JP2014133817A - Method for manufacturing a lignin derivative and lignin resin molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method capable of easily separating and obtaining a reactive lignin derivative from biomass in a high yield, and to provide a lignin resin molding excellent in terms of distortion at the time of flexural rupture thereof.SOLUTION: The method of the present invention for manufacturing a lignin derivative is a manufacturing method of a lignin obtained by decomposing biomass, including a decomposition step of obtaining a decomposition product by placing biomass in the presence of a mixed solvent including water and a phenol and by decomposing these materials at a high temperature under a high pressure, a recovery step of obtaining a solution of phenols including a lignin derivative in the decomposition product obtained from the decomposition step, and a distillation step of distilling off phenols from the phenol solution component obtained from the recovery step.

Description

  The present invention relates to a method for producing a lignin derivative and a lignin resin molded article.

Many wood-based waste materials (biomass) such as bark, thinned wood, and building waste have been disposed of so far. However, protection of the global environment is becoming an important issue, and from this point of view, the reuse and recycling of wood-based waste materials are being considered.
The main components of common wood are cellulose derivatives, hemicellulose derivatives and lignin derivatives.

Patent Document 1 describes a method in which lignin contained at a ratio of about 30% is used as a resin raw material.
Patent Document 1 discloses that a liquid phenol derivative is infiltrated into wood flour, lignin in the wood flour is solvated with the phenol derivative, and then concentrated acid is added to dissolve the cellulose component to thereby dissolve the lignin. Is disclosed in which a derivatized lignin phenol derivative is separated from the phenol derivative phase.
Furthermore, in Patent Document 1, a solvent in which a phenol derivative is dissolved in wood flour is infiltrated, and then the solvent is distilled off. Thereafter, concentrated acid is added to the remaining wood flour, thereby being solvated by the phenol derivative. A method for obtaining lignin is disclosed.

  Thus, in order to use a lignin derivative as a raw material material for other chemicals and a resin raw material, it is necessary to isolate the lignin derivative from wood.

However, the lignin derivative produced by the above method is reduced by reacting and reducing the reactive phenolic hydroxyl group contained in the lignin derivative due to the chemical treatment in the production process. It was sometimes difficult to get.
In addition, in the lignin derivative produced by the method as described above, a compound such as concentrated acid used in the chemical treatment in the production process remains as an impurity, so that it is difficult to easily isolate and the yield is low. There was a problem.

JP 2001-261839 A

  The objective of this invention is providing the manufacturing method which can isolate | separate easily the lignin derivative which has reactivity from biomass, and can obtain it with a high yield. Another object of the present invention is to provide a lignin resin molded article having excellent distortion at bending fracture.

Such an object is achieved by the present inventions (1) to (9) below.
(1) A method for producing a lignin derivative obtained by decomposing biomass,
A decomposition step in which biomass is placed in the presence of a mixed solvent containing water and phenols, and these are decomposed under high temperature and high pressure to obtain decomposition products;
A recovery step of obtaining a phenol solution containing a lignin derivative from the decomposition product obtained by the decomposition step;
A distillation step of distilling off phenols from the phenol solution obtained by the recovery step;
A process for producing a lignin derivative characterized by comprising:
(2) The manufacturing method of the lignin derivative as described in (1) whose weight of the phenols in the said decomposition | disassembly process is 100-2000 weight part with respect to 100 weight part of biomass.
(3) The method for producing a lignin derivative according to (1) or (2), wherein the content of phenol in the mixed solvent containing water and phenol in the decomposition step is 10 to 75% by weight.
(4) The method for producing a lignin derivative according to any one of (1) to (3), wherein the molecular weight of the phenol in the mixed solvent containing water and phenol in the decomposition step is 90 or more and 300 or less.
(5) The said decomposition process is a manufacturing method of the lignin derivative in any one of (1) thru | or (4) which decomposes | disassembles by process temperature 150-350 degreeC and process pressure 1-40 Mpa.
(6) The said decomposition process is a manufacturing method of the lignin derivative in any one of (1) thru | or (5) which decomposes | disassembles in processing time 5 to 480 minutes or less.
(7) A lignin derivative obtained by the method for producing a lignin derivative according to any one of (1) to (6).
(8) A lignin resin composition comprising the lignin derivative according to (7).
(9) A lignin resin molded article obtained by curing the lignin resin composition according to (8).

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the manufacturing method which can isolate easily the lignin derivative which has reactivity from biomass, and can obtain it with a high yield. Moreover, it becomes possible to provide a lignin resin molding. As a result, it becomes possible to provide a resin composition and a resin substrate excellent in strain at the time of bending fracture at low cost.

  Hereinafter, the manufacturing method of the lignin derivative of this invention and the lignin resin molding are demonstrated in detail based on suitable embodiment.

<Method for producing lignin derivative>
First, the manufacturing method of the lignin derivative of this invention is demonstrated.

  As described above, the method for producing a lignin derivative in the present invention decomposes biomass and separates the lignin derivative.

