JP2013221149A - Method for producing lignin decomposed product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a lignin decomposed product, capable of producing a high-molecular-weight and linear lignin decomposed product with less modification.SOLUTION: A method for producing a lignin decomposed product has the following steps (1) and (2). Step (1): A lignocellulose raw material is heat-treated in an organic solvent including one or two or more reacting agents selected from the group consisting of (A) a nitrogen atom-containing basic compound, (B) a metal alkoxide; (C) a fluoride of an element belonging to group 1 or 2 of the periodic table; (D) a vanadium atom-containing heteropoly acid or a salt thereof; (E) an aryl borane; (F) a halide of gallium, indium or thallium; and (G) a lanthanoid salt of trifluoromethane sulfonic acid to thereby obtain a solution including the lignin decomposed product; and step (2): the lignin decomposed product is separated from the heat-treated solution.

Description

  The present invention relates to a method for producing a lignin degradation product.

Lignin is an aromatic polymer contained in many plants including trees and gramineous plants, and is contained in plants together with cellulose and hemicellulose. Since these three components exist as lignocellulose in a complexly bound form in the plant cell wall, it is not easy to separate them. In addition, lignin has a higher reactivity than cellulose and easily undergoes a condensation reaction by heating, so that it becomes an inactive mass substance having poor solvent solubility.
As a method for separating lignin from a lignocellulose raw material in a high yield, a kraft cooking method mainly used in a paper company or the like is generally known (for example, see Patent Document 1). Moreover, the process using hydrochloric acid as an acid is known (for example, refer nonpatent literature 1).

JP 2004-190150 A

Journal of Applied Polymer Science, 2008, 1158-1168.

  However, lignin is subject to significant chemical modification by heating in a mixed solution of sodium hydroxide or sodium sulfite in kraft cooking and hydrochloric acid treatment. For this reason, it is difficult to extract lignin present in plants without denaturation, and it is difficult to find a wide range of lignin utilization targets from the viewpoint of biomass utilization. Further, it is difficult to further modify and functionalize the polymer aromatic polymer.

  Accordingly, the present invention provides a method for producing a lignin degradation product, which can easily produce a low-modified, high-molecular-weight and linear lignin degradation product that is easily modified and functionalized as a high-molecular aromatic polymer. It is an issue to provide.

The present inventors have found that the above problems can be solved by heat-treating the lignocellulose raw material in an organic solvent containing a specific reactant, and have completed the present invention.
That is, this invention relates to the manufacturing method (henceforth "the manufacturing method of this invention") of a lignin degradation product which has the following process (1) and process (2).
Step (1): The lignocellulose raw material is heat-treated in an organic solvent containing one or more reactants selected from the group consisting of the following (A) to (G), and a solution containing a lignin decomposition product is obtained. Step of obtaining (A) Basic compound containing nitrogen atom (B) Metal alkoxide (C) Fluoride of element belonging to group 1 or 2 of periodic table (D) Heteropoly acid containing vanadium atom or salt thereof E) Arylborane (F) Halide of gallium, indium or thallium (G) Lanthanoid salt of trifluoromethanesulfonic acid Step (2): Step of separating lignin decomposition product from the solution

  According to the production method of the present invention, a low-modified and high-molecular-weight linear lignin degradation product can be produced from a lignocellulose raw material. Moreover, since the lignin degradation product obtained by the production method of the present invention is a low-modified linear polymer, it can be easily modified and functionalized as a high molecular weight aromatic polymer. The chemical modification and derivatization according to the purpose of use and conversion to can be advantageously performed.

[Method for producing lignin degradation product]
The manufacturing method of the lignin degradation product of this invention has the following process (1) and process (2), It is characterized by the above-mentioned.
Step (1): The lignocellulose raw material is heat-treated in an organic solvent containing one or more reactants selected from the group consisting of the following (A) to (G), and a solution containing a lignin decomposition product is obtained. Step of obtaining (A) Basic compound containing nitrogen atom (B) Metal alkoxide (C) Fluoride of element belonging to group 1 or 2 of periodic table (D) Heteropoly acid containing vanadium atom or salt thereof E) Arylborane (F) Halide of gallium, indium or thallium (G) Lanthanoid salt step of trifluoromethanesulfonic acid step (2): Step of separating lignin degradation product from the above solution In the present invention, “lignin degradation product” The term “lignin” means a lignin having a solvent solubility, which is separated from a lignocellulose raw material and solubilized to such an extent that it can be dissolved in an organic solvent.
The reason why a low-denature, high-molecular-weight and linear lignin degradation product is obtained by the production method of the present invention is not clear, but by using the specific reactant, it is contained in a large amount in the lignin structure. Can decompose lignin without excessively cleaving the β-O-4 bond, which is an indicator of the linearity (linearity) of the lignin structure, and suppresses reactions that cause insolubilization such as condensation. Therefore, it is presumed that a low-modified, high-molecular-weight and linear lignin degradation product can be obtained.

  Here, the “β-O-4 bond” in lignin or lignin degradation product is a bond connecting the β-position carbon of the side chain represented by the following formula (1) and the oxygen atom of the phenolic hydroxyl group. is there. The β-O-4 bond has been previously reported as a major bond in lignin in many literatures (eg, J. Agric. Food Chem., 2004, 52, 1850-1860, J. Agric. Food). Chem., 2008, 56, 9525-9534).

  The β-O-4 bond amount in the lignin decomposition product refers to the number of β-O-4 bonds present in the lignin decomposition product per unit mass. The β-O-4 bond amount is an index for evaluating the linearity (linearity) of the lignin degradation product, and is specifically measured by the method described in Examples.

(Process (1))
In the method for producing a lignin degradation product of the present invention, a lignocellulose raw material is heat-treated in an organic solvent containing one or more reactants selected from the group consisting of (A) to (G). A step of obtaining a solution containing a decomposition product (hereinafter simply referred to as “step (1)”).

<Lignocellulose raw material>
In the production method of the present invention, the lignocellulose raw material refers to plant-based biomass containing cellulose, hemicellulose, and lignin.
Lignocellulose raw materials include various kinds of wood such as wood chips obtained from conifers such as larch and cedar, hardwood such as oil palm and cypress; wood pulp produced from wood, cotton linter pulp obtained from fibers around cotton seeds Pulps such as bagasse (sugar cane squeezed), rice straw, corn stalks and leaves, empty fruit bunches (hereinafter referred to as “EFB”), etc .; Plant shells such as shells and coconut shells; papers such as newspapers, cardboard, magazines and fine papers; These lignocellulose raw materials may be used alone or in combination of two or more.

  Of these, wood, paper, plant stems / leaves / fruits, plant shells and algae are preferred from the viewpoint of yield improvement of lignin degradation products, availability, and raw material costs, coniferous chips, hardwood chips, One or more selected from the group consisting of bagasse, rice straw, corn stalks / leaves, EFB, rice husk, palm husk, coconut husk, paper and algae are more preferred, obtained from the trunk of bagasse, EFB, oil palm Wood chips are more preferred, and bagasse is even more preferred.

  From the viewpoint of improving the yield of lignin degradation product, the lignocellulose raw material preferably has a lignin content of 5% by mass or more, more preferably 10% by mass or more, and still more preferably 15% by mass or more. It is. The lignin content can be measured by the method described in Examples described later.

<Pretreatment process>
The production method of the present invention has a step of pretreating the lignocellulose raw material (hereinafter referred to as “pretreatment step”) before the step (1) from the viewpoint of improving the yield of lignin degradation products and suppressing the modification of lignin. It is preferable. Preferable pretreatment methods include one or more pretreatments selected from the group consisting of pulverization treatment, hydrothermal treatment and enzyme treatment. A more preferred pretreatment is a grinding treatment and / or an enzyme treatment.

