JP2015048361A - Lignin resin composition, resin molded article, prepreg, and molding material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition comprising a lignin derivative having a high hot-melt property and high reactivity with an epoxy or isocyanate, and to provide a resin molded article comprising a lignin derivative, which shows a fast molding cycle and a high glass transition temperature.SOLUTION: The resin composition comprises a lignin derivative and a crosslinking agent, and contains a lignin derivative having at least one phenolic structure in the structure thereof as the lignin derivative and a crosslinking agent having an epoxy group or an isocyanate group as the crosslinking agent. The lignin derivative is a decomposed produce of a lignin component included in biomass, to which a phenolic structure is added.

Description

  The present invention relates to a lignin resin composition and a resin molded body.

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.
Common woody main components are cellulose, hemicellulose and lignin. Among these, lignin contained at a ratio of about 30% has a structure containing abundant aromatic rings, phenolic hydroxyl groups, and alcoholic hydroxyl groups, and is therefore being studied for use as a resin raw material.

  Patent Document 1 describes a method in which lignin contained at a ratio of about 30% is used as a resin raw material.

Further, 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.
However, the lignin derivative produced by the method as described above is difficult to be thermoformed because of low meltability and solubility. Also, since a large amount of inorganic acid remains, for example, in the case of sulfuric acid, problems such as discoloration may occur at the time of thermoforming, and there is a problem that it is too costly to purify to a level where there is no practical problem. .

JP 2001-261839 A

  An object of the present invention is to provide a resin composition containing a lignin derivative which is rich in heat melting property and highly reactive to epoxy or isocyanate. Another object of the present invention is to provide a resin molded article containing a lignin derivative, having a fast molding cycle and a high glass transition point.

The present invention is as follows.
(1) A lignin resin composition containing a lignin derivative and a crosslinking agent, the lignin derivative containing one or more phenol structures in the structure, and a crosslinking agent containing an epoxy group or an isocyanate group, and containing sulfuric acid Is less than 2% by mass, a lignin resin composition.
(2) The lignin resin composition according to (1), wherein the lignin derivative contains lignin obtained by decomposing biomass and having a phenol structure added thereto.
(3) The lignin resin composition according to (1) or (2), wherein the lignin derivative has a softening point of 200 ° C. or lower.
(4) The lignin derivative has a number average molecular weight of 300 or more and 3000 or less. (1) to (3) The lignin resin composition according to any one of (1) to (5) other than sulfuric acid contained in the lignin resin composition The lignin resin composition according to (1), wherein the inorganic acid is less than 2% by mass.
(6) A resin molded body (7) obtained by curing the lignin resin composition according to any one of (1) to (5), or any one of (1) to (5) A prepreg obtained by using the lignin resin composition described.
(8) A molding material obtained by using the lignin resin composition according to any one of (1) to (5) and a filler.

  According to the present invention, a lignin component contained in biomass is decomposed, a phenol structure is introduced, and a curing agent is contained, so that the resin composition can be provided with high heat melting property. Moreover, since it becomes the lignin derivative which is excellent in reactivity and excellent in heat melting property, a fast molding cycle is possible, and a resin molded product having a high glass transition point can be provided.

As a result of intensive studies to achieve the above problems, the present inventors have decomposed the lignin component contained in the biomass, introduced a phenol structure, and contained a curing agent, so that the reactivity is high. In addition to being able to provide a lignin derivative with excellent heat melting properties, the lignin component was decomposed during subcritical processing, while preventing recombination between lignins, and by adding a phenol structure, the above properties were excellent. The inventors have found a production method capable of obtaining a lignin derivative in a high yield, and have completed the present invention.
Hereinafter, preferred embodiments of the lignin resin composition, resin molded body, prepreg and molding material of the present invention will be described.

<Lignin resin composition>
The lignin resin composition of the present invention contains a lignin derivative obtained by decomposing biomass, further adds a phenol structure, and has high reactivity to an epoxy or isocyanate crosslinking agent.
The addition of a phenol structure to lignin can be carried out by an addition reaction of a compound having a phenol structure (hereinafter referred to as a phenol structure) to a lignin derivative obtained by decomposing biomass, but as a simple method, When biomass is decomposed, the biomass is placed in the presence of a mixed solvent containing water and a phenol structure, and these are decomposed under high temperature and high pressure to obtain lignin added with a phenol structure in the decomposition step to obtain a decomposed product. It can be easily manufactured.

<Lignin derivative>
First, the lignin derivative will be described. Lignin, together with cellulose and hemicellulose, is a major component that forms the skeleton of plants and is one of the most abundant substances in nature. A lignin derivative is a compound having a phenol derivative as a unit structure, and this unit structure has a chemically and biologically stable carbon-carbon bond or carbon-oxygen-carbon bond. It is difficult to undergo manual decomposition. For this reason, a lignin derivative is useful as a resin raw material.

  The lignin derivative used in the present invention is obtained by decomposing biomass. Biomass is a plant or a processed product of a plant, and these are formed by capturing and fixing carbon dioxide in the atmosphere in the process of photosynthesis, and thus contribute to the suppression of the increase in carbon dioxide in the atmosphere. For this reason, it can contribute to suppression of global warming by utilizing biomass industrially. In addition, lignin is usually present as lignocellulose having a bond with cellulose in the biomass, but may be present as lignin in the biomass by performing a saccharification treatment or a hydrolysis treatment.

  Examples of a treatment method for decomposing biomass to obtain a lignin derivative include, for example, a method of treating a plant or a processed plant product with a chemical, a method of hydrolyzing, a steam explosion method, a supercritical water treatment method, a subcritical water treatment method, Examples thereof include a mechanical treatment method and a pulp production method. In the present invention, from the viewpoint of environmental load, a hydrolysis treatment method, a steam explosion method, a supercritical water treatment method, and a subcritical water treatment method are preferable. From the viewpoint of the purity of the obtained lignin derivative, the steam explosion method and the subcritical water treatment method are more preferable.

