JPWO2018047928A1 - Method for producing heat resistant lignin - Google Patents

Abstract

A step of mixing a raw material lignin solution with at least one solvent (a) selected from water having a volume of 1 to 50 times that of the raw material lignin solution and a hydrocarbon having a dipole moment of 0.25 d or less A process for producing heat resistant lignin, including I).

Description

  The present invention relates to thermostable lignin.

  With the recent increase in environmental awareness, biomass-derived materials are attracting attention. For example, although it is particularly remarkable in the production of bioethanol, it is often used as a biomass-derived material such as starch or sugar, which is a material that competes with food. Therefore, problems such as rising food prices and decreasing food production have been pointed out. Therefore, at present, techniques for producing raw materials from cellulosic biomass that do not compete with food are attracting attention.

Examples of cellulosic biomass that does not compete with food include palm palm trunks and pockets, palm palm fibers and seeds, bagasse (sugarcane (including high biomass amounts of sugarcane) millet), rice straw, straw, corn cob · Stem and leaf / corn residue (corn stover, corn cob, corn hull), sorghum (including sweet sorghum) residue, Jatropha seed coat and shell, cashew shell, wood chips, switchgrass, Erianthus etc. may be mentioned.
These cellulosic biomasses contain 20 to 30% by mass of lignin in addition to cellulose and hemicellulose. For example, in the papermaking process, lignin is separated from cellulose and hemicellulose, recovered as black liquor, and mainly used as fuel. However, it is desirable to extract lignin because decomposition of lignin can produce phenol derivatives and conversion to chemicals and bioplastics can be expected.

However, when using lignin as industrial materials, such as resin materials, such as a chemical, it has the problem of being inferior to physical-property values, such as heat resistance.
Patent Document 1 discloses a lignin derivative obtained by decomposing biomass by subjecting biomass to a stirring process under high temperature and high pressure in the presence of a solvent. After the above decomposition treatment, the water insoluble matter is extracted with acetone, and the acetone is distilled off to obtain a lignin derivative.
Patent Document 2 discloses a lignin-based polymer including a 1,1-diphenylpropane unit grafted with a phenol derivative at the α-position of a phenylpropane unit of lignin and having an ester site in which one or more hydroxyl groups are acylated. Do. Since lignophenol derivatives are recovered as an assembly containing various chemical structures derived from natural lignin, heat treatment by thermal annealing is performed to homogenize molecular weight fractionation and structural diversity.

Patent No. 5256679 JP, 2011-256381, A

However, lignin extracted in Patent Document 1 has many components with too low molecular weight, and heat resistance is poor when using lignin as a resin, and in order to improve workability, secondary induction in a separate reaction kettle is required And lignin is not suitable for use as it is.
In Patent Document 2, thermal annealing is carried out at a temperature of 200 ° C. or higher because unreacted phenolic hydroxyl group derived from natural lignin is bonded to another phenolic hydroxyl group or the hydroxyl group is acylated and modified. At the same time, reaction sites derived from natural lignin are simultaneously lost, which is less attractive as a material. Also in this method, it is necessary to separately derivatize the reaction vessel separately.

  The present invention is to provide lignin having high heat resistance without providing a functional group having a hydroxyl group (secondary derivatization) for the purpose of improving reactivity while maintaining the structure derived from natural lignin. .

As a result of intensive studies, the present inventors have found that the above problems can be solved by the production method having the following steps, and completed the present invention.
That is, the present invention provides the following [1] to [10].
[1] A raw material lignin solution is mixed with at least one solvent (a) selected from water having a volume 1 to 50 times the volume of the raw material lignin solution and a hydrocarbon having a dipole moment of 0.25 d or less The manufacturing method of heat-resistant lignin including process (I).
[2] The raw material lignin solution is a lignin solution obtained by solubilizing lignin from plant biomass in a solvent containing an organic solvent, or a solution obtained by dissolving solid lignin in a solvent containing an organic solvent, The manufacturing method of the heat resistant lignin as described in [1].
[3] The method for producing heat-resistant lignin according to the above [2], wherein the organic solvent is at least one selected from an alcohol, an ether and a ketone compound.
[4] The heat resistance described in any one of the above [1] to [3], which further requires the following step (II-1) when the solution obtained in the step (I) has two phases Production method of lignin:
(II-1) The organic phase containing heat-resistant lignin is separated from the solution obtained in step (I), and the organic phase is concentrated.
[5] The heat resistance according to any one of the above [1] to [3], which further requires the following step (II-2) when the solution obtained in the step (I) has one phase. Production method of lignin:
(II-2) Solid-liquid separation of the solution.
[6] (1) a dynamic viscoelasticity measuring method (DMA method) a glass transition temperature T _g is 70 ° C. or higher by, (2) the number average molecular weight of 600 or more, and (3) a differential thermal and thermogravimetric The heat-resistant lignin obtained by the manufacturing method as described in any one of said [1]-[5] whose 5% thermal weight loss start temperature in simultaneous measurement (TG-DTA measurement) is 210 degreeC or more.
[7] The heat resistant lignin according to the above [6] which further satisfies the following requirements (4) and (5): (4) integrated molecular weight obtained by gel permeation chromatography (GPC) using polystyrene as a conversion standard In the distribution curve, the proportion of components having a molecular weight of 320 or less is 15% or less, and (5) an integral molecular weight distribution curve obtained by gel permeation chromatography (GPC) based on polystyrene as a conversion standard has a molecular weight of 3200 or more The ratio of the component which is is 7% or more and 50% or less.
[8] A resin composition containing the heat-resistant lignin according to the above [6] or [7], and a molded article obtained by using the resin composition.
[9] A resin is added to the raw material lignin solution to obtain a lignin-resin-containing solution (IA), the lignin-resin-containing solution, and the lignin-resin-containing solution at a volume 1 to 50 times the volume. Mixing the water and at least one solvent (a ') of a solvent selected from hydrocarbons having a dipole moment of 0.25 d or less (IB), and a method for producing a lignin-containing resin composition .
[10] A lignin-containing resin composition obtained by the method according to the above [9] and a molded article obtained by using the resin composition.

  According to the present invention, lignin with high heat resistance can be provided without secondary derivatization while maintaining the structure derived from natural lignin.

  Hereinafter, embodiments of the present invention will be described in detail.

<Method of producing heat resistant lignin>
The method for producing heat-resistant lignin according to the present embodiment includes at least one selected from a raw material lignin solution, water having a volume 1 to 50 times the volume of the raw material lignin solution, and a hydrocarbon having a dipole moment of 0.25 d or less. It is characterized in that it comprises the step (I) of mixing with a solvent (a) of a species.