[Crushing treatment]
By crushing the lignocellulose raw material, the lignocellulose raw material is reduced in size and the crystal structure of cellulose contained in the lignocellulose raw material is destroyed, so that the lignin separation / decomposition efficiency can be improved.
When pulverization is performed, the amount of water in the lignocellulose raw material is 40% by mass or less based on the dry weight of the lignocellulose raw material from the viewpoint of improving the pulverization efficiency of the lignocellulose raw material and the yield of the lignin decomposition product. Is preferred. In addition, since it is difficult to make the water content in a lignocellulose raw material into 0 mass%, it is preferable that this water content is 0.01-40 mass% with respect to the dry weight of a lignocellulose raw material, More preferably Is 0.1 to 35% by mass, more preferably 1 to 30% by mass, and still more preferably 1 to 20% by mass.
The amount of water in the lignocellulose raw material can be measured using a commercially available infrared moisture meter or the like, and specifically can be measured by the method described in the examples.

  When the amount of water in the lignocellulose raw material used for the pulverization treatment exceeds 40% by mass, the lignocellulose raw material is dried by a known method (hereinafter, also referred to as “drying treatment”), and the water content. It is preferable to adjust the amount to be 40% by mass or less based on the dry weight of the lignocellulose raw material. Examples of the drying method include hot air heat receiving drying method, conductive heat receiving drying method, dehumidifying air drying method, cold air drying method, microwave drying method, infrared drying method, sun drying method, vacuum drying method, freeze drying method and the like. It is done. As the dryer used for the drying treatment, a known one can be appropriately selected and used. The drying process can be either a batch process or a continuous process.

The pulverization treatment can be performed using a known pulverizer. There is no restriction | limiting in particular in the grinder used, What is necessary is just to be able to make a lignocellulose raw material small particle.
Specific examples of the pulverizer include a high pressure compression roll mill, a roll mill such as a roll rotating mill, a vertical roller mill such as a ring roller mill, a roller race mill or a ball race mill, a rolling ball mill, a vibration ball mill, a vibration rod mill, and a vibration tube. Container driven media mills such as mills, planetary ball mills or centrifugal fluidization mills, tower crushers, stirring tank mills, medium stirring mills such as flow tank mills or annular mills, high-speed centrifugal roller mills, ong mills, etc. Consolidation shear mill, mortar, stone mortar, mass collider, fret mill, edge runner mill, knife mill, pin mill, cutter mill and the like. Among these, from the viewpoint of pulverization efficiency and productivity of the lignocellulose raw material, a container-driven medium mill or a medium stirring mill is preferable, a container-driven medium mill is more preferable, a vibrating ball mill, a vibrating rod mill, or a vibrating tube mill. A vibration mill such as a vibration ball mill or a vibration rod mill is more preferable.

  The pulverization method may be either batch type or continuous type. The material of the apparatus and / or medium used for pulverization is not particularly limited, and examples thereof include iron, stainless steel, alumina, zirconia, silicon carbide, silicon nitride, and glass, but efficiently destroy the crystal structure of cellulose. Therefore, iron, stainless steel, zirconia, silicon carbide, and silicon nitride are preferable, and iron or stainless steel is preferable from the viewpoint of industrial use.

  When the apparatus to be used is a vibration mill and the medium is a rod, the outer diameter of the rod is preferably in the range of 0.1 to 100 mm, more preferably in the range of 0.5 to 50 mm, from the viewpoint of grinding efficiency of the lignocellulose raw material. It is. When the size of the rod is in the above range, the lignocellulose raw material can be made into small particles efficiently. The rod filling rate varies depending on the type of vibration mill, but is preferably 10 to 97%, more preferably 15 to 95%, still more preferably 20 to 80%, and still more preferably 25 to 70%. . When the filling rate is within this range, the contact frequency between the lignocellulose raw material and the rod is improved, and the pulverization efficiency of the lignocellulose raw material can be improved without disturbing the movement of the medium. Here, the filling rate refers to the apparent volume of the medium relative to the volume of the stirring section of the vibration mill.

  When the apparatus to be used is a vibration mill and the medium is a ball, the outer diameter of the ball is preferably in the range of 0.1 to 100 mm, more preferably in the range of 0.5 to 50 mm, from the viewpoint of grinding efficiency of the lignocellulose raw material. It is. When the size of the balls is in the above range, the lignocellulose raw material can be efficiently made into small particles. The filling rate of the balls is preferably 10 to 97%, more preferably 15 to 75%, and still more preferably 20 to 50%. When the filling rate is within this range, the contact frequency between the lignocellulose raw material and the ball is improved, and the pulverization efficiency of the lignocellulose raw material can be improved without disturbing the movement of the medium.

  Although there is no limitation in particular in the temperature at the time of a grinding | pulverization process, -100-200 degreeC is preferable from a viewpoint of operation cost, the deterioration suppression of a lignocellulose raw material, and the modification | denaturation suppression of a lignin, 0-150 degreeC is more preferable, 5-100 More preferred is ° C.

  The pulverization time may be appropriately adjusted so that the pulverized lignocellulose raw material is reduced in size. Although it varies depending on the pulverizer to be used and the amount of energy to be used, it is usually 1 minute to 48 hours. ˜30 hours is more preferred.

  The average particle size of the lignocellulose raw material obtained after the pulverization treatment is preferably 1 to 150 μm, more preferably 5 to 100 μm, from the viewpoint of improving the yield of the lignin degradation product. In addition, the average particle diameter of the lignocellulose raw material obtained after a grinding | pulverization process is measured by the method as described in an Example.

[Hydrothermal treatment]
Hydrothermal treatment is a treatment in which high-temperature water or a buffer solution acts on a lignocellulose raw material under pressurized conditions. Hydrothermal treatment can be performed using a known reaction apparatus, and the reaction apparatus used is not particularly limited. In the hydrothermal treatment, it is preferable to use the lignocellulose raw material in a slurry state. The content of the lignocellulose raw material in the slurry is preferably 1 to 500 g / L, more preferably 1 to 200 g / L, still more preferably 5 to 150 g / L, and still more preferably 8 to 100 g from the viewpoint of improving fluidity. / L. Examples of the slurry include water and various buffer solutions.

  Hydrothermal treatment is preferably performed under acidic conditions from the viewpoint of improving the production efficiency and yield of the lignin degradation product. The pH of the slurry is preferably pH 3-7, more preferably pH 4-6, from the viewpoints of production efficiency and yield improvement of lignin degradation products, and suppression of lignin denaturation. The pH of the slurry can be appropriately adjusted by using an inorganic acid such as hydrochloric acid, sulfuric acid or phosphoric acid, or an organic acid such as acetic acid or citric acid.

The conditions for the hydrothermal treatment are preferably a temperature of 100 to 400 ° C. and a pressure of 0.1 to 4 MPa, and more preferably a temperature of 140 to 200 ° C. and a pressure of 0.5 to 1 MPa. The treatment time is preferably from 0.1 to 3 hours. The hydrothermal treatment method may be either batch type or continuous type.
The lignocellulose raw material after hydrothermal treatment may be in a wet state or may be obtained by further drying treatment, but from the viewpoint of improving the yield of lignin degradation product, a wet state is preferable.

[Enzyme treatment]
The enzyme treatment is a treatment for causing an enzyme to act on the lignocellulose raw material. Examples of the enzyme used for the enzyme treatment include cellulase and hemicellulase, and these can be used alone or in combination of two or more.

Specific examples of the cellulase include cellulase preparations derived from Trichoderma Reesei such as Cellcrust 1.5L (trade name, manufactured by Novozymes), CellicCTec2 (trade name, manufactured by Novozymes ), and Bacillus sp. Cellulase derived from KSM-N145 (FERM P-19727), or Bacillus sp. KSM-N252 (FERM P-17474), Bacillus sp. KSM-N115 (FERM P-19726), Bacillus Cellulases derived from various strains such as SP ( Bacillus sp.) KSM-N440 (FERM P-19728), Bacillus sp. KSM-N659 (FERM P-19730), and Trichoderma viride ( Trichoderma viride ), Aspergillus Akureatasu (Aspergillus acleatus), Clostridium thermocellum (Clostridium thermocellum), Clostridium Suterukorari Um (Clostridium stercorarium), Clostridium josui (Clostridium josui) Cellulomonas Fimi (Cellulomonas fimi), Acremonium cell Lori caustics (Acremonium celluloriticus), Irupekkusu Rakuteusu (Irpex lacteus), Aspergillus niger (Aspergillus niger), Humicola insolens (Humicola insolens) from And a thermostable cellulase derived from Pyrococcus horikoshii .
Among these, from the viewpoint of improving the production efficiency and yield of lignin degradation products, cellulases derived from Trichoderma Reesei , Trichoderma viride or Humicola insolens , such as cell crust 1 .5L (Novozymes, trade name), TP-60 (Meiji Seika Co., Ltd., trade name), CellicCTec2 (Novozymes, trade name), Accelerase DUET (Genencore, trade name), or Ultraflo L (Trade name, manufactured by Novozymes).