As an example, biomass can be placed in the presence of a mixed solvent containing water and a phenol structure, and these can be decomposed under high temperature and pressure to obtain a decomposed product. By this step, the biomass can be decomposed into lignin derivatives. Details of the biomass decomposition step will be described later.
In addition to the lignin derivative obtained by decomposition in the present invention, a cellulose decomposition product and a hemicellulose decomposition product may be included.

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. From conifers, mainly guaiacylpropane structures, from broadleaf trees, mainly guaiacylpropane structures and syringylpropane structures, and from herbs, mainly guaiacylpropane structures, syringylpropane structures, and 4-hydroxy Each phenylpropane structure is extracted.

  The lignin derivative in the present invention obtained as described above preferably has a polystyrene-equivalent number average molecular weight of 300 to 3000, more preferably 350 to 2500, as measured by gel permeation chromatography. Such a lignin derivative having a number average molecular weight has a higher balance between reactivity (curability) and meltability or solubility. Therefore, a resin composition having a high degree of compatibility between solvent resistance and moldability after curing can be obtained.

  An example of a method for measuring the molecular weight by the gel permeation chromatography will be described.

  The measurement sample is prepared by dissolving the lignin derivative in the present invention in a solvent. The solvent used at this time is not particularly limited as long as it can dissolve the lignin derivative, but from the viewpoint of measurement accuracy of gel permeation chromatography, for example, tetrahydrofuran is preferable.

Next, “TSKgelGMMHXL (manufactured by Tosoh)” which is an organic general-purpose column packed with a styrene polymer filler in the GPC system “HLC-8320GPC (manufactured by Tosoh)”,
And “G2000HXL (manufactured by Tosoh)” are connected in series.

  200 μL of the above measurement sample is injected into this GPC system, and the eluent tetrahydrofuran is developed at 1.0 mL / min at 40 ° C., and is retained using differential refractive index (RI) and ultraviolet absorbance (UV). Measure time. The number average molecular weight of the lignin derivative can be calculated from a calibration curve showing the relationship between the retention time and molecular weight of standard polystyrene prepared separately.

  The molecular weight of the standard polystyrene used for preparing the calibration curve is not particularly limited. For example, the number average molecular weight is 427,000, 190,000, 96,400, 37,900, 18,100. Standard polystyrene (manufactured by Tosoh) of 10,200, 5,970, 2,630, 1,050 and 500 can be used.

The softening point of the lignin derivative of the present invention is preferably 200 ° C. or lower.
If a lower limit is provided, the temperature is preferably 70 ° C. or higher, more preferably 80 ° C. or higher, and further preferably 90 ° C. or higher. When the softening point exceeds 200 ° C., the heat melting property and fluidity are poor, and molding may not be possible. On the other hand, if the softening point exceeds the above upper limit value, there are too many hot melts and fluidity, so that a lot of burrs are generated at the time of molding, and the loss at the time of manufacture may be large. On the other hand, if the lower limit value is not reached, the handling property of the resin is deteriorated, which is disadvantageous during molding. The softening point can be changed by controlling the average molecular weight of the lignin derivative according to the decomposition temperature of the biomass and the type of phenol structure added to the lignin derivative.

  The method for measuring the softening point was a ring-and-ball softening point tester (ASP-MG2 type manufactured by Meltech Co., Ltd.) according to JIS K2207.

The sulfuric acid contained in the lignin derivative obtained as described above is preferably less than 2% by mass, more preferably less than 0.5% by mass, and even more preferably less than 0.1% by mass. is there. If the upper limit is exceeded, sulfur atoms are included, which leads to a decrease in the electrical properties of the resin composition, and also adversely affects discoloration during molding, long-term reliability of molded products, and corrosivity when in contact with metals. May have an effect.
Similarly, inorganic acids other than sulfuric acid are preferably suppressed to less than 2% by mass, more preferably less than 0.5% by mass, and even more preferably less than 0.1% by mass. Specifically, the inorganic acid is a strong acid such as hydrochloric acid, nitric acid, or hydrofluoric acid.
Moreover, although the inorganic acid containing a sulfuric acid may exist as an inorganic acid ion as an inorganic acid, it is necessary to suppress both to less than 2 mass%.

<Method for producing resin composition>
Next, an example of a method for producing the resin composition of the present invention will be described.
The method for producing the resin composition of the present invention includes: [1] a decomposition step in which biomass is placed in the presence of a mixed solvent containing water and a phenol structure, and these are decomposed under high temperature and high pressure to obtain a decomposed product. And [2] a recovery step in which the lignin derivative is removed from the decomposition product obtained in the decomposition step and the phenol structure is distilled off from the phenol structure solution, or a step in which the lignin derivative is recovered from an insoluble matter in the decomposition product. In detail, [2-a] when the lignin derivative is contained in the solid component in the treated product, the solid component is treated with a polar solvent, and the insoluble matter and the solution separated from the polar solvent are separated and / or Or [2-b] when the solvent in the treated product contains a lignin derivative, the solvent (solution) containing the lignin derivative is separated from the solid component.

Next, [3] is a step of drying the solution of [2] and recovering the solute (lignin derivative).
Moreover, you may have the process of mixing the collect | recovered solute and other resin components as needed, and obtaining a resin composition. Hereinafter, each process will be described sequentially.

Step [1] Decomposition Step A decomposition step in which biomass is placed in the presence of a mixed solvent containing water and a phenol structure and these are decomposed under high temperature and high pressure to obtain a decomposition treatment 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 a phenol structure.

  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 a solvent used in the decomposition step in the present invention, a mixed solvent containing water and a phenol structure 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 structure 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, naphthol, etc., and one or a mixture of two or more of these Is used.

  The molecular weight of the phenol structure is preferably 90 or more and 400 or less, and more preferably 93 or more and 350 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 structure solution in the recovery step described later. On the other hand, a phenol polymer such as novolak may be decomposed and added, so that it can be used even when the molecular weight exceeds the above range.

  The weight of the phenol structure in the decomposition step is not limited, but is preferably 10 to 2000 parts by weight, more preferably 25 to 1000 parts by weight, and more preferably 50 to 300 parts by weight with respect to 100 parts by weight of biomass. Most preferably. When the weight of the phenol is in the above range, the strength of the cured product is improved by introducing a phenol structure, and the yield of the lignin derivative can be improved.