A method for producing a lignin derivative for separating a lignin derivative obtained by decomposing the biomass of the present invention,
A method for producing a lignin derivative obtained by decomposing biomass,
A decomposition step in which biomass is placed in the presence of a mixed solvent containing water and phenols, and these are decomposed under high temperature and high pressure to obtain decomposition products;
A recovery step of obtaining a phenol solution containing a lignin derivative from the decomposition product obtained by the decomposition step;
A distillation step of distilling off phenols from the phenol solution obtained by the recovery step;
have.

Hereinafter, each process will be described sequentially.
[1] Decomposition process A decomposition process in which biomass is placed in the presence of a mixed solvent containing water and phenols, and these are decomposed under high temperature and high pressure to obtain a decomposed product will be described.
By this step, the biomass can be decomposed into lignin derivatives.

  First, biomass is placed in the presence of a mixed solvent containing water and phenols.

  The biomass is a plant or a processed product of a plant containing a lignin derivative. Examples of the plant include broad-leaved trees such as beech, birch and oak, conifers such as cedar, pine, and oak, grasses such as bamboo and rice straw, and coconut shells.

  Moreover, although the shape of the said biomass is not specifically limited, A block shape, a chip shape, a powder form etc. are mentioned.

  Further, the biomass preferably has a size of about 100 μm to 1 cm, and more preferably about 200 to 1000 μm. By using biomass of such a size, it is possible to improve the dispersibility of the biomass in the liquid and to efficiently perform the biomass decomposition treatment.

  As the solvent used in the decomposition step in the present invention, a mixed solvent containing water and phenols is used. Among these, as water, for example, ultrapure water, pure water, distilled water, ion exchange water, or the like is used.

  On the other hand, the phenol contained in the mixed solvent is not particularly limited as long as it has a phenolic hydroxyl group. For example, phenol, o-cresol, m-cresol, p-cresol, catechol, resorcinol, pyrogallol, cardanol, Eugenol, guaiacol, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, gallic acid, tannic acid, etc. may be used, and one or a combination of two or more of these may be used. it can.

  The molecular weight of the phenols is preferably 90 or more and 300 or less, and more preferably 93 or more and 280 or less. When the molecular weight of the phenol is within the above range, the lignin derivative can be easily recovered because it can be easily obtained as a phenol solution in the recovery step described later.

  The higher the weight of phenols in the decomposition step, the better, but it is preferably 100 to 2000 parts by weight, more preferably 150 to 1000 parts by weight, with respect to 100 parts by weight of biomass. Most preferred is 200 to 500 parts by weight. When the weight of the phenol is within the above range, the solubility of the lignin derivative in a phenol solution described later can be improved. As a result, since the lignin derivative can be efficiently recovered when the phenol solution is recovered in the recovery step described later, the yield of the lignin derivative can be improved.

Moreover, it is preferable that content of the phenols of the mixed solvent containing water and phenols in the said decomposition process is 10 to 75 weight%, and 15 to 70 weight% is further more preferable. When the content of the phenols is within the above range, the mixed solution containing water and phenols is separated into a solution layer mainly containing water and a solution layer mainly containing phenols. By collecting, the lignin derivative can be easily collected.
Furthermore, when the weight of the phenols in the decomposition step is within the above range, not only can the lignin derivative be recovered easily, but also the yield of the lignin derivative can be improved.

It is inferred that the degradation of natural lignin contained in the biomass proceeds by a cleavage reaction of benzyl aryl ether present in the natural lignin. Here, when the natural lignin is decomposed with water, the active species generated in the natural lignin by a cleavage reaction recombines within the natural lignin molecule, so that the obtained lignin derivative becomes high molecular weight and insoluble. In some cases, it may be obtained as a fraction, and it may be expensive to recover the insolubilized lignin derivative.
However, when the biomass is decomposed with a mixed solvent containing water and phenols, the active species generated in the natural lignin by the cleavage reaction of the benzyl aryl ether present in the natural lignin reacts with the phenols. The lignin derivative having a molecular weight can be obtained. Since such a lignin derivative can be dissolved in the phenols, most of the lignin derivative can be obtained by recovering the phenol solution in the recovery step described later. As a result, not only can the lignin derivative be easily recovered, but also the yield of the lignin derivative can be improved.

  The mixed solvent may contain other solvents in addition to water and phenols. The content of the other solvent in the mixed solvent is less than each of water and phenols, and is preferably 10% by mass or less and more preferably 5% by mass or less of the total amount of the mixed solvent. When the content of the other solvent is within the above range, it is possible to easily recover the phenol solution containing the lignin derivative in the separation step described later without impairing the decomposition of the biomass in the decomposition step.

  Examples of other solvents include ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, cyclic ethers such as tetrahydrofuran and dioxane, nitriles such as acetonitrile, N, N-dimethylformamide, N, N-dimethyl. Examples include amides such as acetamide and n-methylpyrrolidone, alkyl halides such as methylene chloride and chloroform, and one or a combination of two or more of these can be used.

  By decomposing the biomass in the presence of such a mixed solvent under high temperature and high pressure (decomposition step), the biomass is decomposed into a lignin derivative.

  In the generation of a high temperature and high pressure environment, a pressure vessel such as an autoclave is used. Moreover, as this pressure vessel, what is equipped with a heating means and a stirring means is used preferably, and it is preferable to stir biomass under high temperature and pressure. Moreover, you may provide the means to pressurize independently from the factor which influences pressure, such as the temperature in a container, as needed. Examples of such means include means for introducing an inert gas such as argon gas into the container.

