; and, a binding material, wherein the regenerated natural raw material is composed of a mass ratio of a physical material / a cutting improvement material / a binding material = 20 to 65 / 15 to 55 / 10 to 50, and is molded into a prescribed shape.

2. The regenerated natural raw material according to claim 1, characterized in that The cutting improving material has a natural origin index defined in ISO 16128 of 50% or more.

3. The regenerated natural raw material according to claim 1 or 2, characterized in that The binder material is cellulose or a cellulose derivative.

4. The regenerated natural raw material according to claim 3, characterized in that The cellulose derivative is ammonium carboxymethyl cellulose.

5. A rod-shaped regenerated natural raw material, characterized in that: The regenerated natural raw material according to claim 1 or 2 is formed into a rod shape.

6. A shaft wood for a writing tool or pencil shaft, characterized in that: The rod-shaped regenerated natural raw material of claim 5 is further processed.

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