Further, the content of the phenol structure of the mixed solvent containing water and the phenol structure in the decomposition step is not limited, but is preferably 1 to 75% by weight, and more preferably 15 to 70% by weight. If the content of the phenol structure is less than 1%, the effect of adding the phenol structure may be difficult depending on the amount of the solvent. On the other hand, if the content of the phenol structure exceeds 75%, there is a practical problem. No, but it can be too expensive. If the content of the phenol structure is 15% or more and 75% or less, in the mixed solution containing water and the phenol structure, the solution layer mainly containing water and the solution layer mainly containing the phenol structure are separated. Therefore, the lignin derivative can be easily recovered by recovering the phenol structure solution layer.
Furthermore, when the weight of the phenol structure in the decomposition step is in 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 a phenol structure, the active species generated in the natural lignin by the cleavage reaction of benzyl aryl ether present in the natural lignin reacts with the phenol structure, The lignin derivative having a reduced molecular weight can be obtained. For this reason, the yield of the said lignin derivative can also be improved.

  The mixed solvent may contain other solvents in addition to water and the phenol structure. The content of the other solvent in the mixed solvent is less than each of water and the phenol structure, and is preferably 10% by mass or less, 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, recovery of the phenol structure solution containing the lignin derivative in the separation step described later can be facilitated without impairing the decomposition of 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 addition, depending on the biomass used as the raw material, not only lignin derivatives but also cellulose, hemicellulose, and other decomposition products and reaction products thereof can be obtained.

  The generation of the high temperature and high pressure environment is not particularly limited as long as it is a container that can withstand high temperature and pressure, but a pressure vessel such as an autoclave can be used. In addition, as the pressure vessel, those equipped with heating means and stirring means are preferably used, and mechanical such as stirring the biomass by mechanical or turbulent flow at high temperature and high pressure, or blasting by pressure release, etc. It is preferred that energy be applied. 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 nitrogen gas or argon gas into the container.

As for the conditions in the decomposition treatment, the treatment temperature is preferably 150 to 400 ° C, more preferably 180 to 350 ° C, and further preferably 220 to 320 ° C. When the treatment temperature is within the above range, the molecular weight of the lignin derivative obtained after decomposition can be optimized. Thereby, the moldability of a resin composition and the solvent resistance after hardening can be made compatible more highly.

  The processing time in the decomposition process may be an appropriate processing time depending on the apparatus used for the processing. For example, if the apparatus to be used is an autoclave, it is preferably 480 minutes or less, more preferably 15 to 360 minutes. If the treatment time is 480 minutes or more, the heat energy cost is increased, and the production cost is increased. There is no problem even if the treatment time is shorter than 15 minutes, but depending on the apparatus, heat transfer may be insufficient and biomass decomposition may be insufficient.

  Furthermore, the pressure in the decomposition treatment is preferably 1 to 40 MPa, more preferably 1.5 to 25 MPa, and further preferably 3 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.

  In addition, it is preferable to perform the process which fully stirs biomass and the said solvent as a pre-process of a decomposition | disassembly process, and adjusts both. Thereby, the decomposition of biomass can be particularly optimized. The stirring temperature is preferably about 0 to 150 ° C, and more preferably about 10 to 130 ° C. Further, the stirring time is preferably about 1 to 120 minutes, more preferably 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 inorganic acid contained in the lignin derivative obtained as described above needs to be suppressed to less than 2% by mass. If the above upper limit is exceeded, depending on the type of inorganic acid, it may lead to a decrease in the electrical properties of the resin composition, discoloration during molding, long-term reliability of the molded product, and corrosivity during contact with metal. This is because it may adversely affect
Specifically, the inorganic acid is a strong acid such as sulfuric acid, hydrochloric acid, nitric acid, or hydrofluoric acid. In particular, since sulfuric acid contains a sulfur atom, it is preferably less than 2% by mass, more preferably less than 0.5% by mass, and still more preferably less than 0.1% by mass.
In addition, although an inorganic acid may exist as an inorganic acid ion as an inorganic acid, it is necessary to suppress both to less than 2 mass%.

  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 treatment is preferably used in a subcritical or supercritical state (condition). A solvent in a subcritical or supercritical state can accelerate the biomass decomposition treatment without a special additive component such as a catalyst. For this reason, it becomes possible to decompose biomass in a short time without using a complicated separation process, and it is possible to reduce the manufacturing cost of the lignin derivative and simplify the manufacturing process.
As an example, the critical temperature of water is about 374 ° C., and the critical pressure is about 22.1 MPa.

Process [2]
The recovery process obtained by distilling off the lignin derivative from the decomposition product and the phenol structure from the phenol structure solution, or the process of recovering from the insoluble matter of the decomposition product will be described.
As described above, in the step [2], when the lignin derivative is contained in the solid component in the [2-a] processed product, the solid component is treated with a polar solvent to separate the insoluble matter from the polar solvent from the solution. The step and / or [2-b] when the solvent in the treated product contains a lignin derivative, the solvent (solution) containing the lignin derivative is separated from the solid component. Each step will be described in detail.
[2-a]
The processed material in the pressure vessel is filtered. Then, the filtrate is removed, and the solid component separated by filtration is recovered. And the collect | recovered solid component is immersed in the solvent in which lignin is soluble. The solid component immersed in the solvent in which lignin is soluble is further filtered to separate into a component soluble in the solvent (soluble component) and a component insoluble in the solvent (insoluble component).

  As the solvent in which lignin is soluble, various polar solvents are used, and particularly those containing lower alcohols such as methanol and ethanol, and ketones such as acetone and methyl ethyl ketone are preferably used. By using these polar solvents, it is possible to separate and extract the lignin derivative dissolved in the polar solvent and the lignin derivative insoluble in the polar solvent from the recovered solid component.

  The immersion time is not particularly limited, but is preferably about 1 to 48 hours, and more preferably about 2 to 30 hours. Moreover, it is also possible to heat at the boiling point or less of a solvent at the time of immersion.