[Plant biomass]
Examples of plant biomass include woody biomass and herbaceous biomass. Examples of woody biomass include conifers such as cedar, cypress, hiba, cherry, eucalyptus, beech and bamboo, and hardwoods.
As herbaceous biomass, there are palm palm trunk / empty, palm palm fiber and seeds, bagasse (sugarcane and high biomass amount sugarcane squeezed), cane top (sugarcane top and leaf), energy cane, rice straw, straw, Corn cobs / stalks / leaves (corn stover, corn cob, corn hull), sorghum (including sweet sorghum) residue, hides and shells of Jatropha seeds, cashew shells, switchgrass, erianthus, high biomass yield crops, energy crops, etc. Can be mentioned.
Among them, herbaceous biomass is preferable from the viewpoint of easy availability and compatibility with the production method applied in the present invention, and it is preferable that the biomass is herbaceous biomass, palm palm empty straw, straw, corn foliage, bagasse, cane top, energy cane The residue after extraction of those useful components is more preferable, and bagasse, cane top and energyane are more preferable. Useful ingredients include, for example, hemicellulose, carbohydrates, minerals, water and the like.
The bagasse contains about 5 to 30% by mass of lignin. In addition, lignin in bagasse contains all of H nucleus, G nucleus and S nucleus as a basic skeleton. The G nucleus is one having one methoxy group (-OCH ₃ ) at the ortho position of the phenol skeleton, the S nucleus is one having two methoxy groups at the ortho position, and the H nucleus is It does not have a methoxy group at the ortho position. The lignin derived from woody biomass does not contain H nuclei.
Plant-based biomass can also be used after being crushed. It may be in the form of a block, a chip, a powder, or a water-containing hydrate.

  As a raw material lignin solution, a lignin solution (i) obtained by solubilizing lignin from plant biomass in a solvent containing an organic solvent, or a solution (ii) obtained by dissolving solid lignin in a solvent containing an organic solvent It can be mentioned.

  As the above solution (i) as a raw material lignin solution, for example, lignin contained in the biomass can be solubilized in a solvent containing an organic solvent by separating plant biomass by the existing method. It is possible and is not particularly limited. For example, a method of treating plant biomass in a mixed solvent of water and aliphatic alcohol having 4 to 10 carbon atoms described in WO 2014/142289, and water described in Japanese Patent No. 5256679 Methods of treating plant biomass by

For example, as a specific example of the method of obtaining the raw material lignin solution (i) of the present application, plant biomass is treated with a mixed solvent of water and aliphatic alcohol (solvent containing an organic solvent). Lignin can be separated by processing under the conditions of a specific feed concentration, a specific reaction temperature and time. Here, the preparation concentration of the plant biomass with respect to the solvent containing the organic solvent is preferably 1% by mass or more and 50% by mass or less, more preferably 3% by mass or more and 20% by mass or less, still more preferably 5% by mass or more and 18% by mass % Or less. When the concentration of plant biomass is 1% by mass or more, the energy efficiency of the process of solubilizing lignin is well maintained. On the other hand, when the concentration of plant biomass exceeds 50% by mass, the amount of solvent is not sufficient, and the separation efficiency of lignin decreases.
The treatment reaction temperature is preferably 100 ° C. or more and 350 ° C. or less, more preferably 150 ° C. or more and 300 ° C. or less, and still more preferably 170 ° C. or more and 270 ° C. or less. When the temperature is 100 ° C. or higher, the separation of lignin is promoted, and when the temperature exceeds 350 ° C., the generation of coke due to the decomposition of cellulose and the repolymerization of lignin can be suppressed.
The treatment reaction time is 0.1 hour or more and 10 hours or less, preferably 0.2 hours or more and 8 hours or less, more preferably 1 hour or more and 6 hours or less, still more preferably 1 hour or more It is less than 3 hours. If it is 0.1 hours or more, the separation of lignin proceeds sufficiently, and if it is within 10 hours, the formation of coke due to the decomposition of cellulose and the repolymerization of lignin can be suppressed.

  When the raw material lignin solution is the above solution (ii), any solid lignin can be used without particular limitation. For example, solid lignin obtained by solubilizing lignin from plant biomass described above and then concentrating, solid lignin obtained from black liquor produced in the pulp production process, cellulose in the process of saccharifying plant biomass, The residue etc. which hydrolyze hemicellulose and took out sugar can be used.

The organic solvent is not particularly limited, but may be any selected from saturated or unsaturated linear alcohols and branched alcohols. In addition, ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran, ethylene glycol and polyethylene glycol may be used. The organic solvent may be used alone or in combination of two or more.
Among them, at least one selected from methanol, ethanol, propanol, 1-butanol, 2-methyl-1-propanol, 2-butanol, 2-methyl-2-propanol, pentanol, hexanol, heptanol, octanol, acetone and tetrahydrofuran Is more preferably at least one selected from 1-butanol, 2-methyl-1-propanol, 2-butanol, ethanol, pentanol, hexanol and acetone; More preferably, it is at least one selected from propanol, 2-butanol, ethanol and acetone, more preferably 1-butanol, 2-methyl-1-propanol, 2-butanol, and 1-butanol. It is particularly preferred. As a solvent containing the said organic solvent, the mixed solvent of these organic solvents and water, for example can be mentioned.

In the raw material lignin solution, the concentration of lignin at 25 ° C. in an organic solvent is preferably 1% by mass or more and 90% by mass or less.
It is not preferable that the concentration of lignin at 25 ° C. is less than 1% by mass, since the energy efficiency of the process for producing heat resistant lignin deteriorates. When the concentration of lignin at 25 ° C. exceeds 90% by mass, it is not preferable because the degree of purification in the subsequent step (I) is inferior.
The concentration of lignin at 25 ° C. is preferably 1% by mass to 70% by mass, more preferably 1% by mass to 50% by mass, still more preferably 2% by mass to 40% by mass, particularly preferably 4% by mass or more It is 30 mass% or less. In addition, when using multiple types of organic solvents, the density | concentration of the said lignin means the density | concentration in the total amount of an organic solvent.

前記炭化水素の双極子モーメントは、好ましくは０．２３ｄ以下であり、より好ましくは０．２０ｄ以下である。[Step (I)]
In the step (I) in the present embodiment, at least the raw material lignin solution, water having a volume 1 to 50 times the volume of the raw material lignin solution, and a hydrocarbon having a dipole moment of 0.25 d or less Mix with one solvent (a). The step (I) corresponds to the step of purifying lignin in the raw material lignin solution. By passing through the said process process, the heat resistant lignin which is excellent in heat resistance can be obtained.
As water, for example, tap water, industrial water, ion exchanged water, distilled water or the like can be used.
As a hydrocarbon having a dipole moment of 0.25 d or less, a saturated chain hydrocarbon, unsaturated chain hydrocarbon, saturated cyclic hydrocarbon or unsaturated cyclic hydrocarbon having 5 to 8 carbon atoms is preferable. . When the dipole moment of the hydrocarbon exceeds 0.25 d, the purification efficiency is lowered, and it is not preferable because lignin having high heat resistance can not be obtained. Here, "dipole moment" is a value calculated by Winmostar MOPAC AMI (MOP6W70). An example of a compound that can be used as such a hydrocarbon is shown below along with its dipole moment value.

The dipole moment of the hydrocarbon is preferably 0.23 d or less, more preferably 0.20 d or less.

  When the amount of water and at least one solvent (a) selected from hydrocarbons having a dipole moment of 0.25 d or less when mixed with the raw material lignin solution is less than 1 time by volume, it is contained in the raw material lignin solution Light components can not be sufficiently removed. On the other hand, when the amount of the solvent (a) exceeds 50 times by volume, the target heat resistant lignin can not be efficiently recovered due to the increase of waste water, the increase of the amount of hydrocarbons used and the like. In addition, when using multiple types of hydrocarbon solvents, the quantity of the said solvent (a) means the total amount of water and several types of hydrocarbon solvents.