Specific examples of β-glucosidase, which is a kind of cellulase, include enzymes derived from Aspergillus niger (for example, Novozyme 188 (trade name, manufactured by Novozymes) and β-glucosidase (produced by Megazyme)), Examples include enzymes derived from Trichoderma Reesei and Penicillium emersonii .

Specific examples of hemicellulase include a hemicellulase preparation derived from Trichoderma Reesei such as CellicHTec2 (manufactured by Novozymes, trade name) and a Bacillus sp. KSM-N546 (FERM P-19729) Aspergillus niger , Aspergillus niger , Trichoderma viride , Humicola insolens , Bacillus alcalophilus xylanase, Thermomyces (Aureobasidium), Streptomyces (Streptomyces), Clostridium (Clostridium), Thermotoga (Thermotoga), Thermoascus (Thermoascus), Karudoseramu (Caldocellum), thermo mono Supora (Thermomonospora) of the genus from Shiranaze and the like.

  The enzyme used is preferably at least one selected from the group consisting of cellulase and hemicellulase from the viewpoint of production efficiency and yield improvement of lignin degradation products, and cellobiohydrolase, β-glucosidase, endoglucanase. And at least one selected from the group consisting of hemicellulase, and more preferably at least one selected from the group consisting of cellobiohydrolase and endoglucanase.

The treatment conditions for the enzyme treatment of the lignocellulose raw material can be appropriately selected depending on the lignin content in the lignocellulose raw material, the cellulose I-type crystallinity, and the type of enzyme used.
For example, when the enzyme is used and a lignocellulose raw material is used as a substrate, the enzyme is added in an amount of 0.001 to 15% (v / v) with respect to a substrate suspension of 0.5 to 20% (w / v). The saccharification treatment can be performed by reacting in a buffer solution having a pH of 2 to 10 at a reaction temperature of 10 to 90 ° C. and a reaction time of 30 minutes to 5 days.
The pH of the buffer is preferably selected as appropriate according to the type of enzyme used, preferably pH 3-7, more preferably pH 4-6.
Moreover, it is preferable to select the said reaction temperature suitably according to the kind of enzyme to be used, Preferably it is 20-70 degreeC, More preferably, it is 40-60 degreeC.
Furthermore, the reaction time is preferably appropriately selected according to the type of enzyme used, preferably 0.5 to 3 days, more preferably 0.5 to 2 days.

<Reactant>
In the production method of the present invention, 1 is selected from the group consisting of the following (A) to (G) from the viewpoint of obtaining a low-modified and linear polymer lignin degradation product and improving the yield of the lignin degradation product. A seed or two or more reactants are used.
(A) Basic compound containing nitrogen atom (B) Metal alkoxide (C) Fluoride of an element belonging to Group 1 or Group 2 of the periodic table (D) Heteropolyacid or salt thereof containing vanadium atom (E) Arylborane (F) Halide of gallium, indium or thallium (G) Lanthanoid salt of trifluoromethanesulfonic acid From the viewpoint of obtaining a low-modified and linear polymer lignin degradation product, and from the viewpoint of improving the yield of lignin degradation product 1 type or 2 or more types of reagents chosen from the group which consists of said (A)-(D), (F) and (G) are preferable, More preferably, said (A)-(D) and (G 1 type or 2 or more types of reactants selected from the group consisting of), more preferably 1 type or 2 or more types of reactants selected from the group consisting of the above (A) to (C) and (G). .

[(A) Basic compound containing nitrogen atom]
In the production method of the present invention, (A) a nitrogen atom-containing basic compound that is suitably used as a reactant includes aliphatic monoamines, aliphatic diamines, aromatic monoamines, aromatic diamines, and guanidines. From the viewpoint of obtaining a linear polymer lignin degradation product with low denaturation, from the viewpoint of improving the yield of the lignin degradation product, more preferably one or two or more kinds of reactants selected from the group consisting of amidines. Preferably, one or more reactants selected from the group consisting of aliphatic diamines, aromatic diamines and amidines, more preferably one type selected from the group consisting of aliphatic diamines and amidines. Or two or more reactants.
Examples of the component (A) include aliphatic monoamines such as monomethylamine, dimethylamine, trimethylamine, diethylmethylamine, ethyldimethylamine, triethylamine, diethylisopropylamine, tributylamine, and piperidine. For example, ethylenediamine, putrescine, cadaverine, hexamethylenediamine, imidazoline, 2-methylimidazoline, imidazolidine, etc., and aromatic monoamines include, for example, pyridine, picoline, 2,6-lutidine, aniline, etc. Examples include N, N-dimethyl-4-aminopyridine, bipyridine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, and imidazole. Examples thereof include gin, tetramethylguanidine, nitroguanidine, phenylguanidine, 1,3-diphenylguanidine, 1,5,7-triazabicyclo [4.4.0] dece-5ene, and amidines include, for example, 1 , 8-diazabicyclo [5.4.0] undec-7-ene, 1,5-diazabicyclo [4.3.0] non-5-ene, and the like.
Among them, from the viewpoint of obtaining a low-modified, high-molecular-weight and linear lignin degradation product, and from the viewpoint of improving the yield of lignin degradation product, it is selected from the group consisting of aliphatic diamines, aromatic diamines, and amidines. As one or more kinds of reactants, ethylenediamine, hexamethylenediamine, N, N-dimethyl-4-aminopyridine, 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,5- One or more selected from the group consisting of diazabicyclo [4.3.0] non-5-ene, imidazoline and 2-methyl-imidazoline are preferred, and ethylenediamine and N, N-dimethyl-4-amino are more preferred. The group consisting of pyridine, 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,5-diazabicyclo [4.3.0] non-5-ene. Al is one or more reactants selected.

[(B) metal alkoxide]
In the production method of the present invention, examples of the (B) metal alkoxide suitably used as the reactant include C1-C5 alkali metal alkoxides.
For example, lithium methoxide, lithium ethoxide, lithium n-propoxide, lithium isopropoxide, lithium n-butoxide, lithium isobutoxide, lithium tert-butoxide, lithium n-pentoxide, lithium isopentoxide, sodium methoxide, sodium Ethoxide, sodium n-propoxide, sodium isopropoxide, sodium n-butoxide, sodium isobutoxide, sodium tert-butoxide, sodium n-pentoxide, sodium isopentoxide, potassium methoxide, potassium ethoxide, potassium n-propoxy Potassium isopropoxide, potassium n-butoxide, potassium isobutoxide, potassium tert-butoxide, potassium n-pentoxide, Rium isopentoxide, rubidium methoxide, rubidium ethoxide, rubidium n-propoxide, rubidium isopropoxide, rubidium n-butoxide, rubidium isobutoxide, rubidium n-pentoxide, rubidium isopentoxide, cesium methoxide, cesium ethoxide Cesium n-propoxide, cesium isopropoxide, cesium n-butoxide, cesium isobutoxide, cesium tert-butoxide, cesium n-pentoxide, cesium isopentoxide and the like.
Among these, from the viewpoint of obtaining a low-modified, high-molecular-weight and linear lignin degradation product and improving the yield of the lignin degradation product, lithium methoxide, lithium ethoxide, lithium tert-butoxide, lithium isopentoxide, Sodium methoxide, sodium ethoxide, sodium tert-butoxide, sodium isopentoxide, potassium methoxide, potassium ethoxide, potassium tert-butoxide, potassium isopentoxide, cesium methoxide, cesium ethoxide, cesium tert-butoxide, and One or more selected from the group consisting of cesium isopentoxide is preferred, more preferably lithium methoxide, lithium ethoxide, lithium tert-butoxide, sodium methoxide, sodium ether. One or more selected from the group consisting of xoxide, sodium tert-butoxide, potassium methoxide, potassium ethoxide, potassium tert-butoxide, cesium methoxide, cesium ethoxide, and cesium tert-butoxide, more preferably Consists of lithium methoxide, lithium ethoxide, lithium tert-butoxide, sodium methoxide, sodium ethoxide, sodium tert-butoxide, potassium methoxide, potassium ethoxide, potassium tert-butoxide, cesium methoxide, and cesium ethoxide One or more selected from the group, more preferably sodium methoxide, sodium ethoxide, sodium tert-butoxide, potassium methoxide, potassium One or more selected from the group consisting of toxide, potassium tert-butoxide, and cesium methoxide, more preferably sodium methoxide, sodium ethoxide, sodium tert-butoxide, potassium methoxide, potassium ethoxide, And one or more selected from the group consisting of potassium tert-butoxide.