[2-b]
The processed material in the pressure vessel is filtered. Then, the solid component is removed, and the filtrate (dissolved solution) separated by filtration is recovered. In addition, when a solid component is a small amount, it does not need to filter.

  When a large amount of filtrate remains in the solid component, it may be washed with the various polar solvents. By using these polar solvents, the filtrate containing a large amount of lignin derivative can be completely separated from the solid component and recovered.

[3]
Next, the solvent in which lignin is soluble is distilled off from the filtrate (dissolved solution) obtained in the separation step, and the dried solute (lignin derivative) is recovered.

In particular, the filtrate (dissolved solution) obtained in [2-b] contains two or more kinds of solvents.

When the lignin derivative is uniformly dispersed in two or more kinds of solvents, it is preferable to distill off the solvents collectively.
When the filtrate (dissolved solution) is phase-separated into a layer containing a lignin derivative and a layer not containing a lignin derivative, only the solution containing the lignin derivative is separated by separating the layer not containing the lignin derivative. The solvent is preferably distilled off after the recovery.

  Examples of a method for recovering only the solution containing the lignin derivative include a method for separating a supernatant solution and a method for separating using a separatory funnel, but are not limited thereto.

Examples of the method for distilling off the solvent include, but are not limited to, a method of drying under reduced pressure (vacuum drying) and a method of reprecipitation of a lignin derivative using a good solvent and a poor solvent.

In the vacuum drying method, the vacuum drying temperature is preferably set to a temperature according to the solvent to be distilled off. The solvent used for the decomposition treatment has a high boiling point and is 210 ° C. or lower. Therefore, the vacuum drying temperature is preferably 40 to 250 ° C, more preferably 50 to 230 ° C.
The time for drying under reduced pressure is not particularly limited, but is preferably about 0.5 to 48 hours, and more preferably about 1 to 24 hours.
The effective vacuum drying temperature and time vary depending on the scale to be dried. What is necessary is just to select optimal temperature and time by the vacuum dryer to be used.

  The pressure in the vacuum drying is preferably from 0.1 to 60 kPa, more preferably from 0.5 to 50 kPa.

  In the method of reprecipitation of the lignin derivative, examples of the good solvent include methanol, acetone, and tetrahydrofuran, and examples of the poor solvent include diethyl ether, toluene, hexane, and the like, but are not limited thereto.

(Description of lignin secondary derivatives)
When obtaining a resin composition containing a lignin secondary derivative, the reactive functional group is introduced into the lignin derivative by bringing the extracted lignin derivative into contact with a compound containing the reactive functional group. May be.

  As a method for introducing a reactive functional group, for example, a method of mixing a lignin derivative and a compound containing a reactive functional group is used, and after mixing, a catalyst or the like may be added as necessary.

  Specifically, when introducing an epoxy group, a lignin derivative, epichlorohydrin, and a solvent are mixed, and a base catalyst such as sodium hydroxide may be added thereto under reflux under reduced pressure.

  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. do it.

  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. do it.

  Moreover, when introduce | transducing a cyanate group, a lignin derivative, halogenated cyanate, and a solvent are mixed, and a base catalyst, such as sodium hydroxide, may be added to this under heating and stirring.

  When introducing a maleimide group, a lignin derivative and parachloronitrobenzene are mixed. As a result, a chloro group reacts with the phenolic hydroxyl group of the lignin derivative to obtain a polynitrated lignin bonded via an ether bond. Subsequently, polynitrated lignin is reduced to be converted to polyaminated lignin, and further reacted with maleic anhydride to introduce a maleimide group.

  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 isocyanate group is introduced by heating the mixture in the presence of diphenyl phosphate azide.

(Crosslinking agent)
The resin composition of the present invention uses a crosslinking agent when it is molded by various molding methods.
Since the crosslinking agent used in the resin composition of the present invention can mainly be crosslinked with the phenol skeleton of the lignin derivative, it can be used as long as it is a crosslinking agent used in a phenol novolac. It is preferable to contain at least one crosslinking agent selected from:

  Examples of the epoxy compound of the crosslinking agent include monomers, oligomers and polymers having an epoxy group in one molecule.

  The number of epoxy groups contained in the epoxy compound of the crosslinking agent is not particularly limited as long as it has one or more. From the viewpoint of improving the solvent resistance of the resin composition or the resin molded product, 2 It is preferable to have at least one.

  Specific examples of the epoxy compound of the crosslinking agent include, for example, biphenyl type epoxy resins, stilbene type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins and other bisphenol type epoxy resins, and triphenolmethane type epoxy resins. Novolaks such as alkyl-modified triphenolmethane type epoxy resin, dicyclopentadiene-modified phenol type epoxy resin, triazine nucleus-containing epoxy resin, phenol aralkyl type epoxy resin, naphthol type epoxy resin, phenol novolac type epoxy resin, cresol novolak type epoxy resin Aromatic epoxy compounds such as epoxy resin, polyethylene glycol type epoxy resin, polypropylene glycol type epoxy resin, hexanediol type epoxy resin Xy resin, trimethylolpropane type epoxy resin, pentaerythritol type epoxy resin, glycerol type epoxy resin, polyglycerol type epoxy resin, sorbitol type epoxy resin, epoxy resin derived from soybean oil, epoxy resin derived from linseed oil, epoxy resin derived from rice bran oil Examples thereof include epoxy compounds having no aromaticity such as resins. One or a mixture of two or more of these may be used. Among these, bisphenol A type epoxy resins and cresol novolac type epoxy resins are preferred because of excellent heat resistance such as glass transition temperature. Among these, trimethylolpropane type epoxy resin, pentaerythritol type epoxy resin, glycerol type epoxy resin, polyglycerol type epoxy resin, sorbitol type epoxy resin, and linseed oil-derived epoxy resin are preferable in terms of excellent solvent resistance. .

  Further, as the epoxy compound of the crosslinking agent, a compound obtained by epoxidizing a non-petroleum-derived compound can also be used. When such a compound is used as the epoxy compound of the crosslinking agent, it also has a high degree of natural origin, and therefore is preferable from the viewpoint of excellent environmental compatibility.

  The isocyanate compound of the crosslinking agent refers to all monomers, oligomers and polymers having an isocyanate group in one molecule.