The treatment temperature in the decomposition treatment is preferably 150 to 350 ° C, and more preferably 200 to 300 ° C. When the treatment temperature is within the above range, gasification due to thermal decomposition can be suppressed, so that a lignin derivative can be obtained in high yield.
Further, when the treatment temperature is within the above range, the molecular weight of the lignin derivative can achieve both reactivity and meltability or solubility. In addition, when processing temperature is less than the said lower limit, the molecular weight of a lignin derivative becomes higher than necessary, and there exists a possibility that it may be inferior to solubility and a meltability. On the other hand, when the treatment temperature exceeds the upper limit, the molecular weight of the lignin derivative becomes unnecessarily low, and the reactivity may decrease when used as a resin raw material.

  Moreover, it is preferable that the processing time in a decomposition process is 5-480 minutes, and it is more preferable that it is 7-120 minutes. If the treatment time is within the above range, the ratio of aromatic protons and aliphatic protons of the lignin derivative obtained after decomposition is an appropriate value, and optimization is performed from the viewpoint of compatibility between reactivity and meltability or solubility. Can do.

  Furthermore, the pressure in the decomposition treatment is preferably 1 to 40 MPa, and more preferably 1.5 to 20 MPa. When the pressure is within the above range, the biomass decomposition efficiency can be significantly increased, and the processing time can be shortened accordingly. If necessary, the pressure inside the pressure vessel may be increased with argon gas or the like to increase the pressure.

  The treatment conditions in the decomposition step are preferably a combination of a treatment temperature of 150 to 350 ° C., a treatment time of 5 to 480 minutes, a treatment pressure of 1 to 40 MPa, a treatment temperature of 200 to 300 ° C., a treatment time of 7 to 120 minutes, and a treatment pressure. A condition in which 1.5 to 20 MPa is combined is more preferable. When the treatment conditions are the above conditions, the yield of lignin derivative can be further increased.

  In addition, you may make it add the catalyst which accelerates | stimulates a decomposition process to a solvent as needed. Examples of the catalyst include inorganic bases such as sodium carbonate.

  Furthermore, as a pretreatment for the decomposition step, it is preferable to perform a step in which the biomass and the solvent are sufficiently agitated to allow them to blend. Thereby, the decomposition of biomass can be particularly optimized.

  In addition, as stirring temperature, it is preferable that it is about 0-150 degreeC, and it is more preferable that it is about 10-130 degreeC.

  Moreover, as stirring time, it is preferable that it is about 1 to 120 minutes, and it is more preferable that it is about 5 to 60 minutes.

  Further, examples of the stirring method include various mills such as a ball mill and a bead mill, a method using a stirrer equipped with a stirring blade, a method using water flow stirring using a homogenizer, a jet pump, and the like.

  The solvent used in the decomposition step is preferably used in a subcritical or supercritical state (condition). It is considered that the solvent in the subcritical or supercritical state contributes to the acceleration of the biomass decomposition process. For this reason, the efficiency of a decomposition process can be improved more, the manufacturing cost of a lignin derivative can be reduced, and the manufacturing process can be simplified.

  Furthermore, since the solvent used in the decomposition step is a mixed solvent containing water and phenols as described above, it is preferable that both water and phenols are in a subcritical or supercritical state. Even if is a subcritical or supercritical state, a sufficient effect can be obtained.

  As an example, the critical temperature of water is about 374 ° C., the critical pressure is about 22.1 MPa, the critical temperature of phenol is about 421 ° C., and the critical pressure is about 6.1 MPa.

[2] Recovery Step Next, a recovery step for obtaining a phenol solution containing a lignin derivative from the decomposition product obtained in the decomposition step will be described.
In this step, the phenol solution containing the lignin derivative can be separated and recovered from the decomposition product.

The decomposition treatment product obtained by the decomposition step includes a phenol solution containing a lignin derivative and an aqueous solution. Therefore, the lignin derivative can be recovered and obtained by recovering the phenol solution containing the lignin derivative. The method for recovering the phenol solution containing the lignin derivative is not particularly limited as long as it can remove solids and the like. Examples thereof include centrifugation and filtration, but filtration is preferable from the viewpoint of workability.
Further, when the decomposition product is phase-separated into a phenol solution layer containing a lignin derivative and an aqueous solution layer, the aqueous solution layer is separated using, for example, a separatory funnel or a dropper By this, a phenol solution containing a lignin derivative can be recovered.

[3] Distillation step Further, a distillation step for distilling off phenols from the phenol solution obtained in the recovery step will be described.
In this step, the phenols can be removed from the phenol solution containing the lignin derivative, and the lignin derivative can be recovered.

  The lignin derivative can be recovered and obtained by distilling off the phenols from the phenol solution obtained by the recovery step. The method for distilling off is not particularly limited, and examples thereof include a method for reducing the pressure and a method for heating, and these methods may be used in combination. Specifically, the distillation operation can be performed using, for example, a vacuum distillation apparatus or an evaporator. By this step, phenols and water can be volatilized and removed, the lignin derivative dissolved in the phenols can be insolubilized, and the lignin derivative can be recovered.