[(C) Fluoride of an element belonging to Group 1 or Group 2 of the periodic table}
In the production method of the present invention, the (C) fluoride suitably used as a reactant includes lithium fluoride, sodium fluoride, potassium fluoride, rubidium fluoride, cesium fluoride, francium fluoride, magnesium fluoride. , Calcium fluoride, strontium fluoride, and barium fluoride. Of these, lithium fluoride, sodium fluoride, potassium fluoride, rubidium fluoride, fluoride, from the viewpoint of obtaining a low-modified polymer and linear lignin degradation product and improving the yield of the lignin degradation product. One or more selected from the group consisting of cesium, magnesium fluoride, calcium fluoride, strontium fluoride, and barium fluoride are preferable, and lithium fluoride, sodium fluoride, potassium fluoride, fluoride are more preferable. One or more selected from the group consisting of rubidium, cesium fluoride, magnesium fluoride, calcium fluoride, and barium fluoride, more preferably lithium fluoride, sodium fluoride, potassium fluoride, cesium fluoride, Selected from the group consisting of magnesium fluoride, calcium fluoride, and barium fluoride Species or two or more, more preferably one or more selected from the group consisting of lithium fluoride, sodium fluoride, potassium fluoride, cesium fluoride, magnesium fluoride, and calcium fluoride, more preferably fluorine. 1 type, or 2 or more types selected from the group consisting of lithium fluoride, sodium fluoride, potassium fluoride, and cesium fluoride.

[(D) Heteropolyacid containing vanadium atom or salt thereof]
In the production method of the present invention, the (D) heteropolyacid or a salt thereof suitably used as a reactant contains a vanadium atom, and specific examples thereof include phosphomolybdovanadic acid and phosphomolybdo tungsten. Vanadic acid, phosphotungstovanadic acid, lithium phosphomolybdovanadate, phosphomolybdotungstovanadate, lintonguestovanadate lithium, phosphomolybdovanadate sodium, phosphomolybdotongostanadate sodium, phosphotungstovanadate sodium, Potassium phosphomolybdovanadate, potassium phosphomolybdotangtovanadate, potassium phosphotungstovanadate, rubidium phosphomolybdovanadate, rubidium phosphomolybdostandovanadate, rubidium phosphotungstovanadate Cesium, phosphomolybdovanadate cesium, phosphomolybdo-tungstovanadate cesium, lintongue stanbosanodate cesium, phosphomolybdovanadate magnesium, phosphomolybdo-tungstovanadate magnesium, phosphotungstovanadate magnesium, phosphomolybdovanadate calcium , Phosphorus molybdo-tungstovanadate, calcium lintonguestovanadate, strontium phosphomolybdovanadate, strontium phosphomolybdostande vanadate, strontium lintongostobanadate, barium phosphomolybdovanadate, barium phosphomolybdotangostovanadate And lintonguest vanadate vanadate, calcium vanadate apatite, and the like. Among them, from the viewpoint of obtaining a low-modified, high-molecular-weight and linear lignin degradation product, and from the viewpoint of improving the yield of lignin degradation product, phosphomolybdovanadic acid, phosphomolybdotungstovanadic acid, lintongtovanadic acid, phosphorus Lithium molybdovanadate, lithium molybdotungstovanadate, lithium tungstostobanadate, sodium molybdovanadonate, molybdo sodium tungstate vanadate, sodium lintongostavanadate, potassium molybdovanadonate, phosphoromolyb Potassium dotangostovanadate, potassium phosphotungstovanadate, cesium phosphomolybdovanadate, cesium phosphomolybdostandovanadate, cesium phosphotungstovanadate, magnesium phosphomolybdovanadate, phosphomolybdo Magnesium budtungstovanadate, Magnesium phosphotungstovanadate, Calcium phosphomolybdovanadate, Calcium phosphomolybdostandovanadate, Calcium phosphotungstovanadate, Barium phosphomolybdovanadate, Barium phosphomolybdostandovanadate, Lintan One or two or more selected from the group consisting of barium gustobanadate and calcium apatite vanadate are preferred, and more preferably, phosphomolybdovanadic acid, phosphomolybdotungtovanadic acid, lintongostobanaic acid, phosphomolybdo Sodium vanadate, Phosphorus molybdo-tungstovanadate, Phosphorus-tungstovanadate sodium, Phosphorus molybdovanadate potassium, Phosphorus molybdo-tungstovanadate , Potassium phosphotungstovanadate, magnesium phosphomolybdovanadate, magnesium phosphomolybdostando vanadate, magnesium lintongostobanadate, calcium phosphomolybdovanadate, calcium phosphomolybdostandovanadate, calcium phosphotungstovanadate, One or more selected from the group consisting of barium phosphomolybdovanadate, barium phosphomolybdotungstovanadate, barium lintongostobanadate, and calcium apatate, more preferably phosphomolybdovanadate, phosphomolyb Dotangost vanadic acid, lintongost vanadic acid, sodium phosphomolybdovanadate, phosphomolybdostando sodium vanadate, sodium lintongost vanadate, The group consisting of potassium phosphomolybdovanadate, potassium phosphomolybdotangtovanadate, potassium phosphotungstovanadate, calcium phosphomolybdovanadate, calcium phosphomolybdotangtovanadate, calcium lintongostavanadate, and calcium avanadate apatite One or more selected from the group consisting of sodium phosphomolybdovanadate, sodium phosphomolybdotungstovanadate, sodium lintongostobanadate, potassium phosphomolybdovanadate, potassium phosphomolybdovandate, lintan Gustovanadate potassium, phosphomolybdovanadate calcium, phosphomolybdotonguest vanadate calcium, lintongostobanadate calcium, and calcium vanadate It is one or more selected from the group consisting of beam apatite.

[(E) arylborane]
In the production method of the present invention, the (E) aryl borane suitably used as a reactant may be a borane compound having one or more aryl groups, and a part or all of the hydrogen atoms on the aromatic ring are halogenated. An arylborane compound substituted with a substituent containing an atom or a halogen atom is preferred, and an arylborane compound in which part or all of the hydrogen atoms on the aromatic ring are substituted with a fluorine atom is more preferred.
Specific examples thereof include tris (pentafluorophenyl) borane, 3,5-bis (trifluoromethyl) phenyl boric acid, and 3,4,5-trifluorophenyl boric acid. Of these, tris (pentafluorophenyl) borane is preferable from the viewpoint of obtaining a low-modified, high-molecular-weight and linear lignin degradation product and improving the yield of the lignin degradation product.

[(F) Halide of gallium, indium or thallium]
In the production method of the present invention, examples of the (F) halide suitably used as a reactant include fluoride, chloride, bromide and iodide of gallium, indium or thallium.
Among these, from the viewpoint of obtaining a low-modified and high-molecular-weight linear lignin degradation product and improving the yield of the lignin degradation product, preferably a group consisting of fluoride, chloride, bromide and iodide of gallium or indium One or more selected from the group consisting of gallium chloride, gallium bromide, indium fluoride, indium chloride, indium bromide, and indium iodide. is there.