The amount of the solvent (a) to be mixed with the raw material lignin solution is preferably 1 to 40 times, more preferably 1 to 30 times, further preferably 2 to 20 times the volume of the raw material lignin solution. It is preferably twice or less, particularly preferably 2 to 15 times.
The mixing method is not particularly limited as long as the lignin-resin-containing solution and the solvent (a) can be uniformly mixed. The apparatus used for mixing includes, for example, edge runners, stirring mixers, roll mills, cone mills, flat stone mills, speed line mills, ball mills, bead mills, bead mills, sand mills, pearl mills, attritors, vertical mixers, kneaders, high speed agitation Machine (dissolver) etc. can be mentioned.

Through the step (I), lignin in the raw material lignin solution can be purified to obtain heat resistant lignin.
Specifically, in step (I), light components contained in the raw material lignin solution can be removed. Examples of light components include phenols such as vanillin, and sugar perhydrolysates such as furfural, but are not particularly limited.

  The solution temperature in the above step (I) of mixing the raw material lignin solution with at least one solvent (a) selected from water and hydrocarbon having a dipole moment of 0.25 d or less is the stability of the solution, lignin It is preferable that the temperature is 0 ° C. or more and 100 ° C. or less in view of solubility in a solution and the like. The solution temperature is more preferably 10 ° C. or more and 90 ° C. or less, still more preferably 20 ° C. or more and 80 ° C. or less, and particularly preferably 25 ° C. or more and 70 ° C. or less.

  When mixing the raw material lignin solution with at least one solvent (a) selected from water and a hydrocarbon having a dipole moment of 0.25 d or less in step (I), stirring is carried out as necessary. You may go. When stirring is performed, stationary separation may be further performed as necessary. The standing time is usually from 1 minute to 120 minutes. If the standing time is one minute or more, the heat resistant lignin and the other light components can be sufficiently separated. Moreover, the upper limit of stationary time is enough for 120 minutes. The standing time is preferably 5 minutes to 100 minutes, more preferably 10 minutes to 60 minutes, and still more preferably 15 minutes to 30 minutes.

[Step (II-1) or (II-2)]
In the present embodiment, it is preferable to perform the following step (II-1) or (II-2) depending on whether the solution obtained by the step (I) is biphasic or monophasic.
When the solution obtained in step (I) is biphasic, it is preferable to carry out step (II-1) continuously after step (I). In the step (II-1), the phase containing the heat-resistant lignin obtained by the step (I) is separated from the above two phases, the separated phase is concentrated, and the obtained solid content is dried. For example, when the solution obtained by step (I) is divided into two phases of an aqueous phase and an organic phase, or an aqueous phase, and an organic phase and a hydrocarbon phase having a dipole moment of 0.25 d or less Since the target heat-resistant lignin is dissolved in the organic phase side, the organic phase side is separated in step (II-1), the organic phase side is concentrated, and the obtained solid content is dried. . Here, the “organic phase side” separates from the aqueous phase when a single phase is formed of a hydrocarbon phase having a dipole moment of 0.25 d or less and an organic phase containing heat resistant lignin, It means a single phase containing the above organic phase. Naturally, in the case of separation into two phases of an aqueous phase and an organic phase, the “organic phase side” means an organic phase. When the solution obtained in step (I) is divided into two phases of a hydrocarbon phase having a dipole moment of 0.25 d or less and an organic phase (an organic phase other than the hydrocarbon), an organic phase is obtained. Since the target heat resistant lignin is dissolved, in step (II-1), the organic phase is separated, the organic phase is concentrated, and the obtained solid content is dried. In addition, when solid content is produced | generated in the state of two phases, the organic phase (side) is isolate | separated after solid-liquid separation.
When the solution obtained in step (I) is single phase, that is, when the heat resistant lignin precipitates as a solid, it is preferable to carry out step (II-2) continuously. In the step (II-2), the solution is subjected to solid-liquid separation, and the obtained solid is dried.
If the solution obtained in step (I) has two phases, light components can be removed from the raw material lignin solution by phase separation in step (II-1). When the solution obtained in the step (I) is one phase, the light components can be removed from the raw material lignin solution by solid-liquid separation of the solid precipitated due to the difference in solubility.

<Heat resistant lignin>
The heat resistant lignin obtained by the manufacturing method of the present embodiment described above has the following physical properties:
(1) in a dynamic viscoelasticity measurement (DMA method) a glass transition temperature T _g is 70 ° C. or higher by,
(2) The number average molecular weight is 600 or more, and (3) the 5% thermal weight loss start temperature in differential heat and thermogravimetry simultaneous measurement (TG-DTA measurement) is 210 ° C. or more.

The heat-resistant lignin obtained by the production method of the present embodiment has a glass transition temperature _Tg of 70 ° C. or higher, preferably 75 ° C. or higher, more preferably 80 ° C. or higher, according to the dynamic viscoelasticity measurement (DMA) method. Preferably it is 85 degreeC or more. When the glass transition temperature _Tg is in the above range, lignin having excellent heat resistance can be obtained.

  Moreover, the number average molecular weight (Mn) of the heat resistant lignin obtained by the manufacturing method of this embodiment is 600 or more. The number average molecular weight is obtained by measurement by gel permeation chromatography (GPC) using polystyrene as a conversion standard. According to the manufacturing method of the present embodiment, since lignin having a low molecular weight can be cut, the degree of purification of lignin can be increased, and lignin having excellent heat resistance can be obtained. The number average molecular weight of the heat resistant lignin is preferably 630 or more, more preferably 650 or more.

  In this embodiment, since the 5% thermal weight loss start temperature in TG-DTA measurement of heat-resistant lignin is 210 ° C. or higher, it can be seen that it has high heat resistance. The 5% thermal weight loss start temperature is more preferably 230 ° C. or more.

It is preferable that the heat resistant lignin obtained by the manufacturing method of the present embodiment further satisfy the following requirements (4) and (5).
(4) In the integrated molecular weight distribution curve obtained by gel permeation chromatography (GPC) using polystyrene as a conversion standard, the proportion of components having a molecular weight of 320 or less is 15% or less, and (5) polystyrene as a conversion standard In the integral molecular weight distribution curve obtained by gel permeation chromatography (GPC), the proportion of the component having a molecular weight of 3200 or more is 7% or more and 50% or less.

In the present embodiment, the molecular weight of lignin is obtained by measurement by gel permeation chromatography (GPC) using polystyrene as a conversion standard. In addition, the component whose molecular weight of polystyrene conversion is 320 or less and the component whose molecular weight of polystyrene conversion is 3200 or more were calculated | required from the peak area in the integral molecular weight distribution curve calculated | required by GPC.
In the integral molecular weight distribution curve determined by GPC, the proportion of the component having a molecular weight of 320 or less is 15% or less. Since the proportion of the component having a molecular weight of 320 or less is 15% or less, the amount of monocyclic phenols (light component) having a small molecular weight is small. The proportion of the component having a molecular weight of 320 or less is preferably 11% or less, more preferably 8% or less, and still more preferably 5% or less.
The heat-resistant lignin has a proportion of 7 to 50% of components having a molecular weight of 3200 or more, as determined from the integral molecular weight distribution curve determined by GPC. If the proportion of the component having a molecular weight of 3200 or more is less than 7%, the heat resistance is poor, which is not preferable. In addition, when the proportion of the component having a molecular weight of 3200 or more exceeds 50%, the formability is inferior, which is not preferable. The proportion of the component having a molecular weight of 3200 or more is preferably 10% to 50%, more preferably 10% to 30%.