  The number of isocyanate groups contained in the isocyanate compound of the crosslinking agent is not particularly limited as long as it has one or more. From the viewpoint of improving the solvent resistance of the resin composition or the resin molded product, 2 It is preferable to have at least one.

Specifically, for example, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4-4′-diisocyanate, dicyclohexylmethane-2-4′-diisocyanate, norbornenemethane diisocyanate, 2,4-tolylene diisocyanate, 2,6- Examples include tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylene diisocyanate, diphenylmethane-4-4′-diisocyanate, diphenylmethane-2-4′-diisocyanate, and 3-methyldiphenylmethane diisocyanate. One or a mixture of two or more of these may be used.

Among the specific examples of the isocyanate compound, diphenylmethane-4-4′-diisocyanate and diphenylmethane-2-4′-diisocyanate are preferable from the viewpoint of solvent resistance, and hexamethylene diisocyanate is more preferable from the viewpoint of ensuring moldability.
The upper limit of the functional group equivalent of the crosslinking agent is preferably 400 from the viewpoint of action as a crosslinking agent, and more preferably 250 from the viewpoint of crosslinking density. When the functional group equivalent exceeds the upper limit, the appearance may be impaired. Moreover, the lower limit value of the functional group equivalent of the crosslinking agent is not particularly limited, but is preferably 50 or more practically.

(Other cross-linking agents)
Moreover, the resin composition of this invention can use the following crosslinking agents other than an epoxy compound and an isocyanate compound.

[Z in Formula (7) is any one of a melamine residue, a urea residue, a glycolyl residue, an imidazolidinone residue, and an aromatic ring residue. Moreover, m represents the integer of 2-14. R is independently an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. However, -CH 2 _OR, the nitrogen atom of the melamine residues, the nitrogen atom of the primary amino groups of the urea residues, the nitrogen atom of the secondary amino group of the glycolyl residues, the secondary amino group of the imidazolidinone residues It is directly bonded to either the nitrogen atom or the carbon atom of the aromatic ring residue. ]

  The resole resin, furan resin, and compound represented by (7) contained in the other crosslinking agent have self-curing properties and can form a co-crosslinked structure with the lignin derivative. Therefore, a cured product obtained by molding and curing such a resin composition is composed of a lignin derivative and a resole resin, a furan resin, and a compound represented by (7) contained in the other crosslinking agent. Good compatibility and high homogeneity. Therefore, the blending ratio can be optimized from the viewpoint of achieving both the moldability of the resin composition and the resistance to distortion of the cured product, and a resin molded article excellent in dimensional accuracy and resistance to distortion can be obtained.

  Furthermore, since the resole resin, furan resin, and the compound represented by (7) contained in the above other crosslinking agents generate mild volatile components during the crosslinking reaction, the volatile components are released to the outside of the cured product. It is possible to suppress problems such as blisters and cracks that occur as a result. As a result, a resin molded body having an excellent appearance can be obtained.

  In addition, the furan resin contained in the said other crosslinking agent and the compound represented by (7) contribute to the improvement of the moldability of a resin composition. This is because the melting point of the other cross-linking agent is low, the viscosity of the molding material is lowered during heating, and the other cross-linking agent is relatively slowly cross-linking, and gradually undergoes a cross-linking reaction when heated. This is thought to be advancing.

The obtained resin composition includes prepregs, laminates, and molding materials, which will be described later, wood building materials, wood decorative boards, additives to thermoplastic resins, additives and reinforcing materials for rubber compositions, friction materials, It can be used as a thermosetting resin for applications such as a mold resin.
In addition to the crosslinking agent, the resin composition of the present application may contain a catalyst, a filler, various additives, and the like described later.

(catalyst)
The molding material of the present invention may contain a catalyst. As the catalyst, various catalysts can be used as long as they can promote curing and crosslinking of the resin composition.

  When the crosslinking agent is an epoxy compound, examples of the catalyst include imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole, 1,8-diazabicyclo (5,4,0) undecene- 7,1,5-diazabicyclo (4.3.0) nonane-5-ene, tris (dimethylaminomethyl) phenol, tertiary amines such as benzyldimethylamine, triphenylphosphine, tetra-n-butylphosphonium tetra Examples include general catalysts for epoxy resins such as phenyl borate.

When the crosslinking agent is an isocyanate compound, examples of the catalyst include an organotin compound, a carboxylic acid tin salt, a carboxylic acid lead salt, and a carboxylic acid bismuth salt.
In the case of adding the catalyst, the amount of the catalyst added is preferably 0.01 to 5.0 parts by weight with respect to 100 parts by weight of the total content of the resin composition, the crosslinking agent and the other crosslinking agent. 1 to 2.5 parts by weight is more preferable.

Further, as described later, when a reactive functional group is introduced into the lignin derivative, a catalyst corresponding to the type of the reactive functional group may be appropriately selected and used.
Specifically, when the reactive functional group is an epoxy group, examples of the catalyst include imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole, 1,8-diazabicyclo (5, 4,0) undecene-7,1,5-diazabicyclo (4.3.0) nonane-5-ene, tris (dimethylaminomethyl) phenol, tertiary amines such as benzyldimethylamine, triphenylphosphine, tetra Common catalysts for epoxy resins such as -n-butylphosphonium tetraphenylborate are listed.

  In addition, when the reactive functional group is an isocyanate group, examples of the curing agent include general isocyanate resin catalysts such as polyvinyl alcohol and polyamine compounds, and one or more of these may be used. A mixture is used.

  When the reactive functional group is a vinyl group, examples of the curing agent include anionic polymerization initiators such as butyl lithium and sodium ethoxide, azobisisobutyronitrile (AIBN), benzoyl peroxide (BPO). The polymerization initiator of a general vinyl group-containing compound such as a radical polymerization initiator such as) is used, and one or a mixture of two or more of these is used.

  Further, when the reactive functional group is an ethynyl group, examples of the curing agent include polymerization catalysts for general ethynyl group-containing compounds such as molybdenum pentachloride, tungsten pentachloride, norbornadiene rhodium chloride dimer, and the like. One of them or a mixture of two or more of them is used.