  The lignin derivative produced by the method for producing a lignin derivative is a compound having a phenol derivative as a unit structure. Since this unit structure has a chemically and biologically stable carbon-carbon bond or carbon-oxygen-carbon bond, it is less susceptible to chemical degradation and biological degradation. For this reason, a lignin derivative is useful as a resin raw material.

  Specific examples of the lignin derivative include a guaiacylpropane structure represented by the following formula (1), a syringylpropane structure represented by the following formula (2), and a 4-hydroxyphenylpropane structure represented by the following formula (3). Can be mentioned.

Further, the lignin derivative obtained in the present invention is preferably one in which at least one of the ortho-position and para-position of the aromatic ring is unsubstituted with respect to the hydroxyl group. Such a lignin derivative is excellent in reactivity because it contains a large number of reaction sites where a curing agent acts due to electrophilic substitution reaction on the aromatic ring and steric hindrance can be reduced in the reaction with a hydroxyl group.
Here, the lignin derivative may contain a lignin degradation product, a cellulose degradation product, and a hemicellulose degradation product, with a compound having a lignin skeleton as a main component. In addition, the said main component shows that content in a lignin derivative exceeds 50 weight%.

  In addition, the lignin derivative obtained in the present invention preferably has a polystyrene-equivalent number average molecular weight of 200 to 2000 as measured by gel permeation chromatography, and more preferably 300 to 1800. Such a lignin derivative having a number average molecular weight has a higher balance between reactivity (curability) and meltability or solubility. For this reason, the utilization as a resin raw material can be improved more.

  In addition, when a number average molecular weight is less than the said lower limit, there exists a possibility that the reactivity of a lignin derivative may fall. On the other hand, when the number average molecular weight exceeds the upper limit, the softening point of the lignin derivative is too high, and the meltability or solubility may be lowered.

In addition, when the lignin derivative obtained in the present invention is subjected to 1H-NMR analysis, the integral value of the peak attributed to the aromatic proton in the spectrum of the chemical shift obtained is the peak attributed to the aliphatic proton. It is preferably about 55 to 200% of the integral value, more preferably about 60 to 150%, further preferably about 65 to 100%, and particularly preferably about 70 to 80%. Thereby, the reactivity which contributes to the mechanical characteristic of the cured resin of a lignin derivative and the meltability which contributes to the impregnation property to a base material etc., or the solubility to a solvent can be highly compatible. As a result, the base material or the like can be reliably impregnated while maintaining the reactivity of the lignin derivative, so that the lignin derivative can be effectively used as a resin raw material. That is, a lignin derivative suitable for a resin raw material can be obtained. In addition, according to this invention, the lignin derivative which has such a characteristic can be manufactured efficiently and reliably.
When the ratio falls below the lower limit, a reaction site that causes a crosslinking reaction by the action of a general curing agent or a reaction site for introducing a reactive group is substituted with an aliphatic group, and Since the familiarity is deteriorated, when a lignin derivative is used as a resin raw material, the impregnation property to the base material may be lowered. On the other hand, when the ratio exceeds the upper limit, the meltability of the lignin derivative or the solubility in the solvent is lowered, and thus the appearance of the lignin resin molded body described later may be impaired.

  In addition, since aromatic protons and aliphatic protons have peaks at distant positions in the chemical shift spectrum of 1H-NMR analysis, peaks can be separated, and peak identification and integral value calculation should be performed. Can do.

  Specifically, when tetramethylsilane is used as a reference substance for analysis, generally, a peak attributed to an aromatic proton is located in the vicinity of 6 to 8 ppm. In addition, the peak attributed to the aliphatic proton is located in the vicinity of 0.5 to 5 ppm.

<Lignin secondary derivative>
As the lignin derivative, a lignin secondary derivative can be used by introducing a reactive group into the phenolic hydroxyl group of the lignin derivative. The lignin secondary derivative may be used as a mixture with the lignin derivative. The lignin secondary derivative will be described.
By mixing the lignin derivative obtained in the above step and the compound containing a reactive group, a reactive group can be introduced into the lignin derivative to produce a lignin secondary derivative.

  As a method for introducing a reactive group, for example, a method of mixing a lignin derivative and a compound containing a reactive group is used. And a lignin secondary derivative by which the reactive group was introduce | transduced into the lignin derivative can be manufactured by adding a catalyst etc. as needed after mixing.

  Specifically, when an epoxy group is introduced, the lignin derivative, epichlorohydrin, and a solvent are mixed, and a base catalyst such as sodium hydroxide is added thereto under reflux under reduced pressure to introduce the epoxy group. Secondary lignin derivatives can be prepared.

  In addition, when introducing a vinyl group, a lignin derivative, a halogen compound containing a vinyl group such as an allyl halide or a vinylbenzyl halide, and a solvent are mixed, and a base catalyst such as sodium hydroxide is added to the mixture under heating and stirring. By doing so, a lignin secondary derivative having a vinyl group introduced therein can be produced.