  The heat resistant lignin (hereinafter sometimes abbreviated as heat resistant lignin) obtained by the production method of the present embodiment may be soluble in an organic solvent and a mixed solvent of an organic solvent and water. The organic solvent is not particularly limited, and examples thereof include alcohols such as methanol, ethanol and butanol, ethers such as dimethyl ether, diethyl ether and tetrahydrofuran, and ketone compounds such as acetone. In particular, the solubility in tetrahydrofuran, acetone (and a mixed solvent with water) is high, and completely soluble at room temperature.

  The amount of 1-butanol reacted with lignin of the heat resistant lignin obtained by the production method of the present embodiment is preferably 10 wt% or less, more preferably 5 wt% or less, still more preferably 2.5 wt% or less, particularly preferably 1 wt% It is below. If it exceeds 10 wt%, the cost of 1-butanol loss will increase unless a significant amount of lignin is added to 1-butanol, which is not preferable in that it causes a decrease in economic efficiency. The lower limit value is not particularly limited, but is usually 0.1 wt% or more.

The amount of 1-butanol reacted with lignin can be measured, for example, by the following method.
The lignin obtained by treating 1-butanol used in the production method of the present embodiment by replacing it with 1-butanol-d ₁₀ is analyzed by ² H-NMR to react with lignin 1 The amount of butanol can be calculated. In order to quantify the amount of 1-butanol reacted with lignin, 3- (trimethylsilyl) -1-propanesulfonic acid-d ₆ sodium salt is added to lignin as an internal standard, and ² H-NMR measurement is performed.

(1) ² H-NMR measurement conditions NMR apparatus: Bruker Biospin KK-made DRX 500
Probe: TCI 5φ Cryoprobe Resonance frequency: 76.77 MHz
Observation range: -2.5 to 12.5 ppm
Observation center: 5.00 ppm
aquistion time: 2.11 seconds
relaxation delay: 5.0 seconds flip angle: 30 °
Pulse width: 200 microseconds NMR sample tube: 5φ
Sample amount: 5 to 15 mg
Solvent: Dimethyl sulfoxide Measurement temperature: Room temperature Accumulation number: 10,000 times (2) Attribution of the amount of 1-butanol reacted with lignin 1-Butanol replaced with 1-butanol-d ₁₀ 1-butanol-d ₁₀ , 3- (trimethylsilyl) -1-propanesulfonic acid-d ₆ sodium salt, observed from δ 3.8 to 4.0 ppm from comparison of ² H-NMR spectra of these three samples peak attributable reacted with 1-butanol -d ₁₀ from the peak and lignin. From the observed range, it is presumed that the aromatic hydroxyl group in lignin reacts with 1-butanol-d- ₁₀ to form an aromatic ether bond.

(3) Method of quantifying 1-butanol-d ₁₀ (wt%) reacted with lignin A: Weight value of lignin (mg)
B: Weight value of 3- (trimethylsilyl) -1-propanesulfonic acid-d ₆ sodium salt (mg)
C: Integral value D derived from 1-butanol reacted with lignin observed near δ 3.8 to 4.0 ppm D: 3- (trimethylsilyl) -1-propanesulfonic acid observed near δ 0.3 to 0.5 ppm -d ₆ integral value of from sodium salt E: 3- (trimethylsilyl) -1-purity F propanoic acid -d ₆ sodium salt: 3- (trimethylsilyl) -1-molar mass of propanesulfonic acid -d ₆ sodium salt a = B × E / (F × 100000)
b = a × F × 1000 × C / 2
1-butanol-d ₁₀ amount (wt%) reacted with lignin = 100 × b / A

<Uses of heat resistant lignin>
The heat-resistant lignin obtained by the manufacturing method according to the present embodiment can be used alone in the application field in which the phenolic resin has been used so far. Moreover, it is also possible to mix | blend the heat resistant lignin which concerns on this embodiment, and another phenol resin, and to manufacture a resin composition.
In addition, since the heat-resistant lignin obtained by the production method according to the present embodiment has a small amount of sulfur compounds and other light components, it can be made into an epoxy-modified product by a known reaction for introducing an epoxy group. Such epoxy-modified heat-resistant lignin is applicable to the application field in which the epoxy resin has been used so far.
Furthermore, the heat resistant lignin obtained by the manufacturing method according to the present embodiment can be used as an additive of a thermoplastic resin.
In the present embodiment, the heat resistant lignin can also be applied as a base resin raw material of phenol resin or epoxy resin, an additive (hardening agent) of epoxy resin, an additive of thermoplastic resin, or the like. This is due to the feature that the heat resistant lignin has a phenolic structural unit. The heat-resistant lignin according to the present embodiment can be used in combination with a curing agent such as an acid anhydride known in the art.

The heat-resistant lignin obtained in the present embodiment can be used as a raw material and an additive for the base resin because the amount of light components (low molecular weight components) is small.
A conventionally known method can be used for use as a base resin raw material. One example is a resin composition in which lignin and a known crosslinking agent represented by hexamethylenetetramine are blended.
Various fillers and general phenol resins obtained industrially may be blended into the resin composition in which lignin and a crosslinking agent are blended, as necessary.
About the use as an additive, the conventionally well-known method mentioned, for example to Unexamined-Japanese-Patent No. 2014-15579, international publication 2016/104634 etc. can be used. Various additives and fillers may be blended into the resin composition, in which lignin and a thermoplastic resin are blended, as necessary.

[Resin composition]
In the present invention, two embodiments of the resin composition containing lignin can be mentioned. The details will be described below.
The resin composition according to the first embodiment contains the above-described heat-resistant lignin. In addition to the above-described heat-resistant lignin, resin components such as thermoplastic resin and thermosetting resin may be contained. The method for producing the resin composition in the present embodiment is not particularly limited, and the resin composition can be obtained by appropriately mixing the above-described heat-resistant lignin and other resin components.
The components other than heat resistant lignin are described below.

<Thermoplastic resin>
The thermoplastic resin that can be added to the resin composition according to the present embodiment is an amorphous thermoplastic resin having a glass transition temperature of 200 ° C. or less, or a crystalline thermoplastic resin having a melting point of 200 ° C. or less Is preferred. The thermoplastic resin includes, for example, polycarbonate resin, styrene resin, polystyrene elastomer, polyethylene resin, polypropylene resin, polyacrylic resin (polymethyl methacrylate resin etc.), polyvinyl chloride resin, cellulose acetate resin, polyamide resin, Low melting point polyester resin (PET, PBT etc.) represented by polyester of a combination of terephthalic acid and ethylene glycol, terephthalic acid and 1,4-butanediol, copolymer containing polylactic acid and / or polylactic acid, acrylonitrile-butadiene -Styrene resin (ABS resin), polyphenylene oxide resin (PPO), polyketone resin, polysulfone resin, polyphenylene sulfide resin (PPS), fluorocarbon resin, silicon resin, polyimide resin, polybenzimide Tetrazole resins, polyamide elastomers, and copolymers thereof with other monomers.
The resin composition according to the present embodiment may contain, in addition to the above-described cellulose-containing solid and thermoplastic resin, a resin compatible with the thermoplastic resin composition, an additive, and a filler.