  When the reactive functional group is a maleimide group, examples of the curing agent include peroxides such as BPO and polymerization initiators of general maleimide group-containing compounds such as the anionic polymerization initiator described above. One or a mixture of two or more of these is used.

  Further, when the reactive functional group is a cyanate group, the curing includes, for example, a polymerization catalyst of a general cyanate group-containing compound such as a metal catalyst such as cobalt naphthenate, and one of these or A mixture of two or more is used.

  When a catalyst is added to promote the reaction of the reactive functional group introduced into the lignin derivative, the addition amount of the catalyst is 100 parts by weight with respect to the total content of the resin composition, the crosslinking agent, and the other crosslinking agent. 0.01-5.0 weight part is preferable and 0.1-2.5 weight part is further more preferable.

(filler)
Examples of fillers include talc, calcined clay, unfired clay, mica, silicates such as glass, oxides such as titanium oxide and alumina, fused silica (fused spherical silica, fused crushed silica), crystalline silica Silicon compounds like, carbonates like calcium carbonate, magnesium carbonate, hydrotalcite, hydroxides like aluminum hydroxide, magnesium hydroxide, calcium hydroxide, like barium sulfate, calcium sulfate, calcium sulfite Sulfate or sulfite, zinc borate, barium metaborate, aluminum borate, calcium borate, borate such as sodium borate, powder such as nitride such as aluminum nitride, boron nitride, silicon nitride, glass In addition to inorganic fillers such as fiber, carbon fiber, etc., wood powder, pulp pulverized powder, cloth砕粉, cured thermosetting resin powder, organic fillers, and the like, such as aramid fibers. Among these, as the filler, among metal oxide, metal hydroxide, metal nitride, silicon oxide, glass fiber, carbon fiber, aramid fiber, wood powder, pulp pulverized powder, and cloth pulverized powder, The thing containing at least 1 type is mentioned, Although 1 or more types of these can be used, it is not limited to these. These fillers can lower the expansion coefficient of the molding material produced from the resin composition.

  In this case, the content of the filler is preferably 10 to 900 parts by weight, more preferably 20 to 500 parts by weight, and 100 to 450 parts by weight with respect to 100 parts by weight of the resin composition. Is more preferable. When the content rate of a filler is less than the said lower limit, there exists a possibility that the expansion coefficient of the resin molding manufactured from the resin composition cannot fully be reduced. On the other hand, when the content rate of the filler exceeds the upper limit, the moldability of the resin composition may be deteriorated because the ratio of the filler is too large.

  Moreover, it is preferable that the average particle diameter of a filler is about 0.1-500 micrometers, and it is more preferable that it is about 0.2-300 micrometers. When the average particle diameter of the filler is within the above range, the resin molded body produced from the resin composition is highly compatible with a low expansion coefficient and excellent moldability. The average particle size of the filler refers to the particle size of the powder distributed in 50% of the cumulative volume in the particle size distribution of the filler.

In addition, examples of the shape of the filler include, but are not particularly limited to, flake shape, dendritic shape, spherical shape, and fibrous shape.
In addition, when a filler is fibrous, it is preferable that it is a fiber diameter of 0.5-100 micrometers and fiber length about 1-50 mm.

(Other additives)
In addition to the above-mentioned components, the resin composition of the present invention may contain an alkali metal salt such as sodium methoxy, t-butoxy potassium, an alkaline earth metal salt such as calcium acetate, NA ₂ O, K ₂ , if necessary. A curing accelerator such as an alkali metal oxide such as O, or an alkaline earth metal oxide such as CAO or BAO may be included.
Furthermore, various additives may be included as necessary.

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

  Moreover, when a molding material contains a mold release agent, it is preferable that content of a mold release agent is 0.01-10 mass parts with respect to 100 mass parts of resin compositions, and is 0.1-5 mass parts. More preferably. In addition, when the content of the release agent is less than the above, when the resin composition or the crosslinking agent is filled in the mold and molded, the mold release property may be insufficient. When content exceeds the said upper limit, there exists a possibility that the sclerosis | hardenability of a resin composition and a crosslinking agent may fall.

<Prepreg>
The prepreg of the present invention is obtained by impregnating or coating the resin composition of the present invention on a core material such as paper or fabric and forming a B-stage. The prepreg of the present invention can be produced by impregnating and coating the above thermosetting resin composition on a sheet-like reinforcing base material and semi-curing (B-stage) by air drying or heating.
With this prepreg, a laminate described later, which is 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.
Usually, the prepreg of the present invention can be obtained by heating and drying at a temperature of 20 to 200 ° C. for 0.1 to 20 hours and semi-curing (B-stage).

<Laminated plate>
The laminate of the present invention is obtained by laminate molding using the aforementioned resin composition or prepreg. For example, it can be manufactured by stacking 1 to 20 prepregs and laminate-molding them with a configuration in which a metal foil such as copper and aluminum is disposed on one or both sides thereof. The metal foil is not particularly limited as long as it is used in a laminated plate.
The molding conditions can be applied to a laminate for an electrical insulating material and a multilayer board, for example, using a single stage press, a multistage press, a multistage vacuum press, a continuous molding machine, etc., at a temperature of 100 to 250 ° C., a pressure of 0.2. It can shape | mold in the range of 10-10 MPa and heating time 0.1-5 hours.
Further, the prepreg of the present invention and the inner layer wiring board can be combined and laminated to produce a multilayer board.

<Molding material>
Next, the molding material containing the resin composition of the present invention will be described. The molding material is a material for obtaining a molded product.

  When a molding material containing the resin composition of the present invention is molded to obtain a molded product, a molding material to which a catalyst, a latent catalyst, a filler and other additives are added in addition to the resin composition is prepared and used. It is preferable to mold.

  The molding material containing the resin composition of the present invention is preferably in the form of a lump from the viewpoint of improving workability, and more preferably in the form of a pellet or plate from the viewpoint of enhancing the molding stability of the molding material containing the resin composition.

  Specifically, the molded article is manufactured by heating and press-molding a molding material containing the resin composition in a molding die and then curing the molding material.