[(G) Lanthanide salt of trifluoromethanesulfonic acid]
In the production method of the present invention, the lanthanoid salt of (G) trifluoromethanesulfonic acid that is preferably used as a reactant includes lanthanum trifluoromethanesulfonate, cerium trifluoromethanesulfonate, praseodymium trifluoromethanesulfonate, and trifluoromethanesulfonic acid. Neodymium, promethium trifluoromethanesulfonate, samarium trifluoromethanesulfonate, europium trifluoromethanesulfonate, gadolinium trifluoromethanesulfonate, terbium trifluoromethanesulfonate, dysprosius trifluoromethanesulfonate, holmium trifluoromethanesulfonate, erbium trifluoromethanesulfonate, Thulium trifluoromethanesulfonate, trifluoromethanesulfuric acid Phosphate ytterbium trifluoromethanesulfonate lutetium like.
Among them, from the viewpoint of obtaining a low-modified and high-molecular-weight linear lignin degradation product and improving the yield of the lignin degradation product, lanthanum trifluoromethanesulfonate, cerium trifluoromethanesulfonate, neodymium trifluoromethanesulfonate, trifluoromethane. One or more selected from the group consisting of samarium methanesulfonate, europium trifluoromethanesulfonate, gadolinium trifluoromethanesulfonate, ytterbium trifluoromethanesulfonate, and lutetium trifluoromethanesulfonate, more preferably trifluoromethane Lanthanum sulfonate, cerium trifluoromethanesulfonate, neodymium trifluoromethanesulfonate, samarium trifluoromethanesulfonate, trifluorometa One or more selected from the group consisting of gadolinium sulfonate and ytterbium trifluoromethanesulfonate, more preferably lanthanum trifluoromethanesulfonate, cerium trifluoromethanesulfonate, samarium trifluoromethanesulfonate, and ytterbium trifluoromethanesulfonate 1 type, or 2 or more types selected from the group consisting of, more preferably 1 type or 2 types or more selected from the group consisting of lanthanum trifluoromethanesulfonate, cerium trifluoromethanesulfonate, and ytterbium trifluoromethanesulfonate.

The use amount of the reactant selected from the group consisting of (A) to (C) and (E) to (G) is as follows: a low-denatured, high-molecular-weight and linear lignin degradation product, and lignin From the viewpoint of improving the yield of the decomposed product, it is preferably 0.01 to 200 mol%, more preferably 0.1 to 200 mol%, still more preferably 0.1 to 150 mol% with respect to the amount of the lignocellulose raw material. 1.0 to 150 mol% is even more preferable.
Moreover, the usage-amount of the reactive agent chosen from the group which consists of (A)-(C) and (E)-(G) is 0.1-300 mol% with respect to the amount of lignin substances in a lignocellulose raw material. Preferably, 0.5-200 mol% is more preferable, and 1.0-150 mol% is still more preferable.
The mol% of the reactant is a value obtained by converting the amount of the lignocellulose raw material and the amount of the lignin substance as follows. That is, cellulose, hemicellulose and lignin contained in the lignocellulose raw material are regarded as glucose obtained by subtracting the molecular weight of one molecule of water, xylose obtained by subtracting the molecular weight of one molecule of water, and coniferyl alcohol. The amount of these substances contained in the lignocellulose raw material is calculated as the amount of the material of the lignocellulose raw material (hereinafter also referred to as “converted material amount”). Moreover, let the said lignin substance amount contained in a lignocellulose raw material be a lignin conversion substance amount.
The contents of cellulose, hemicellulose and lignin contained in the lignocellulose raw material, and the converted substance amount and lignin converted substance amount of the lignocellulose raw material are specifically determined by the methods described in the examples.

In addition, the amount of the reactant (D) used is a reduced substance amount of the lignocellulose raw material from the viewpoint of obtaining a low-denature, high-molecular-weight and linear lignin degradation product and improving the yield of the lignin degradation product. 0.01-200 mg / mmol is preferable, 0.1-100 mg / mmol is more preferable, 1.0-75 mg / mmol is still more preferable, and 1.0-50 mg / mmol is still more preferable.
Moreover, 0.05-300 mg / mmol is preferable with respect to the said lignin conversion substance amount, 0.5-200 mg / mmol is more preferable, 1.0-150 mg / mmol is still more preferable.

<Organic solvent>
In step (1), the lignocellulose raw material is heat-treated in an organic solvent containing the reactant. The organic solvent to be used is not particularly limited as long as the obtained lignin decomposition product can be dissolved, and includes, for example, hydrocarbons, alcohols, nitriles, ethers, amides, sulfoxides and ketones. The 1 type (s) or 2 or more types chosen from a group can be mentioned.

Examples of the hydrocarbons include pentane, hexane, heptane, octane, nonane, decane, benzene, toluene, xylene, and the alcohols include methanol, ethanol, diethylene glycol, n-propanol, isopropyl alcohol, n- Examples include butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, and the like.
Examples of the nitriles include acetonitrile and propiononitrile. Examples of the ethers include dimethyl ether, ethyl methyl ether, diethyl ether, tetrahydrofuran, tetrahydropyran, dioxane and the like, and examples of the amides include dimethylformamide and dimethylacetamide. Examples of the sulfoxides include dimethyl sulfoxide and the like, and examples of the ketones include acetone and methyl ethyl ketone. These organic solvents can be used alone or in combination of two or more.

  Among these organic solvents, from the viewpoint of improving the extraction efficiency of lignin degradation products, selected from the group consisting of benzene, toluene, methanol, ethanol, isopropyl alcohol, acetonitrile, tetrahydrofuran, dioxane, dimethylformamide, dimethyl sulfoxide, acetone and methyl ethyl ketone. One or more selected from the group consisting of methanol, ethanol, isopropyl alcohol, acetonitrile, dioxane, dimethylformamide, dimethyl sulfoxide, and acetone are more preferable, and ethanol, isopropyl alcohol, acetonitrile , One or more selected from the group consisting of dioxane, dimethyl sulfoxide, and acetone, more preferably isopropyl alcohol Acetonitrile, dioxane, dimethyl sulfoxide, and one selected from the group consisting of acetone or two or more and further preferably more.

  The amount of the organic solvent used in the step (1) is preferably 2 to 40 times the dry weight of the lignocellulose raw material from the viewpoint of improving the production efficiency of the lignin degradation product and enhancing the degradability of the lignin, More preferably, it is 2-30 mass times, More preferably, it is 3-30 mass times, More preferably, it is 5-30 mass times.

<Heat treatment>
The heat treatment temperature in the step (1) is preferably 30 to 300 ° C., more preferably 50 to 280 ° C., and still more preferably 70 to 250 ° C., from the viewpoint of suppressing lignin denaturation and improving the yield of lignin degradation products. More preferably, it is 90-200 degreeC, More preferably, it is 90-180 degreeC. The heating device used is preferably an autoclave or a microwave heating device, and more preferably a microwave heating device, from the viewpoint of suppressing lignin denaturation and improving the yield of lignin degradation products.

  The pressure during the heat treatment is preferably from 0.01 to 30 MPa, more preferably from 0.03 to 20 MPa, and even more preferably from 0.05 to 15 MPa, from the viewpoints of inhibiting denaturation of lignin and improving the yield of lignin degradation products. More preferably, it is 0.07 to 13 MPa.

The heat treatment time is appropriately selected according to the processing amount of the lignocellulose raw material, but is preferably 1 minute to 5 hours, more preferably 1 minute to 5 minutes from the viewpoint of suppressing lignin denaturation and improving the yield of lignin degradation products. It is 3 hours, more preferably 2 minutes to 2 hours, more preferably 5 minutes to 2 hours, still more preferably 10 minutes to 2 hours.
By the above method, a solution containing a lignin degradation product is obtained in step (1).