<Thermosetting resin>
The thermosetting resin that can be blended into the resin composition according to the present embodiment is not particularly limited. For example, as a phenol resin, novolak-based phenol resin and resol-based phenol resin can be mentioned, and these may be used alone or in combination. Other common thermosetting resins such as epoxy resin, polyurethane resin, melamine resin, urea resin, unsaturated polyester resin, silicone resin, and alkyd resin can also be used.
Similar to lignin, it is preferable to use a phenolic resin among the above thermosetting resins because it has a phenolic hydroxyl group, can react with lignin, and can be used as a diluent for lignin. .

A lignin reactive compound having a functional group capable of reacting with lignin may be blended as a thermosetting resin that can be blended in the resin composition according to the present embodiment. Examples of the compound having a functional group capable of reacting with lignin include (e) a compound which causes electrophilic substitution reaction with a phenol compound, (f) a compound having an epoxy group, and (g) a compound having an isocyanate group. The thermosetting resin (e) to (g) may be blended together with the above-mentioned phenol resin in consideration of physical properties such as processability of a resin composition, strength of a molded article, and heat resistance.
Since lignin has a phenolic structural unit, it can be applied as a base resin raw material such as phenol resin and epoxy resin, an additive (hardening agent) of epoxy resin, and the like.

(E) Compound That Produces Electrophilic Substitution Reaction with Phenolic Compound The compound that produces electrophilic substitution reaction with the phenolic compound includes formaldehyde, a formaldehyde donor curing agent compound, or a formaldehyde equivalent compound. Commercially, hexamethylenetetramine, hexaformaldehyde and paraformaldehyde can be used.

(F) Compound Having an Epoxy Group The compound having an epoxy group belongs to a category called a so-called epoxy resin. For example, 2,2-bis (4-hydroxyphenyl) propane (referred to as bisphenol A), bis (2-hydroxyphenyl) methane (referred to as bisphenol F), 4,4'-dihydroxydiphenyl sulfone (Referred to as bisphenol S), 4,4'-dihydroxybiphenyl, resorcin, saligenin, trihydroxydiphenyldimethylmethane, tetraphenylol ethane, their halogen-substituted and alkyl-substituted products, butanediol, ethylene glycol, erythritol And a glycidyl ether epoxy resin synthesized from a compound containing two or more hydroxyl groups in the molecule such as novolac, glycerin, polyoxyalkylene and the like and epichlorohydrin etc .; containing two or more such hydroxyl groups in the molecule Compounds and Glycidyl ester epoxy resins synthesized from glycidyl esters of sulfuric acid, etc .; synthesized from primary amines or secondary amines with epichlorohydrin etc. such as aniline, diaminodiphenylmethane, metaxylene diamine, 1,3-bisaminomethylcyclohexane etc. Epoxy resins containing glycidyl groups such as glycidyl amine epoxy resins; epoxy resins containing no glycidyl group such as epoxidized soybean oil, epoxidized polyolefins, vinylcyclohexene dioxide, dicyclopentadiene dioxide and the like. Among these, preferred are cresol novolac-type and phenol novolac-type epoxy resins which are similar in lignin and chemical structure and compatible with each other.

  When the lignin contained in the thermosetting resin composition which concerns on this embodiment is a compound containing an epoxy group, a hardening accelerator can be added suitably according to the objective of hardening reaction promotion. Specific examples include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2- (dimethylaminomethyl) phenol, 1,8-diazabicyclo (5,4,0) Tertiary amines such as undecene-7, phosphines such as triphenylphosphine, tetrabutyl ammonium salt, triisopropyl methyl ammonium salt, trimethyl decanyl ammonium salt, quaternary ammonium salt such as cetyl trimethyl ammonium salt, triphenyl benzyl Examples thereof include quaternary phosphonium salts such as phosphonium salts, triphenylethyl phosphonium salts and tetrabutyl phosphonium salts, and metal compounds such as tin octylate. As a counter ion of quaternary phosphonium salt, halogen, an organic acid ion, a hydroxide ion etc. are mentioned, Especially, an organic acid ion and a hydroxide ion are preferable.

(G) Compound Having an Isocyanate Group Examples of the compound having an isocyanate group include polyisocyanate, or compounds obtained by reacting polyisocyanate and polyol. As polyisocyanates, aromatic polyisocyanates such as tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), polymeric MDI (MDI-CR), carbodiimide-modified MDI (liquid MDI), and norbornane diisocyanate (NBDI) Aliphatic polyisocyanates such as isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), 4,4'-methylene-bis (cyclohexyl isocyanate) (hydrogenated MDI), xylylene diisocyanate (XDI), and blocked isocyanates It can be mentioned. Among these, tolylene diisocyanate (TDI) and 4,4'-diphenylmethane diisocyanate (MDI) are preferably used.

  A hardening accelerator can be suitably added to the resin composition concerning this embodiment according to the object of hardening reaction promotion. Examples of the curing accelerator include organometallic catalysts of zirconium and aluminum, dibutyltin laurate, phenol salts of DBU, octylate salts, amines, imidazoles and the like, but in terms of colorability, organometallic catalysts, For example, aluminum sec-butylate, aluminum ethylacetoacetate diisopropylate, zirconium tributoxyacetylacetonate, zirconium tetraacetylacetonate and the like are particularly preferable.

<Other resin components>
The resin composition according to the present embodiment may contain, in addition to lignin, resins such as urea resin, melamine resin, silicone resin, unsaturated polyester resin, alkyd resin, polyurethane resin and the like.

<Inorganic filler, organic filler>
The resin composition according to the present embodiment may contain a filler. The filler may be an inorganic filler or an organic filler.
As the inorganic filler, for example, spherical or crushed fused silica, silica powder such as crystalline silica, alumina powder, glass powder, glass fiber, glass flake, mica, talc, calcium carbonate, alumina, hydrated alumina, nitrided Boron, aluminum nitride, silicon nitride, silicon carbide, titanium nitride, zinc oxide, tungsten carbide, magnesium oxide and the like can be mentioned.
Examples of the organic filler include carbon fiber, aramid fiber, paper powder, cellulose fiber, cellulose powder, chaff powder, fruit shell / nut powder, chitin powder, starch and the like.
The inorganic filler and the organic filler may be contained singly or in combination of two or more, and the content thereof is determined according to the purpose. When an inorganic filler and / or an organic filler is contained, it is desirable that the content of the inorganic filler and / or the organic filler is appropriate in order to obtain good physical properties and moldability.