  Although there is no restriction | limiting in particular in the method of preparing a molding material, The following procedures are shown as an example. First, the lignin derivative and other resin components are mixed in an arbitrary method and order. As needed, the catalyst, latent catalyst, filler, and various additives are mixed in any manner and order. Thereby, a molding material is prepared.

  Moreover, when mixing, using a kneading machine such as a hot plate, a pressure kneader, a roll, a kneader, or a twin screw extruder, the mixture is heated and melt-kneaded at a temperature lower than the temperature at which the mixture is cured. Although the specific heating temperature at the time of heating is a little different depending on the composition to be selected, it is preferably about 50 to 130 ° C. A granular resin composition is obtained by pulverizing the cooled mixture.

  Moreover, when preparing a resin composition, you may make it add an organic solvent as needed. Examples of the organic solvent include, but are not limited to, methanol, ethanol, propanol, butanol, methyl cellosolve, acetone, methyl cellosolve, methyl ethyl ketone, methyl isobutyl ketone, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, quinoline, cyclopentanone, xylene, m-cresol, chloroform and the like can be mentioned, and one or a mixture of two or more of these can be used.

In addition, you may make it add a diluent as needed. Examples of the diluent include organic solvents having a relatively high boiling point such as butyl cellosolve, carbitol, butyl cellosolve acetate, carbitol acetate, ethylene glycol diethyl ether, and α-terpineol.
Furthermore, you may mix the other additive mentioned above.

  The temperature at the time of heat and pressure molding is preferably about 100 to 280 ° C, more preferably about 120 to 250 ° C. Moreover, it is preferable that a pressure is about 0.5-20 MPa, and it is more preferable that it is about 1-30 MPa. Moreover, it can be heat-molded into a molded article in about 1 to 10 minutes. These molding pressure, temperature and time are appropriately adjusted according to the purpose.

  The molding material obtained is applied to uses such as semiconductor parts, aircraft parts, automobile parts, industrial machine parts, electronic parts, electrical parts, mechanical parts, rubber products, and the like.

  The molding method is not particularly limited, and the molding material of the present invention can be formed into a molded product using a known molding method such as an injection molding method, a compression molding method, an extrusion molding method, a cast molding method, or the like. . The form of the 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 or a final molded product. .

The molding material is heated to cure the lignin derivative by crosslinking with one or more of the other crosslinking agents and one of the other crosslinking agents, but the condensation reaction accompanying the dealcoholization reaction or dehydration reaction. Alternatively, it is considered that the crosslinking agent and the crosslinking reaction point of the lignin derivative are crosslinked by an addition reaction.
Further, when the lignin derivative is methylolated, a dehydration condensation reaction occurs, and the other crosslinking agent and the methylol group are crosslinked, and the other crosslinking agent and the lignin derivative are self-condensed.

  Although the present invention has been described above, the present invention is not limited to this. For example, an optional component may be added to the resin composition.

(Example 1)
<Preparation of lignin derivative>
200 parts by weight of phenol and 367 parts by weight of ion-exchanged water are introduced into a 10-liter autoclave to 100 parts by weight of cedar wood powder that has been crushed and sieved to a 500 μm sieve, and the cedar wood powder and the mixed solvent are stirred and thoroughly mixed. Then, the temperature was increased while stirring at 150 rpm, and the mixture was treated at 9 MPa and 300 ° C. for 60 minutes 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 liquid phase after separation is phase-separated into a solution layer mainly containing water and a solution layer mainly containing phenol. The upper aqueous solution layer is removed using a dropper, and a phenol structure solution layer containing a lignin derivative is removed. It was collected.
The phenol solution layer was distilled under reduced pressure at 150 ° C. and 10 hPa using an organic synthesizer, thereby distilling off the phenol as a solvent to obtain a lignin derivative with a yield of 78% based on cedar wood flour.

  Further, the molecular weight of the lignin derivative obtained above was measured by gel permeation chromatography in terms of polystyrene using tetrahydrofuran as an eluent, and the number average molecular weight (Mn) was 420.

<Manufacture of lignin resin molding>
A lignin resin, a crosslinking agent, and a catalyst were combined at a mixing ratio as shown in Table 1, and a total of 25% by weight and a silica filler (average particle size of 17 μm manufactured by Denki Kagaku Kogyo Co., Ltd.) was mixed by 75% by weight. 80 ° C., 50 rpm. Kneaded at 175 ° C. for 5 min. Was subjected to compression molding under the conditions of 175 ° C. for 4 hours to obtain a test piece for bending strength, which was a resin molded body having a width of 10 mm, a length of 100 mm, and a height of 4 mm.

<Manufacture of lignin resin laminate>
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. As a result, a lignin resin laminate having an average thickness of 1.6 mm was obtained.

(Examples 2 to 10)
Except for changing the type of biomass, solvent in decomposition treatment, temperature, pressure and time as shown in Table 1, respectively, in the same manner as in Example 1, to obtain a lignin derivative, a cellulose derivative and a hemicellulose derivative, Using the lignin derivative obtained in Step 1, a molded body and a laminate were obtained.
In all the examples, the content of inorganic acids other than sulfuric acid was 0.1% by mass or less.

(Comparative Example 1)
The biomass was decomposed by changing the solvent, temperature, pressure and time in the decomposition treatment as shown in Table 1. Subsequently, the decomposition treatment product was filtered and separated into a solid component and a filtrate. The separated solid component is extracted with acetone, filtered, and the filtrate is dried, so that the lignin derivative is extracted with acetone obtained at a yield of 15%, and the solid component obtained by filtration is a lignin derivative. , A mixture of a cellulose derivative and a hemicellulose derivative and could not be sufficiently separated.

(Comparative Example 2)
The decomposition treatment product obtained by the decomposition treatment was filtered to separate it into a solid component and a filtrate. The separated filtrate was dried to obtain a mixture of lignin derivative and hemicellulose derivative. The obtained mixture was further washed with hot water to obtain a lignin derivative with a yield of 15%. On the other hand, the solid formation was a mixture of a lignin derivative, a cellulose derivative and a hemicellulose derivative and could not be sufficiently separated.