(Process (2))
The production method of the present invention includes a step of separating a lignin degradation product from the solution obtained in the above step (1) (hereinafter simply referred to as “step (2)”).
Although the method of isolate | separating a lignin degradation product is not specifically limited, For example, filtration, centrifugation, etc. are mentioned. After removing the insoluble solid from the solution, the organic solvent is distilled off from the liquid containing the lignin decomposition product, and the remaining dry solid is washed and dried to obtain an extract containing the lignin decomposition product. it can. From the viewpoint of increasing the purity of the lignin decomposition product separated by removing water-soluble polysaccharides and the like, it is preferable to wash the dried product after distilling off the organic solvent with water.
Here, the solid obtained by washing the insoluble solid with water again and drying at 105 ° C. for 12 hours is referred to as “the final residue obtained in step (2)”.
Moreover, when an acid or a base is used as the reactant in the step (1), it is preferable to perform a neutralization step in the step (2) from the viewpoint of suppressing denaturation of the lignin degradation product. These steps can be performed by a conventional method.

[Lignin degradation product]
The lignin degradation product obtained by the production method of the present invention preferably has a weight average molecular weight in the range of 1,000 to 1,000,000 from the viewpoint of physical properties as a polymer such as solvent solubility and heat resistance. More preferably, it is 2,000-500,000, More preferably, it is 2,000-300,000, More preferably, it is 2,000-200,000, More preferably, it is 2,000-100,000. In addition, the weight average molecular weight of a lignin degradation product is measured by the method as described in an Example.

  In addition, the lignin degradation product obtained by the production method of the present invention has a β-O-4 bond amount of 100 μmol or more per 1 g of the lignin degradation product from the viewpoint of physical properties as a polymer such as solvent solubility and heat resistance. It is preferable that it is 100 μmol to 10 mmol, more preferably 150 μmol to 7.5 mmol, still more preferably 200 μmol to 5.5 mmol. The β-O-4 bond amount is an index for evaluating the linearity (linearity) of the lignin degradation product as described above, and is specifically measured by the method described in the examples.

  The lignin degradation product obtained by the production method of the present invention is a low-denature, high-molecular-weight, linear lignin, and has solvent solubility. For this reason, it can utilize advantageously as a conversion material to low molecular weight aromatic compounds, such as vanillin, syringaldehyde, parahydroxybenzaldehyde, vanillic acid, syringic acid, and 4-hydroxybenzoic acid. The lignin degradation product can be used as an antibacterial agent, agricultural chemical, thermosetting resin, cement dispersant, storage battery dispersant, additive for cosmetics, and other functional materials.

  In the following Examples and Comparative Examples, “%” means “% by mass” unless otherwise specified. Moreover, the measuring method and evaluation method of various physical properties are as follows.

(1) Method for measuring average particle size of pulverized product of lignocellulose raw material The average particle size of the pulverized product of lignocellulose raw material is measured by using a laser diffraction / scattering particle size distribution measuring device “LA-950” (manufactured by Horiba, Ltd.). And measured. The measurement conditions were ultrasonic treatment for 1 minute before particle size measurement, water was used as a dispersion medium during measurement, and the volume-based median diameter was measured at room temperature.

(2) Measurement of water content of lignocellulose raw material An infrared moisture meter (product name “FD-610”, manufactured by Kett Scientific Laboratory Co., Ltd.) was used to measure the water content of the lignocellulose raw material. The measurement was performed at 150 ° C., and the point at which the rate of change in weight for 30 seconds was 0.1% or less was taken as the end point of the measurement. The value of the measured water content was converted to mass% with respect to the dry weight of the lignocellulose raw material.

(3) Calculation of lignin content in lignocellulose raw material The lignin content in the lignocellulose raw material was calculated by the following formula. In addition, the measuring method of lignin content is the same also about the final residue obtained at the process (2) of this invention.
Lignin content (g) = [acid-insoluble lignin content (%) + acid-soluble lignin content (%)] × sampled amount (dry basis) (g) / 100
Here, the acid-insoluble lignin content and the acid-soluble lignin content were calculated by the following methods.

(Calculation of acid-insoluble lignin content)
The lignocellulose raw material pulverized by the pulverization process described later was dried at 105 ° C. for 1 day. 500 mg of this dried sample was placed in a vial, 8 mL of 72% sulfuric acid was added, and the mixture was allowed to stand at room temperature for 3 hours, and stirred with a glass rod as appropriate. Thereafter, 300 mL of water was added, transferred to an Erlenmeyer flask, and treated at 120 ° C. for 1 hour using an autoclave. Thereafter, the sample was subjected to suction filtration using a glass filter ("GA-100" manufactured by ADVANTEC) whose constant weight was measured in advance. Wash the residue thoroughly with 90 ° C hot water and store the filtrate (A). Wash the glass filter with the residue thoroughly with 90 ° C hot water, then dry at 105 ° C and measure the constant weight. The amount of crude acid insoluble lignin collected (dry basis) was determined.
Crude acid insoluble lignin content (%) = [dry weight of lignin residue (g) / sampled amount (dry basis) (g)] × 100

The acid-insoluble lignin content was calculated by subtracting the ash content in the crude acid-insoluble lignin according to the following formula.
Acid-insoluble lignin content (%) = crude acid-insoluble lignin content (%) × [100−ash content (%)] / 100

(Calculation of acid-soluble lignin content)
The crude acid-insoluble lignin was transferred to a crucible where the constant weight was measured in advance, held at 600 ° C. for 24 hours, and then cooled, the constant weight of the crucible was measured, and after ashing, the dry weight of the sample was determined. It was.
Ash content (%) = [Dry weight after ashing (g) / Amount of crude acid insoluble lignin collected (dry basis) (g)] × 100

The acid-soluble lignin content was calculated by the following method.
The filtrate (A) was made up to a volume of 400 mL, the absorbance at 205 nm was measured using a UV-Vis absorptiometer, and the acid-soluble lignin content was determined from the following formula. At this time, the filtrate (A) was appropriately diluted with 3% sulfuric acid and measured so that the absorbance was 0.3 to 0.8.
Acid-soluble lignin content (%) = d × v × (As−Ab) / (a × w) × 100
d: dilution rate, v: filtrate constant volume (L), As: absorbance of sample solution, Ab: absorbance of blank solution, a: extinction coefficient of lignin, w: sample collection amount (dry basis) (g)
Here, the extinction coefficient (a) of lignin is 110 (L / g / cm), which is a value described as an average value reported in a reference material (“Lignin Chemical Research Method”, published by Uni Publishing Co., Ltd.). Was used.

(4) Method of measuring yield of lignin degradation product The yield of lignin degradation product was calculated from the following formula.
Yield (% by mass) of lignin degradation product = 100-[(dry weight (g) of the final residue obtained in step (2) × content of lignin (%) of the final residue obtained in step (2))] / (Lignocellulose raw material charged dry weight (g) × lignin content in lignocellulose raw material (%)) × 100

(5) Measuring method of weight average molecular weight of lignin degradation product The molecular weight of the lignin degradation product manufactured by the method as described in an Example and a comparative example was measured on the following conditions by the gel chromatography method.
Ltd. Shimadzu LC Solution System (CBM-20A / LC-20AD / SPD-M20A / CTO-20A / DGU-20A 3), connected by Showa Denko KK Column "OHpak SB803HQ" one and guard column did. N, N-dimethylformamide to which 50 mmol / L LiBr was added as an eluent was flowed at a flow rate of 0.5 mL per minute, and the column was stabilized in a constant temperature bath at 40 ° C. Measurement was performed by injecting 10 μL of the sample solution. The molecular weight of the sample was calculated based on a calibration curve prepared in advance. The calibration curve at this time includes several types of monodisperse polystyrene [manufactured by Chemco (molecular weight: 9.0 × 10 ⁴ ), Aldrich (molecular weight: 3.266 × 10 ⁴ , molecular weight: 1.37 × 10 ⁴ , 2. 43 × 10 ³ , 1.0610 ² )] as a standard sample was used.

(6) Method for measuring β-O-4 binding amount of lignin degradation product Agric. Food Chem. , (1997), 45, 2590-2592, and measured according to the following method according to the DFRC method (Derivative Flowed by Reductive Cleavage method).