<Other additives>
Various additives can be added to the resin composition according to the present embodiment as long as the properties of the molded product obtained from the resin composition are not impaired. In addition, compatibilizers, surfactants and the like can be added according to the purpose.
As a compatibilizer to be used together with a thermoplastic resin, a resin obtained by adding maleic anhydride, epoxy or the like to a thermoplastic resin to introduce a polar group, such as maleic anhydride modified polyethylene resin, maleic anhydride modified polypropylene resin, various commercially available phases A solubilizer may be used in combination.
Examples of the surfactant include linear fatty acids such as stearic acid, palmitic acid and oleic acid, and branched / cyclic fatty acids with rosins, but not limited thereto.
Furthermore, as additives that can be blended in addition to those described above, flexibilizers, heat stabilizers, UV absorbers, flame retardants, antistatic agents, antifoaming agents, thixotropic agents, mold release agents, antioxidants Agents, plasticizers, stress reducing agents, coupling agents, dyes, light scattering agents, small amounts of thermoplastic resins and the like.

<Resin molded products>
A molded article can be obtained from the above resin composition containing heat resistant lignin.
As a method of shape | molding to a predetermined | prescribed shape, if a resin composition can be shape | molded, it will not be specifically limited. For example, when the resin composition is a thermosetting resin composition, compression molding method, injection molding method, transfer molding method, middle molding, FRP molding method and the like can be mentioned as a method of molding into a predetermined shape. Moreover, when a resin composition is a thermoplastic resin composition, an extrusion molding method, an injection molding method, etc. are mentioned as a method of shape | molding to a predetermined shape.

  Examples of molded articles include those obtained by curing a resin composition comprising a heat-resistant lignin and a crosslinking agent, various fillers, and industrially obtainable general phenolic resins, if necessary. Those obtained by forming into a predetermined shape and then curing, or those obtained by forming and processing after being cured, and those obtained by forming and processing a resin composition obtained by mixing a heat resistant lignin with a thermoplastic resin can be mentioned. Molded articles of such resin compositions are heat insulation materials for housing, electronic parts, resins for flax sand, resins for coated sand, resins for impregnation, resins for lamination, resins for FRP molding, automobile parts, reinforcement of automobile tires It can be used for materials, office automation equipment, machines, information communication equipment, industrial materials, etc.

The resin composition in the second embodiment comprises the following steps:
Adding a resin to the raw material lignin solution to obtain a lignin-resin-containing solution (IA);
At least one solvent of the lignin-resin-containing solution, and a solvent selected from water and a hydrocarbon having a dipole moment of 0.25 d or less by volume to 1 to 50 times the volume of the lignin-resin-containing solution Process of mixing with (a ') (IB)
And a lignin-containing resin composition obtained by a method comprising:
The raw material lignin solution is as described above. That is, lignin solution (i) obtained by solubilizing lignin from plant biomass in a solvent containing an organic solvent, or solution (ii) in which solid lignin is dissolved in a solvent containing an organic solvent can be mentioned. The details, preferred embodiments and the like are the same.
The compounding amount of the resin in the above step (IA) is preferably 10 to 2000 with respect to 100 parts by mass of lignin solid content of the raw material lignin solution from the viewpoint of obtaining a lignin-containing resin composition having high strength. It is a mass part, More preferably, it is 20-1000 mass parts, More preferably, it is 50-500 mass parts.

The resin used in step (IA) is not particularly limited as long as it is a resin that dissolves in the raw material lignin solution, and may be a thermosetting resin or a thermoplastic resin. The resin component is as described above, and the preferable ones for each resin component are also the same. Considering a molding method for molding a molded article suitable for use in the lignin-containing resin composition, it is more preferable to use a thermosetting resin.
As resin used at process (IA), phenol resins, such as the novolak-type phenol resin mentioned above, resol-type phenol resin, etc. can be used, for example. Further, other general thermosetting resins and thermoplastic resins described above can also be used.
Similar to lignin, a phenolic resin is preferable among the above-mentioned resins because it has a phenolic hydroxyl group, can react with lignin, and can be used as a diluent for lignin, and novolac phenolic resin and resol More preferred is at least one phenolic resin selected from the group consisting of phenolic resins.

From the lignin-containing resin composition, in the above step (IB), the amount of water and at least one solvent (a ′) selected from hydrocarbons having a dipole moment of 0.25 d or less is less than 1 volume by volume Light components derived from the raw material lignin solution can not be removed sufficiently. On the other hand, when the amount of the solvent (a ′) exceeds 50 times by volume, the target heat resistant lignin can not be efficiently recovered due to the increase of waste water, the increase of the amount of hydrocarbons used and the like. In addition, when using multiple types of hydrocarbon solvents, the quantity of the said solvent (a ') means the total amount of water and several types of hydrocarbon solvents.
At least one solvent (a ′) of the solvent selected from water and a hydrocarbon having a dipole moment of 0.25 d or less used in step (IB) is the same as the solvent (a) described above. The amount of the solvent (a ′) relative to the lignin-resin-containing solution is preferably 1 to 40 times, more preferably 1 to 30 times, still more preferably 2 to 20 times, particularly preferably 2 It is twice or more and 15 times or less.

The solution temperature in the step (IB) of mixing the lignin-resin-containing solution with at least one solvent (a ') of a solvent selected from water and a hydrocarbon having a dipole moment of 0.25 d or less is the solution stability It is preferable that the temperature is 0 ° C. or more and 100 ° C. or less in view of the nature, the solubility of lignin in the solution, and the like. The solution temperature is more preferably 10 ° C. or more and 90 ° C. or less, still more preferably 20 ° C. or more and 80 ° C. or less, and particularly preferably 25 ° C. or more and 70 ° C. or less.
The mixing method is not particularly limited as long as the lignin-resin-containing solution and the solvent (a ′) can be uniformly mixed. The apparatus used for mixing includes, for example, edge runners, stirring mixers, roll mills, cone mills, flat stone mills, speed line mills, ball mills, bead mills, bead mills, sand mills, pearl mills, attritors, vertical mixers, kneaders, high speed agitation Machine (dissolver) etc. can be mentioned.

  When mixing the lignin-resin-containing solution with water and at least one solvent (a ′) selected from a hydrocarbon having a dipole moment of 0.25 d or less in step (IB), as necessary, Stirring may be performed. When stirring is performed, stationary separation may be further performed as necessary. The standing time is usually from 1 minute to 120 minutes. If the standing time is 1 minute or more, other light components derived from the raw material lignin solution can be sufficiently separated from the lignin-containing resin composition. Moreover, the upper limit of stationary time is enough for 120 minutes. The standing time is preferably 5 minutes to 100 minutes, more preferably 10 minutes to 60 minutes, and still more preferably 15 minutes to 30 minutes.

  Through the step (IB), light components can be separated from lignin contained in the lignin-resin-containing solution. Examples of light components include phenols such as vanillin, and sugar perhydrolysates such as furfural, but are not particularly limited.