  In addition, when introducing an ethynyl group, a lignin derivative, a halogen compound containing an ethynyl group such as a propargyl halide or a phenylacetylene halide, and a solvent are mixed, and a base catalyst such as sodium hydroxide is added to the mixture with heating and stirring. By doing so, a lignin secondary derivative having an ethynyl group introduced therein can be produced.

  In addition, when introducing a cyanate group, a lignin derivative, a halogenated cyanate, and a solvent are mixed, and a base catalyst such as sodium hydroxide is added to this under heating and stirring, whereby a lignin secondary in which the cyanate group has been introduced. Derivatives can be produced.

  When introducing a maleimide group, a lignin derivative and parachloronitrobenzene are mixed. As a result, the maleimide group reacts with the phenolic hydroxyl group of the lignin derivative to obtain a polynitrated lignin bonded via an ether bond. Next, by reducing the polynitrated lignin, it is converted to a polyaminated lignin, and further reacted with maleic anhydride to produce a lignin secondary derivative having a maleimide group introduced.

Moreover, when introduce | transducing an isocyanate group, the hydroxyl group in a lignin derivative is converted into a carboxyl group by mixing a lignin derivative and maleic anhydride. Thereafter, the mixture is heated in the presence of diphenyl phosphate azide, whereby a lignin secondary derivative having an isocyanate group introduced therein can be produced.
A lignin secondary derivative can be produced as described above.

  The produced lignin secondary derivative is obtained by introducing a reactive group into a lignin derivative as described above. Since such a lignin secondary derivative has various reactive groups, it can be crosslinked at a high density and is useful as a resin raw material.

  The reactive group possessed by the lignin secondary derivative is a reactive atomic group, is self-reactive, and can react with two or more of the same reactive groups, or react with other functional groups. There is no particular limitation as long as it can be obtained. Specific examples include a vinyl group having a carbon-carbon unsaturated bond, an ethynyl group, and a maleimide group, as well as an epoxy group, a cyanate group, and an isocyanate group. Moreover, an epoxy group is preferably used. The lignin secondary derivative having an epoxy group is useful as a resin raw material that can replace a general epoxy resin.

<Lignin resin composition>
By using the above lignin derivative, a lignin resin composition as a resin raw material can be obtained. Here, as the lignin derivative, a part or all of the above-described lignin secondary derivative can be used.

Hereinafter, the lignin resin composition will be described.
The lignin resin composition contains the lignin derivative. The lignin resin composition can contain a crosslinking agent in addition to the lignin derivative. When the cross-linking agent is contained, a cross-linking reaction is caused by the cross-linking agent and the resin is cured, so that a resin molded article excellent in bending fracture strain and the like can be produced from the lignin resin composition.

  The cross-linking agent is not particularly limited as long as it causes a cross-linking reaction with the phenolic hydroxyl group of the lignin derivative. For example, an ortho-resole novolac epoxy resin, an epoxy resin such as a bisphenol A-type epoxy resin, hexa Urethane resins such as methylene diisocyanate and toluene diisocyanate, and compounds that can be cross-linked by electrophilic substitution reaction on aromatic rings of lignin derivatives include aldehydes such as formaldehyde, acetaldehyde and paraformaldehyde, and aldehydes such as polyoxymethylene. In addition to the source, hexamethylenetetramine, known phenolic resins such as resol type phenolic resins, known crosslinking agents, compounds that can be crosslinked by electrophilic substitution reaction on the aromatic ring of the lignin derivative, and the like. In addition, hexamethylenetetramine is preferably used from the viewpoint of reactivity and availability.

When the lignin secondary derivative is included as the lignin derivative, the cross-linking agent that causes a cross-linking reaction to the reactive group of the lignin secondary derivative is a cross-linking agent that reacts with the reactive group or a self-cross-linking property. Any crosslinking agent having a reactive group may be used.
As the crosslinking agent, when the reactive group in the lignin secondary derivative is an epoxy group, for example, a phenol resin such as a novolak type phenol resin, a lignin compound having a phenolic hydroxyl group, diethylenetriamine, m-xylylenediamine, Amine compounds such as N-aminoethylpiperazine, acid anhydrides such as phthalic anhydride, succinic anhydride, maleic anhydride, dicyandiamide, guanidines, 2-methylimidazole, 2-ethyl-4-methylimidazole, etc. A general curing agent for epoxy resin is used.
Examples of the crosslinking agent having a self-crosslinkable reactive group include imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole, 1,8-diazabicyclo (5,4,0) undecene. Anionic polymerization initiators such as -7, cationic systems such as triphenylsulfonium hexafluorophosphate, sulfonium salts such as diphenylsulfonium tetrafluoroborate, phenyldiazonium hexafluorophosphate, diazonium salts such as phenyldiazonium tetrafluoroborate A polymerization initiator etc. are mentioned, Among these, the 1 type, or 2 or more types of mixture is used. Among these, amine compounds are preferably used from the viewpoint of reactivity and the like.

  Further, when the reactive group in the lignin secondary derivative is an isocyanate group, examples of the crosslinking agent include general curing agents for isocyanate resins such as phenol resins, lignin degradation products, polyvinyl alcohol, and polyamine compounds. Among them, one or a mixture of two or more of these is used.