After performing step (2), 50 mg of a sample (lignin degradation product) obtained by purification and freeze-drying was weighed. This sample was treated with 20 vol. The solution was added to 6.5 mL of% acetylacetic acid solution and stirred at 50 ° C. for 3.5 hours. After the solvent was distilled off under reduced pressure, the dried solid was dissolved in 5.0 mL of the solvent prepared in (dioxane / acetic acid / pure water) = (5/4/1), and 77 mg of zinc powder was added at room temperature for 30. The mixture was stirred for a minute to obtain a processed product.
Insoluble matter was removed by filtration, and the obtained filtrate was separated into 15 mL of dichloromethane and 10 mL of saturated aqueous ammonium chloride solution to which hydrochloric acid was added, and then extracted three times with dichloromethane. Was distilled off.
To the resulting oily substance, 1.5 mL each of pyridine and acetic anhydride was added and stirred at room temperature for 6 hours. Then, it distilled off under reduced pressure, the remaining oily substance was dissolved in 0.5 mL of dichloromethane, tetracosane was added as an internal standard substance, and it was used for GC-MS.

The analysis conditions of GC-MS are as follows.
Column; DB-5MS (manufactured by Shimadzu Corporation)
Sample volume: 1.0 μL
Helium flow rate; 10 mL / min vaporization chamber temperature; 280 ° C
Split ratio: 10: 1
The temperature was maintained at 100 ° C. for 1 minute, then heated to 100 to 240 ° C. at 3 ° C./minute, held at 240 ° C. for 1 minute, then heated to 240 to 300 ° C. at 30 ° C./minute, 300 Hold at 10 ° C. for 10 minutes.
The amount of β-O-4 binding of the lignin degradation product was determined using a diacetate form obtained by acetylating the hydroxyl group of coniferyl alcohol, creating a calibration curve with the peak area with respect to the concentration, paracoumaryl alcohol diacetate, and coniferyl. The amount of each diacetate substance such as alcohol diacetate and cinapyl alcohol diacetate was estimated. The amount of the three diacetate substances was added to obtain the diacetate yield. The diacetate yield (μmol / g) per unit weight was calculated by dividing the diacetate yield by the lignin weight in the degradation product sample, and this was defined as the β-O-4 bond amount of the lignin degradation product. In addition, it has shown that the lignin decomposition product with high linearity (linearity) was obtained, so that (beta) -O-4 bond amount is high.

(7) Method for measuring cellulose and hemicellulose content in lignocellulose raw material The pulverized lignocellulose raw material was subjected to Soxhlet extraction with an ethanol-dichloroethane mixed solvent (volume ratio 1/2) for 6 hours, and the sample after extraction was subjected to 60 ° C. And vacuum dried. To 2.5 g of the obtained sample, 150 mL of water, 1.0 g of sodium chlorite and 0.2 mL of acetic acid were added and heated at 70 to 80 ° C. for 1 hour. Subsequently, the operation of adding sodium chlorite and acetic acid and heating was repeated 4 times until the sample was decolorized white. The obtained white residue was filtered through a glass filter, washed with cold water and acetone, dried at 105 ° C. until a constant weight was measured, the primary residue weight was measured, and the holocellulose content was calculated according to the following formula.
Holocellulose content (mass%) = [dry weight of primary residue (g) / collected amount of lignocellulose raw material (g: dry raw material conversion)] × 100
Next, 1.0 g of the obtained primary residue was added to 25 mL of 17.5% NaOH aqueous solution and allowed to stand at room temperature for 3 minutes. Then, it was lightly crushed with a glass rod for 5 minutes, added with 17.5% NaOH aqueous solution, then covered with a watch glass for 30 minutes and allowed to stand at room temperature. Thereafter, 25 mL of distilled water at 20 ° C. was added and stirred for 1 minute, and the treated product was filtered with a glass filter and washed with distilled water until the filtrate became neutral. The filtration residue was further washed with 40 mL of 10% aqueous acetic acid, followed by 300 mL boiling water. The residue was dried at 105 ° C. until a constant weight was obtained, and this was used as a secondary residue, the dry weight was measured, and the cellulose content was calculated from the following formula.
Cellulose content (mass%) = [secondary residue dry weight (g) / amount of lignocellulose raw material collected (g: in terms of dry raw material)] × 100

Moreover, hemicellulose content was computed by the following formula.
Hemicellulose content (mass%) = the holocellulose content (mass%) − the cellulose content (mass%)

(8) Cellulose-converted substance amount, calculation method of hemicellulose-converted substance amount Bagasse used as a lignocellulose raw material (sugarcane pomace, moisture content 7.2%) is the cellulose content determined by the measuring method of (7) Was 37% by mass and the hemicellulose content was 34% by mass, and 0.37 g of cellulose and 0.34 g of hemicellulose per 1.0 g of the lignocellulose raw material.
The cellulose weight was divided by 162 obtained by subtracting the molecular weight of one molecule of water from the molecular weight of glucose, and the amount of cellulose equivalent substance per 1.0 g of the lignocellulose raw material was calculated. Further, the hemicellulose weight per 1.0 g of the lignocellulose raw material was calculated by dividing the hemicellulose weight by 132 obtained by subtracting the molecular weight of one molecule of water from the xylose molecular weight.

(9) Lignocellulose raw material equivalent substance amount and calculation method of lignin equivalent substance amount Bagasse (sugar cane pomace, water content 7.2%) used as the lignocellulose raw material contains lignin in the (3) lignocellulose raw material. The lignin content calculated | required by the measuring method of quantity was 23 mass%, and the lignin content per 1.0g of lignocellulose raw materials was 0.23g. Here, the amount of lignin-converted substance per 1.0 g of the lignocellulose raw material was calculated by dividing the weight of lignin by the molecular weight 180 of coniferyl alcohol. In addition, (7) cellulose and hemicellulose content in the lignocellulose raw material, and (8) cellulose and hemicellulose equivalents obtained from the cellulose and hemicellulose equivalents and lignin equivalents. The total amount was taken as the amount of lignocellulose raw material equivalent.

<Example 1>
(Pretreatment process)
As a lignocellulose raw material, bagasse (sugarcane pomace, moisture content 7.2%) is put in a vacuum dryer and dried at 105 ° C. for 12 hours, moisture content 2.0 mass%, lignin content 23 mass%. Of dry bagasse was obtained.
100 g of the obtained dry bagasse powder was put into a vibrating ball mill (ball outer diameter: 12 mm, filling rate: 30%) and pulverized at room temperature for 24 hours to obtain a crushed bagasse powder (average particle size of 58.3 μm). ).

[Step (1)]
Dry bagasse powder (absolute dry weight 1.0 g) is taken in a reaction vessel (volume 25 mL), dimethyl sulfoxide 22.0 g, 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU) (sum) 187 mg (manufactured by Kojun Pharmaceutical Co., Ltd.) was added and sealed, and then a microwave heating device (“Initiator 60” manufactured by Biotage Japan Co., Ltd.) was stirred at 900 rpm for 90 minutes at a temperature of 130 ° C. and a pressure of 0.1 MPa. Was subjected to microwave heating to obtain a solution containing a lignin degradation product.

[Step (2)]
The solution obtained in the step (1) was neutralized by adding a saturated aqueous solution of ammonium chloride, followed by filtration to separate the insoluble solid and the filtrate. The insoluble solid was washed with dimethyl sulfoxide, water, and a mixed solvent of dimethyl sulfoxide / water until the washed liquid became transparent. After collecting the filtrate and washing liquid and distilling off the solvent under reduced pressure, the obtained extract was 364 mg (of which (3) lignin calculated by the method for calculating lignin content in the lignocellulose raw material) The degradation product content was 134 mg). The insoluble solid was again washed with water and dried at 105 ° C. for 12 hours to obtain 800 mg of the final residue. The results are shown in Table 1.

<Example 2>
The same operation as in Example 1 was carried out except that 124 mg of triethylamine (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of 1,8-diazabicyclo [5.4.0] undec-7-ene. The obtained extract was 234 mg, of which lignin degradation product was 123 mg. In addition, 976 mg of the final residue was obtained. The results are shown in Table 1.