In the second embodiment, it is preferable to perform the following step (IIA) or (IIB) depending on whether the mixed solution obtained by the step (IB) is two phase or single phase.
If the solution obtained in step (IB) is biphasic, it is preferred to carry out step (IIA) in succession. In step (IIA), the phase containing the heat-resistant lignin obtained by step (IB) is separated from the above two phases, the separated phase is concentrated, and the obtained solid is dried. For example, when the solution obtained by step (IB) is divided into two phases of an aqueous phase and an organic phase, or an aqueous phase, and an organic phase and a hydrocarbon phase having a dipole moment of 0.25 d or less Since the target heat resistant lignin is dissolved in the organic phase side, in the step (IIA), the organic phase side is separated, the organic phase side is concentrated, and the obtained solid content is dried. Here, the “organic phase side” separates from the aqueous phase when a single phase is formed of a hydrocarbon phase having a dipole moment of 0.25 d or less and an organic phase containing heat resistant lignin, It means a single phase containing the above organic phase. Naturally, in the case of separation into two phases of an aqueous phase and an organic phase, the “organic phase side” means an organic phase. When the solution obtained in step (IB) is divided into two phases of a hydrocarbon phase having a dipole moment of 0.25 d or less and an organic phase (an organic phase other than the hydrocarbon), an organic phase is obtained. Since the target heat resistant lignin is dissolved, in step (IIA), the organic phase is separated, the organic phase is concentrated, and the obtained solid content is dried. In addition, when solid content is produced | generated in the state of two phases, the organic phase (side) is isolate | separated after solid-liquid separation.

When the solution obtained in step (IB) is a single phase, ie, when the target lignin-containing resin composition precipitates as a solid, it is preferable to carry out step (IIB) continuously. In step (IIB), the solution is subjected to solid-liquid separation, and the resulting solid is dried.
If the solution obtained in step (IB) has two phases, light components can be removed from the lignin-containing resin composition by phase separation in step (IIA). When the solution obtained in step (IB) is a single phase, light components can be removed from the lignin-containing resin composition into the solution by solid-liquid separation of the solid precipitated due to the difference in solubility.

The lignin reactive compound, the curing accelerator, the inorganic filler, the organic filler and the other additives which can be used in the method for producing a lignin-containing resin composition according to the second embodiment of the present invention It is the same as that which can be used in the lignin containing resin composition which concerns on 1 embodiment.
The above lignin reactive compound may be added together with the resin in step (IA), or the above lignin reactive compound may be added between step (IA) and step (IB) described later. A process may be provided. Besides, the above-mentioned lignin reactive compound may be added after the step (IIA) or the step (IIB).

  The molded article, the molding method, and the use of the lignin-containing resin composition according to the second embodiment are the same as those of the lignin-containing resin composition according to the first embodiment, as described above.

  Hereinafter, the present embodiment will be more specifically described by way of examples, but the present embodiment is not limited to these.

Production Example 1
A mixed solvent of bagasse (sample size: 3 mm square or less), water and 1-butanol which is an organic solvent (prepared so that water / 1-butanol = 8/1 in molar ratio) as raw materials, internal volume 0 It was placed in a .92 L SUS batch type apparatus. The mass of the mixed solvent consisting of water and butanol was 300 g. The feed concentration of the bagasse was 10% by mass with respect to the above mixed solvent.
After purging the inside of the SUS batch-type apparatus with nitrogen, the temperature was raised to 200 ° C., and the decomposition reaction was performed at a reaction temperature of 200 ° C. for 2 hours. The reaction time was an elapsed time after reaching 200 ° C. In addition, the temperature was measured by a thermocouple. The internal pressure at the time of reaction was 1.9 MPa.
After the treatment was completed, the SUS batch-type apparatus was cooled to around room temperature, and then all the contents were taken out and filtered to separate into biomass residue and liquid phase. Further, the aqueous phase of the filtrate and the 1-butanol phase were liquid / liquid separated by a separatory funnel. The separated 1-butanol phase was used as a raw material lignin solution. The solid content (lignin) concentration was determined by separately concentrating the butanol phase, and it was 50 g / L-butanol phase.

Production Example 2
A mixed solvent of bagasse (sample size: 3 mm square or less), water and 1-butanol which is an organic solvent (prepared so that water / 1-butanol = 8/1 in molar ratio) as raw materials, internal volume 0 It was placed in a .92 L SUS batch type apparatus. The mass of the mixed solvent consisting of water and butanol was 300 g. The feed concentration of the bagasse was 10% by mass with respect to the above mixed solvent.
After purging the inside of the SUS batch type apparatus with nitrogen, the temperature was raised to 200 ° C., and the decomposition reaction was performed at 200 ° C. for 2 hours. The reaction time was an elapsed time after reaching 200 ° C. In addition, the temperature was measured by a thermocouple. The internal pressure at the time of reaction was 1.9 MPa.
After completion of the treatment, the SUS batch-type apparatus was cooled to around room temperature, and then all the contents were taken out and filtered to separate into biomass residue and liquid phase. Further, the aqueous phase of the filtrate and the 1-butanol phase were liquid / liquid separated by a separatory funnel. The separated butanol phase was concentrated and vacuum dried at 125 ° C. to obtain 6.5 g of solid (lignin).

Example 1
In 14 mL of the raw material lignin solution (water + butanol phase) obtained in Production Example 1 (concentration of lignin is 6% by mass, 0.7 g of lignin dissolved in 14 mL of butanol + water mixed solvent), 178 mL of ion exchanged water added. The amount of water was 12.7 times that of the raw material lignin solution. The resulting mixed solution was stirred at 25 ° C. for 15 minutes. The liquid phase after stirring was one phase. The solid was filtered off by filtration and the obtained solid was dried at 125 ° C.
The molecular weight, the thermal weight loss onset temperature, and the glass transition point were determined for the solid. The results are shown in Table 2.

Example 2
10 mL of ion exchanged water was added to 10 mL of the lignin solution obtained in Production Example 1 (the concentration of lignin was 6 wt%, and 0.5 g of lignin was dissolved in 10 mL of butanol + water mixed solvent). The amount of water was 1 times that of the raw material lignin solution. The mixed solution was stirred at 50 ° C. for 15 minutes. The liquid phase after stirring was biphasic. The liquid phase was filtered and no solids remained on the filter. The aqueous and butanol phases were separated, the butanol phase was concentrated and the resulting solid was dried at 125 ° C. The molecular weight, the thermal weight loss onset temperature, and the glass transition point were determined for the solid. The results are shown in Table 2.

Example 3
The same operation as in Example 2 was performed except that the amount of ion exchange water was changed to 20 mL. The amount of water was twice that of the raw material lignin solution. The results are shown in Table 2.
Example 4
The same operation as in Example 2 was performed except that the amount of ion exchange water was changed to 70 mL. The amount of water was 7 times that of the raw material lignin solution. The results are shown in Table 2.
Example 5
The same operation as in Example 2 was carried out except that the amount of ion-exchanged water was adjusted to 20 mL and stirring was conducted at 70 ° C. The amount of water was twice that of the raw material lignin solution. The results are shown in Table 2.
Example 6
The same operation as in Example 2 was carried out except that the amount of ion-exchanged water was adjusted to 70 mL and stirring was performed at 70 ° C. The amount of water was 7 times that of the raw material lignin solution. The results are shown in Table 2.
Example 7
The same operation as in Example 1 was performed except that the stirring was performed at 70 ° C. The amount of water was 13 times that of the raw material lignin solution. The results are shown in Table 3.