  When the reactive group in the lignin secondary derivative is a vinyl group, examples of the crosslinking agent include anionic polymerization initiators such as butyl lithium and sodium ethoxide, azobisisobutyronitrile (AIBN), Examples thereof include polymerization initiators of general vinyl group-containing compounds such as radical polymerization initiators such as benzoyl peroxide (BPO), and one or a mixture of two or more of these are used.

  Further, when the reactive group in the lignin secondary derivative is an ethynyl group, as a crosslinking agent, for example, a polymerization catalyst of a general ethynyl group-containing compound such as molybdenum pentachloride, tungsten pentachloride, norbornadiene rhodium chloride dimer or the like can be used. Among them, one or a mixture of two or more of these is used.

  In addition, when the reactive group in the lignin secondary derivative is a maleimide group, examples of the crosslinking agent include polymerization of general maleimide group-containing compounds such as peroxides such as BPO and the aforementioned anionic polymerization initiators. An initiator is mentioned, The mixture of 1 type, or 2 or more types of these is used.

  Further, when the reactive group in the lignin secondary derivative is a cyanate group, examples of the crosslinking agent include polymerization catalysts for general cyanate group-containing compounds such as metal catalysts such as cobalt naphthenate, and the like. Among them, one kind or a mixture of two or more kinds is used.

  In the lignin resin composition, the content of the lignin derivative or lignin secondary derivative is preferably 40 to 95 parts by weight, and more preferably 50 to 90 parts by weight. Moreover, it is preferable that content of a crosslinking agent is 5-60 weight part, and it is more preferable that it is 10-50 weight part.

  In addition to the above-mentioned components, the lignin resin composition may contain, as necessary, an alkali metal salt such as sodium methoxy and t-butoxy potassium, an alkaline earth metal salt such as calcium acetate, Na2O, and K3O2. It may contain a curing accelerator such as an alkali metal oxide, an alkaline earth metal oxide such as CaO or BaO.

  In particular, when a lignin secondary derivative having an epoxy group as a reactive group is included, for example, imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole, 1,8-diazabicyclo (5, 4,0) undecene-7, tris (dimethylaminomethyl) phenol, tertiary amines such as benzyldimethylamine, triphenylphosphine, tetra-n-butylphosphonium tetraphenylborate and the like may be contained.

Moreover, when the lignin secondary derivative which has a vinyl group, an ethynyl group, a maleimide group, a cyanate group etc. as a reactive group is included, the said polymerization initiator may be included, for example.
Furthermore, the additive mentioned later may be included as other components.

  Examples of such additives include silane coupling agents such as epoxy silane, mercapto silane, amino silane, alkyl silane, ureido silane, and vinyl silane, titanate coupling agents, aluminum coupling agents, and aluminum / zirconium coupling agents. Various coupling agents, colorants such as carbon black, bengara, polyethylene wax, higher fatty acid esters, fatty acid amides, ketones and amines, synthetic waxes such as hydrogenated oils, natural waxes such as paraffin wax and montan wax, Higher fatty acids such as stearic acid and zinc stearate and metal salts thereof, mold release agents such as paraffin, silicone oil, low stress components such as silicone rubber, antimony trioxide, aluminum hydroxide, Examples include magnesium oxide, zinc borate, zinc molybdate, flame retardants such as phosphazene, inorganic ion exchangers such as bismuth oxide hydrate, and a combination of one or more of these is used. It is done.

  When the lignin resin composition contains a release agent, the content of the release agent is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the lignin derivative or lignin secondary derivative. More preferably, it is 1 to 5 parts by weight. In addition, when the content of the release agent is less than the above, when the lignin resin composition is filled in a mold and molded, the mold release property may be insufficient, whereas the content of the release agent If the value exceeds the upper limit, the curability of the lignin resin composition may be reduced.

  Such a lignin resin composition can be obtained, for example, by uniformly mixing at least one of a lignin derivative and a lignin secondary derivative, a crosslinking agent, and other components added as necessary with a mixer. It is done. If necessary, the obtained mixture may be heated, melted and fused at a temperature lower than the temperature at which the mixture is cured using a hot plate, a kneader such as a pressure kneader, a roll, a kneader, or a twin screw extruder. Good. The specific heating temperature varies slightly depending on the composition to be selected, but is preferably about 50 to 100 ° C.

  Further, when a molded body is obtained by molding a lignin resin composition, it is preferable to prepare a molding material in which a filler is added to the lignin resin composition and to mold it using this.

  Examples of the filler include inorganic fillers such as fused silica, crystalline silica, clay, alumina, mica, and glass fiber, and organic fillers such as wood powder, pulp, pulverized cloth, and thermosetting resin cured powder. One or more of these can be used, but is not limited thereto.

  In this case, the content of the filler is preferably 10 to 900 parts by weight, and more preferably 20 to 500 parts by weight with respect to 100 parts by weight of the lignin resin composition.

  Such a molding material can be obtained, for example, by uniformly mixing a lignin resin composition, a filler, and other components added as necessary with a mixer. If necessary, the obtained mixture may be heated and mixed, kneaded, etc., and crushed after cooling to form a granular molding material.

  The obtained molding material is molded by a desired molding method, and a resin product can be produced by curing the molding material. Examples of the molding method include transfer molding, injection molding, and compression molding.