<Example 3>
The same operation as in Example 1 was performed except that 66.4 mg of sodium methoxide (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of 1,8-diazabicyclo [5.4.0] undec-7-ene. went. The obtained extract was 478 mg, of which lignin degradation product was 183 mg. In addition, 644 mg of the final residue was obtained. The results are shown in Table 1.

<Example 4>
The same operation as in Example 1 was carried out except that 137 mg of potassium tert-butoxide was used instead of 1,8-diazabicyclo [5.4.0] undec-7-ene. The obtained extract was 482 mg, of which lignin degradation product was 143 mg. In addition, 739 mg of the final residue was obtained. The results are shown in Table 1.

<Example 5>
The same operation as in Example 1 except that 60.0 mg of calcium vanadate apatite (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of 1,8-diazabicyclo [5.4.0] undec-7-ene. Went. The obtained extract was 384 mg, of which lignin degradation product was 104 mg. Moreover, 980 mg of final residues were obtained. The results are shown in Table 1.

<Example 6>
The same operation as in Example 1 was performed except that 71.3 mg of potassium fluoride was used instead of 1,8-diazabicyclo [5.4.0] undec-7-ene. The obtained extract was 305 mg, of which lignin degradation product was 117 mg. In addition, 921 mg of the final residue was obtained. The results are shown in Table 1.

<Example 7>
628 mg of tris (pentafluorophenyl) boron (manufactured by Wako Pure Chemical Industries, Ltd.) was used in place of 1,8-diazabicyclo [5.4.0] undec-7-ene, and hydrogen carbonate in step (2) The same operation as in Example 1 was performed except that neutralization with sodium was performed. The obtained extract was 688 mg, of which 89 mg of lignin degradation product. In addition, 959 mg of the final residue was obtained. The results are shown in Table 1.

<Example 8>
Same as Example 1 except that 275 mg of indium chloride was used in place of 1,8-diazabicyclo [5.4.0] undec-7-ene and that it was neutralized with sodium bicarbonate in step (2). Was performed. The obtained extract was 448 mg, of which lignin degradation product was 92 mg. Moreover, 873 mg of final residues were obtained. The results are shown in Table 1.

<Example 9>
Example except that 760 mg of ytterbium trifluoromethanesulfonate was used in place of 1,8-diazabicyclo [5.4.0] undec-7-ene and that it was neutralized with sodium bicarbonate in step (2). The same operation as 1 was performed. The obtained extract was 1050 mg, of which lignin degradation product was 129 mg. Moreover, 936 mg of final residues were obtained. The results are shown in Table 1.

<Comparative Example 1>
The same operation as in Example 1 was performed except that 1,8-diazabicyclo [5.4.0] undec-7-ene was not used and neutralization in step (2) was not performed. The obtained extract was 175 mg, of which lignin degradation product was 81 mg. Moreover, 878 mg of final residues were obtained. The results are shown in Table 1.

<Comparative example 2>
In place of 1,8-diazabicyclo [5.4.0] undec-7-ene, 1.2 mL of hydrochloric acid (concentration: 1.0 M) (manufactured by Wako Pure Chemical Industries, Ltd.) was used, and in step (2) The same operation as in Example 1 was performed except that neutralization with sodium bicarbonate was performed. The obtained extract was 793 mg, of which lignin degradation product was 226 mg. In addition, 334 mg of the final residue was obtained. The results are shown in Table 1.

<Comparative Example 3>
158 mg of aluminum chloride (manufactured by Wako Pure Chemical Industries, Ltd.) was used in place of 1,8-diazabicyclo [5.4.0] undec-7-ene and neutralized with sodium bicarbonate in step (2) Except that, the same operation as in Example 1 was performed. The obtained extract was 417 mg, of which lignin degradation product was 105 mg. In addition, 839 mg of the final residue was obtained. The results are shown in Table 1.

<Comparative example 4>
Instead of 1,8-diazabicyclo [5.4.0] undec-7-ene, 299 mg of neodymium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) was used, and neutralized with sodium hydrogen carbonate in step (2). Except that, the same operation as in Example 1 was performed. The obtained extract was 401 mg, of which lignin degradation product was 110 mg. Further, 1062 mg of the final residue was obtained. The results are shown in Table 1.

<Comparative Example 5>
The same operation as in Example 1 was carried out except that 49.2 mg of sodium hydroxide (Wako Pure Chemical Industries, Ltd.) was used instead of 1,8-diazabicyclo [5.4.0] undec-7-ene. went. The obtained extract was 259 mg, of which lignin degradation product was 125 mg. In addition, 808 mg of the final residue was obtained. The results are shown in Table 1.

<Comparative Example 6>
With reference to the method described in Research Report of Faculty of Agriculture, Gifu University, 1988, (53), 291-299, a lignin degradation product was produced by the following method. Dry bagasse powder (absolute dry weight 1.0 g) that had been pretreated in the same manner as in Example 1 was placed in a reaction vessel (volume 25 mL), 20 g of pure water, sodium hydroxide (Wako Pure Chemical Industries, Ltd.) 49.2 mg, and 10 mg of anthraquinone as a transpiration aid and 150 mg of sodium sulfite were added and sealed, then the microwave heating apparatus (Biotage) was stirred at 900 rpm for 15 minutes at a temperature of 170 ° C. and a pressure of 0.1 MPa. -Microwave heating was performed using “Initiator 60” manufactured by Japan Co., Ltd. to obtain a solution containing a lignin degradation product. Step (2) was carried out in the same manner as in Example 1 using the above solution. The obtained extract was 756 mg, of which lignin degradation product was 214 mg. In addition, 265 mg of the final residue was obtained. The results are shown in Table 1.

  As shown in Table 1, in Examples 1 to 9, lignin degradation products having a larger amount of β-O-4 bonds than Comparative Examples 1 to 6 were obtained, and the lignin degradation products had a high weight average molecular weight. It was. This shows that according to the production method of the present invention, a low-denature and high-molecular-weight linear lignin degradation product can be obtained.

  According to the production method of the present invention, a low-modified, high-molecular-weight and linear lignin degradation product can be obtained from a lignocellulose raw material. This lignin degradation product is suitably used in the fields of agriculture, cosmetic applications, functional resins, cement dispersants, batteries, etc., as a high molecular weight aromatic polymer and as a raw material for conversion to a low molecular weight aromatic compound. be able to.

Claims (5)

The manufacturing method of a lignin decomposition product which has the following process (1) and process (2).
Step (1): The lignocellulose raw material is heat-treated in an organic solvent containing one or more reactants selected from the group consisting of the following (A) to (G), and a solution containing a lignin decomposition product is obtained. Step of obtaining (A) Basic compound containing nitrogen atom (B) Metal alkoxide (C) Fluoride of element belonging to group 1 or 2 of periodic table (D) Heteropoly acid containing vanadium atom or salt thereof E) Arylborane (F) Halide of gallium, indium or thallium (G) Lanthanoid salt of trifluoromethanesulfonic acid Step (2): Step of separating lignin decomposition product from the solution   The method for producing a lignin degradation product according to claim 1, wherein the organic solvent is one or more selected from the group consisting of isopropyl alcohol, acetonitrile, dioxane, dimethyl sulfoxide, and acetone.   The process according to claim 1 or 2, further comprising a pretreatment step in which the lignocellulose raw material is treated with one or more selected from the group consisting of pulverization treatment, hydrothermal treatment, and enzyme treatment before step (1). A method for producing a lignin degradation product.   The lignocellulose raw material is one or more selected from the group consisting of softwood chips, hardwood chips, bagasse, rice straw, corn stalks / leaves, palm empty fruit bunches, rice husks, palm shells, coconut shells, papers and algae The manufacturing method of the lignin degradation product in any one of Claims 1-3 which are these.   The weight average molecular weight obtained by the production method according to any one of claims 1 to 4 is in the range of 1,000 to 1,000,000, and the β-O-4 bond amount per gram is 100 µmol or more. There is a lignin degradation product.