(Comparative Example 3)
An extraction step was performed by stirring a treated solution obtained by mixing 517 parts by weight of a 70% sulfuric acid solution and 50 parts by weight of p-cresol with 100 parts by weight of a cedar wood powder that had been pulverized and sieved to 500 μm, at 45 ° C. for 60 minutes. It was. Next, it is filtered and solid-liquid separated. The solid phase obtained is washed with water of about 4 times by weight, and after solid-liquid separation, it is washed with 10% aqueous sodium hydroxide solution of about 4 times by weight. It was summed up. Finally, the obtained solid phase was naturally dried to obtain a lignin derivative with a yield of 13%.

  The number average molecular weight (Mn) of each lignin derivative obtained in each example and each comparative example was measured and shown in Table 1.

Further, for each lignin derivative obtained in each example and each comparative example, a spectrum of chemical shift by 1H-NMR analysis was obtained and assigned to an aromatic proton with respect to an integrated value of a plurality of peaks assigned to an aliphatic proton. Table 1 shows the ratio of integrated values of a plurality of peaks.
Compared with the comparative example, the ratio of the integral value of the example is high. This has shown that many phenol structures are contained in the structure of the lignin derivative of an Example, and has confirmed the effect of this invention.

2. Evaluation of lignin derivatives (inorganic acid content measurement method (ionic impurity test))
Place 1.0 g of sample and ultrapure water in the extraction container and seal it,
The sample was extracted with hot water at 125 ° C. for 20 hours, and after centrifugation, the supernatant was taken as a test solution.
Ion chromatography analyzer (Dionex ICS-2000, DX-320 ion chromatograph)
Quarantine and standard solution were introduced into the sample, and each ion concentration was determined by the calibration curve method and converted to the concentration in the sample.

(Softening point)
As a method for measuring the softening point, a ring and ball softening point tester (ASP-MG2 type manufactured by Meltec Co., Ltd.) was used according to JIS K2207.

(Hydroxyl equivalent)
About the lignin derivative obtained by the said method, the hydroxyl equivalent was measured. The hydroxyl equivalent was determined by the following method. In a stoppered Erlenmeyer flask, 4.0 g of a mixed solution of acetic anhydride / pyridine (1/3 volume ratio) and 1.0 g of a sample were dissolved. After maintaining this solution at 60 ° C. for 3 hours, 1 ml of pure water was added. The solution thus obtained was titrated with a 0.1 mol / L NaOH aqueous solution with pH = 10 as the end point, and the hydroxyl group equivalent was determined from the following formula. The measurement results are shown in Table 1.
Hydroxyl equivalent (g / eq) = 1000 * W / (((TB * f * S / SB)-(T * f)) * N)
The meaning of each symbol in the formula is as follows.
W: Sample weight (g)
TB: Blank titration (ml)
SB: Amount of blank acetic anhydride-pyridine mixture (g)
T: Titration volume with sample (ml)
S: Amount of acetic anhydride-pyridine mixed solution added with sample (g)
f: Factor of standard aqueous sodium hydroxide solution
N: Normality of sodium hydroxide standard aqueous solution

3. Evaluation of curing reactivity of lignin derivatives (Method of adjusting curing reactivity measurement sample)
As shown in Table 1, 0.6 parts by mass of the catalyst was added to 100 parts by mass of the resin and the crosslinking agent adjusted at a functional group equivalent ratio of 1: 1, and the sample was prepared by pulverization and mixing in a mortar.

(DSC peak temperature)
The temperature was measured by DSC (DSC6220 manufactured by SII) under a nitrogen atmosphere at 10 ° C./min, and the temperature at the top of the reaction peak was calculated.

(Geltime)
Using the obtained sample, the gel time (gelation time) at 175 ° C. was measured in accordance with the method defined in JIS K 6910.

(175 ° C shear viscoelasticity: 1.0 × 10 ⁶ Pa arrival time)
Using the obtained sample, shear viscoelasticity was measured at 175 ° C., 1 Hz, and Φ25 mm using MCR301 (manufactured by Anton Paar). After starting measurement, storage elastic modulus is 1.0 × 1
The time (minutes) at which 0 ⁶ Pa was reached was measured.

4). Evaluation of molded bodies and laminates (bending strength of molded bodies)
The bending strength was determined according to JIS K6911.

(Moldability of molded product, appearance)
The bending property of a 10 mm wide, 100 mm long, 4 mm high molded piece formed by compression molding was visually evaluated for the presence or absence of blistering, and the appearance was visually evaluated for the surface color.

(Evaluation of resin impregnation properties of laminates)
In the production of the laminate, the impregnation property of the resin composition was evaluated according to the following evaluation criteria.
Good: Penetrating to the back side of the kraft paper Poor: Insufficient penetration of the back side of the kraft paper The results obtained are shown in Table 1.

(Evaluation of the appearance of the laminate)
The presence / absence of unevenness and unevenness of the lignin resin laminate subjected to heat and pressure molding were visually evaluated.

As shown in Table 1, the examples made it possible to obtain good resin characteristics.

Claims (8)

A lignin resin composition comprising a lignin derivative and a crosslinking agent,
A lignin derivative containing one or more phenolic structures in the structure;
A lignin resin composition comprising a crosslinking agent containing an epoxy group or an isocyanate group, and having a sulfuric acid content of less than 2% by mass.   The lignin resin composition according to claim 1, wherein the lignin derivative contains lignin obtained by decomposing biomass and having a phenol structure added thereto.   The lignin resin composition according to claim 1, wherein the lignin derivative has a softening point of 200 ° C. or less.   The lignin resin composition according to any one of claims 1 to 3, wherein the lignin derivative has a number average molecular weight of 300 or more and 3000 or less.   The lignin resin composition according to claim 1, wherein an inorganic acid other than sulfuric acid contained in the lignin resin composition is less than 2% by mass.   A resin molded article obtained by curing the lignin resin composition according to any one of claims 1 to 5.   A prepreg obtained by using the lignin resin composition according to any one of claims 1 to 5. A molding material obtained by using the lignin resin composition according to any one of claims 1 to 5 and a filler.