  The molding temperature is preferably about 150 to 220 ° C., and the molding time is preferably about 1 to 5 minutes. These conditions are appropriately adjusted according to the purpose.

  As mentioned above, although the lignin resin composition of this invention was demonstrated, this invention is not limited to this, For example, arbitrary components may be added to the lignin resin composition.

  Further, by impregnating a core material such as paper or fabric with a lignin resin composition, a lignin resin molded article, which will be described later, excellent in mechanical properties, durability and appearance can be produced. As the core material, for example, thin paper, craft paper, titanium paper, linter paper, paperboard, base paper for gypsum board, coated paper, art paper, sulfuric acid paper, glassine paper, parchment paper, paraffin paper, Japanese paper and various other papers, glass Fiber, asbestos fiber, potassium titanate fiber, alumina fiber, silica fiber, carbon fiber, metal fiber, inorganic fiber such as mineral fiber, synthetic resin fiber such as aramid fiber, polyester fiber, acrylic fiber, vinylon fiber or natural fiber Non-woven fabrics or woven fabrics of various fibers such as these are used, and one or more of these composites are used.

<Lignin resin molding>
Next, the lignin resin molding manufactured from the lignin resin composition of this invention is demonstrated. For example, the lignin resin molded body is produced by molding the lignin resin composition of the present invention when or after molding.

  Specifically, the lignin resin composition is produced by heating and pressing in a molding die and then curing.

  The temperature at the time of heat and pressure molding is preferably about 100 to 280 ° C, more preferably about 120 to 250 ° C. Further, the pressure is preferably about 0.5 to 20 MPa, more preferably about 1 to 10 MPa.

  The molding method is not particularly limited, and the lignin resin molded body of the present invention is formed into a molded product using a known molding method, for example, an injection molding method, a compression molding method, an extrusion molding method, a cast molding method, or the like. Can do. The form of the lignin resin molded product thus obtained may be any form, for example, an intermediate molded product before the molding material is made into a final molded product. Also good.

  The lignin resin molded body thus obtained is applied to applications such as semiconductor parts, aircraft parts, automobile parts, industrial machine parts, electronic parts, electrical parts, mechanical parts, and the like.

  Although the present invention has been described above, the present invention is not limited to this. For example, in the method for producing a lignin derivative and the method for producing a lignin secondary derivative, any desired process may be added.

Next, specific examples of the present invention will be described.
Example 1
<Preparation of lignin derivative>
200 parts by weight of phenol (molecular weight 94) and 367 parts by weight of ion-exchanged water are introduced into a 10 L autoclave to 100 parts by weight of cedar wood powder that has been pulverized and sieved to 500 μm, and the cedar wood powder and the mixed solvent are stirred. After fully acclimatizing, the temperature was increased while stirring at 150 rpm, and the mixture was treated at 9 MPa and 300 ° C. for 1 hour to decompose cedar wood flour. The pressure was adjusted by pressurization by blowing nitrogen gas.
Next, the treated product was filtered to separate it into a solid residue and a filtrate. The obtained filtrate was separated into an aqueous solution layer mainly containing water and a phenol solution layer mainly containing phenols. The aqueous solution layer was removed with a dropper, and a phenol solution layer containing a lignin derivative was recovered.
The obtained phenol solution layer was distilled under reduced pressure at 150 ° C. and 10 hPa to distill off the phenol, which was a solvent, to obtain a lignin derivative with a yield of 60% based on cedar wood flour.

≪Evaluation of gel time of lignin derivative≫
10 g of hexamethylenetetramine was added to 100 g of the obtained lignin derivative, and the gel time (gelation time) at 175 ° C. was measured for this sample according to the method specified in JIS K 6910.
The evaluation criteria for gel time (seconds) are as follows.
◎: 30 seconds to less than 60 seconds ○: 20 seconds to less than 30 seconds, or 60 seconds to less than 90 seconds △: 10 seconds to less than 20 seconds, or 90 seconds to less than 120 seconds ×: less than 10 seconds, or 120 seconds or more The obtained results are shown in Table 1.

<< 1H-NMR analysis of lignin derivative >>
When the obtained lignin derivative was subjected to 1H-NMR analysis, in the spectrum of chemical shift using tetramethylsilane as a reference substance of 0 ppm, a plurality of peaks attributed to aromatic protons at 6 to 8 ppm were 0.5 A plurality of peaks attributed to aliphatic protons were observed at ˜5 ppm.
Therefore, for each detected peak, the integrated value of the plurality of peaks attributed to the aromatic proton was set to 1, and the integrated value of the plurality of peaks attributed to the aliphatic proton was 1.45. That is, the integrated value of the plurality of peaks attributed to the aromatic proton was 70% of the integrated value of the plurality of peaks attributed to the aliphatic proton.
The obtained results are shown in Table 1.

≪Measurement of number average molecular weight of lignin derivative≫
The number average molecular weight of the obtained lignin derivative was measured by gel permeation chromatography in terms of polystyrene using tetrahydrofuran as an eluent. The number average molecular weight (Mn) of the obtained lignin derivative was 450.
The obtained results are shown in Table 1.