Example 8
1 g of the solid obtained in Production Example 2 was completely dissolved in 30 mL of acetone. The concentration of lignin in the solution was 4% by mass. To this acetone solution was added 30 mL of ion exchanged water (1 time relative to the raw material lignin solution). The mixed solution was stirred at 25 ° C. for 15 minutes, and the liquid phase after stirring was one phase. The solid was filtered off by filtration and the obtained solid was dried at 125 ° C. The molecular weight, the thermal weight loss onset temperature, and the glass transition point were determined for the solid. The results are shown in Table 3.
Example 9
The same operation as in Example 8 was carried out except that the amount of ion exchange water was changed to 60 mL. The amount of water was twice that of the raw material lignin solution. The results are shown in Table 3.
Example 10
The same operation as in Example 8 was performed, except that the amount of ion exchange water was changed to 90 mL. The amount of water was three times that of the raw material lignin solution. The results are shown in Table 3.
Example 11
140 mL of heptane was added to 14 mL of the lignin solution (water + butanol phase) obtained in Production Example 1 (the concentration of lignin was 6% by mass, and 0.7 g of lignin was dissolved in 14 mL of butanol + water mixed solvent). The amount of heptane was 10 times that of the raw material lignin solution. The resulting mixed solution was stirred at 25 ° C. for 15 minutes. The liquid phase after stirring was one phase. The solid was filtered off by filtration and the obtained solid was dried at 125 ° C. The molecular weight, the thermal weight loss onset temperature, and the glass transition point were determined for the solid. The results are shown in Table 3.
Example 12
1 g of the solid obtained in Production Example 2 was completely dissolved in 30 mL of acetone. The concentration of lignin in the solution was 4% by mass. Heptane 30 mL (1 time with respect to the raw material lignin solution) was added to this acetone solution. The mixed solution was stirred at 25 ° C. for 15 minutes, and the liquid phase after stirring was one phase. The solid was filtered off by filtration and the obtained solid was dried at 125 ° C. The molecular weight, the thermal weight loss onset temperature, and the glass transition point were determined for the solid. The results are shown in Table 3.

Comparative Example 1
The molecular weight of the solid itself obtained in Production Example 2, the thermal weight loss start temperature, the glass transition point, and the phenolic OH equivalent were determined. The results are shown in Table 3.

[Evaluation method]
1. Molecular weight: number average molecular weight (Mn), mass average molecular weight (Mw)
The mass average molecular weight (Mw) and the number average molecular weight (Mn) were measured by gel permeation chromatography (GPC) using a tetrahydrofuran solvent under the following conditions.
[Measurement condition]
SEC device: HLC-8220 GPC (made by Tosoh Corporation)
Column: TSKgel guardcolumn HXL-H + TSKgel GMH-XL 2 + G2000H-XL 1 (made by Tosoh Corporation)
Solvent: THF (Stabilizer free from Wako Pure Chemical Industries, special grade)
Detector: Differential refractive index (RI) detector, UV detector Concentration: 0.1 w / v%
Injection volume: 100 μl
Flow rate: 1.0 ml / min
Column temperature: 40 ° C
Standard sample for calibration curve: Tosoh TSK standard polystyrene Analysis software: GPC-8020 model II
The component whose molecular weight in polystyrene conversion is 320 or less and the component whose molecular weight in polystyrene conversion is 3200 or more were calculated | required from the integral molecular weight distribution curve obtained by said GPC.
2. Thermal weight reduction start temperature (Td5)
The 5% thermal weight loss start temperature (Td5) was measured by EXSTAR 6000 TG / DTA6200 manufactured by Seiko Instruments Inc. About 10 mg of a sample was weighed in a Pt pan, and the temperature was measured at a temperature rising rate of 10 ° C./min, measurement atmosphere: air at 200 mL / min, at a temperature of 35 ° C. to 800 ° C.
3. Glass transition temperature (T _g )
The glass transition temperature (T _g) were determined by a solid viscoelasticity method (DMA method).
The molding board of lignin obtained by each Example and the comparative example was created using the press, and the sample of 5 mm x 30 mmx1 mm was cut out from the molding board. The measurement was performed using DMA 8000 (manufactured by Perkin Elmer Japan Co., Ltd.) under conditions of a temperature elevation temperature of 2 ° C./min and 1 Hz until the temperature reached 0 ° C. to 300 ° C. or a critical minimum elastic modulus. The peak temperature of the obtained tan δ was taken as the glass transition temperature (T _g ).
4. Phenolic hydroxyl group (OH group) equivalent The phenolic hydroxyl group equivalent was determined with reference to the method described in Energy Fuel 2010, 24, 2723.

  As can be seen from the examples, highly heat resistant lignin was obtained. Since the lignin of this example has high heat resistance, it is not necessary to perform secondary modification such as secondary derivatization. Moreover, since it has the phenolic hydroxyl equivalent derived from natural lignin as it is, it turns out that it can be suitably used also as a material.

  According to this embodiment, lignin with high heat resistance can be provided without secondary derivatization while maintaining the structure derived from natural lignin.

Claims (10)

  A step of mixing a raw material lignin solution with at least one solvent (a) selected from water having a volume of 1 to 50 times that of the raw material lignin solution and a hydrocarbon having a dipole moment of 0.25 d or less A process for producing heat resistant lignin, including I).   The raw material lignin solution is a lignin solution obtained by solubilizing lignin from plant biomass in a solvent containing an organic solvent, or a solution obtained by dissolving solid lignin in a solvent containing an organic solvent. The manufacturing method of the heat-resistant lignin as described.   The method for producing heat-resistant lignin according to claim 2, wherein the organic solvent is at least one selected from an alcohol, an ether and a ketone compound. The manufacturing method of the heat-resistant lignin as described in any one of Claims 1-3 which further requires the following process (II-1), when the solution obtained by process (I) is two phases.
(II-1) The organic phase containing heat-resistant lignin is separated from the solution obtained in step (I), and the organic phase is concentrated. The manufacturing method of the heat-resistant lignin as described in any one of Claims 1-3 which further requires the following process (II-2), when the solution obtained by process (I) is one phase:
(II-2) Solid-liquid separation of the solution. (1) in a dynamic viscoelasticity measurement (DMA method) a glass transition temperature T _g is 70 ° C. or higher by,
(2) The number average molecular weight is 600 or more, and (3) the 5% thermal weight loss start temperature in the differential heat and thermogravimetry simultaneous measurement (TG-DTA measurement) is 210 ° C. or more. Heat resistant lignin obtained by the manufacturing method as described in any one of these. The heat resistant lignin according to claim 6, further satisfying the following requirements (4) and (5):
(4) In an integrated molecular weight distribution curve obtained by gel permeation chromatography (GPC) using polystyrene as a conversion standard, the proportion of components having a molecular weight of 320 or less is 15% or less,
(5) In an integrated molecular weight distribution curve obtained by gel permeation chromatography (GPC) using polystyrene as a conversion standard, the proportion of components having a molecular weight of 3200 or more is 7% or more and 50% or less.   A resin composition comprising the heat-resistant lignin according to claim 6 or 7, and a molded article obtained by using the resin composition. Adding a resin to the raw material lignin solution to obtain a lignin-resin-containing solution (IA);
At least one solvent of the lignin-resin-containing solution, and a solvent selected from water and a hydrocarbon having a dipole moment of 0.25 d or less by volume to 1 to 50 times the volume of the lignin-resin-containing solution Process of mixing with (a ') (IB)
And a method for producing a lignin-containing resin composition.   A lignin-containing resin composition obtained by the method according to claim 9 and a molded article obtained by using the resin composition.