<Manufacture of lignin resin composition>
Next, 10 parts by mass of hexamethylenetetramine was added to 100 parts by mass of the obtained lignin derivative at room temperature to obtain a lignin resin composition.

<Manufacture of lignin resin molding>
Next, the resin composition obtained above was applied to kraft paper (basis weight 135 g / m 2) with a dip coater device so that the resin impregnation rate was 55% by mass (ratio to the whole prepreg), and then And dried at 100 ° C. for 10 minutes to obtain a prepreg. Eight prepregs thus produced were stacked and subjected to heat and pressure molding at 200 ° C. and 5 MPa for 10 minutes. This obtained the lignin resin molding (laminated board) with an average thickness of 1.6 mm.

<< Evaluation of resin impregnation >>
In the production of the lignin resin molded product, the impregnation property of the resin composition was evaluated according to the following evaluation criteria.
○: Permeated to the back side of the kraft paper ×: Insufficient penetration of the back side of the kraft paper The results obtained are shown in Table 1.

≪Evaluation of strain at bending fracture≫
The obtained laminate was subjected to a bending test until it broke according to the method specified in JIS-C6481. And the ratio (strain at the time of bending fracture | rupture) of the change of the dimension after a test with respect to the dimension before a test was evaluated according to the following evaluation criteria.
○: The strain at the time of bending fracture is 1% or more.
X: The strain at the time of bending fracture is less than 1%.
The obtained results are shown in Table 1.

(Example 2)
Example 1 was repeated except that the treatment temperature was changed to 230 ° C. and the treatment pressure was changed to 3 MPa.

(Example 3)
The same procedure as in Example 1 was conducted except that the biomass was changed to beech, the treatment temperature was changed to 260 ° C., and the treatment pressure was changed to 4 MPa.

(Example 4)
Example 1 was repeated except that the treatment time was changed to 15 minutes.

(Example 5)
Except for changing biomass to beech, changing solvent water to 267 parts by weight, changing solvent phenol to 300 parts by weight, changing processing temperature to 260 ° C, and changing processing time to 30 minutes Same as Example 1.

(Example 6)
The same procedure as in Example 1 was carried out except that the biomass was changed to Miso bamboo, the processing temperature was changed to 230 ° C., and the processing pressure was changed to 3 MPa.

(Example 7)
Example 1 was repeated except that the solvent water was changed to 267 parts by weight, the solvent phenol was changed to 300 parts by weight, the processing temperature was changed to 260 ° C., and the processing pressure was changed to 4 MPa.

(Example 8)
Example 1 was repeated except that the total amount of phenol as a solvent was changed to p-cresol (molecular weight 108).

(Comparative Example 1)
The same procedure as in Example 1 was conducted except that the total amount of phenol as a solvent was changed to methanol, the processing temperature was changed to 230 ° C., and the processing pressure was changed to 5 MPa.

(Comparative Example 2)
Example 1 was repeated except that the solvent water was changed to 567 parts by weight, the solvent phenol was changed to 0 parts by weight, the processing pressure was changed to 8 MPa, and the processing time was changed to 120 minutes.

In each Example, the lignin derivative was easily obtained from biomass with a high yield. The obtained lignin derivative had excellent gel time.
Moreover, it was recognized that the laminated board obtained by each Example is excellent in resin impregnation property and distortion at the time of bending fracture.

On the other hand, in each comparative example, the lignin derivative from biomass contained a low yield or inferior gel time.
Moreover, the laminated board obtained by each comparative example contained what was inferior to resin impregnation property or distortion at the time of bending fracture.

Claims (9)

A method for producing a lignin derivative obtained by decomposing biomass,
A decomposition step in which biomass is placed in the presence of a mixed solvent containing water and phenols, and these are decomposed under high temperature and high pressure to obtain decomposition products;
A recovery step of obtaining a phenol solution containing a lignin derivative from the decomposition product obtained by the decomposition step;
A distillation step of distilling off phenols from the phenol solution obtained by the recovery step;
A process for producing a lignin derivative characterized by comprising:   The method for producing a lignin derivative according to claim 1, wherein the weight of the phenols in the decomposition step is 100 to 2000 parts by weight with respect to 100 parts by weight of biomass.   The method for producing a lignin derivative according to claim 1 or 2, wherein the content of phenol in the mixed solvent containing water and phenol in the decomposition step is 10 to 75% by weight.   The method for producing a lignin derivative according to any one of claims 1 to 3, wherein the molecular weight of phenol in the mixed solvent containing water and phenol in the decomposition step is 90 or more and 300 or less.   The method for producing a lignin derivative according to any one of claims 1 to 4, wherein the decomposition step is a decomposition treatment at a treatment temperature of 150 to 350 ° C and a treatment pressure of 1 to 40 MPa.   The method for producing a lignin derivative according to any one of claims 1 to 5, wherein the decomposition step is a decomposition treatment in a treatment time of 5 to 480 minutes or less.   A lignin derivative obtained by the method for producing a lignin derivative according to any one of claims 1 to 6.   A lignin resin composition comprising the lignin derivative according to claim 7.   A lignin resin molded article obtained by curing the lignin resin composition according to claim 8.