JP2020050815A - Production method of resin material comprising phenol-modified lignin resin, and production method of structure body by using the same - Google Patents

Abstract

To provide a production method of a resin material comprising a phenol-modified lignin resin, which can improve mechanical properties of a molding material.SOLUTION: The production method of a resin material comprising a phenol-modified lignin resin comprises: a reaction step of reacting in a vessel a raw material comprising phenols and aldehydes to obtain a reaction mixture; and an addition step of adding, after the reaction step, lignins to the reaction liquid in the vessel in a heated state.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a resin material containing a phenol-modified lignin resin, and a method for producing a structure using the same.

  Until now, various developments have been made in a method for producing a phenol-modified lignin resin. As this type of technology, for example, a technology described in Patent Document 1 is known. Patent Document 1 describes a procedure of adding formaldehyde after phenol reaction with lignin (paragraph 0041 of Patent Document 1).

JP 2013-199561 A

  However, as a result of the study by the present inventors, in the method for producing a phenol-modified lignin resin described in Patent Document 1, there is room for improvement in mechanical properties of a molding material using the obtained phenol-modified lignin resin. It has been found.

  The present inventor further studied and found that when a resin material containing a phenol-modified lignin resin was used as a molding material, the mechanical properties of the molding material could be controlled by appropriately adjusting the production process of the phenol-modified lignin resin. I found it. Based on these findings, we conducted further research and found that after reacting a raw material containing phenols and aldehydes to obtain a reaction solution, lignins were added to the reaction solution in a heated state, and the mechanical properties of the molding material were reduced. The inventors have found that a resin material containing a phenol-modified lignin resin capable of improving the physical properties can be obtained, and have completed the present invention.

According to the present invention,
A reaction step of reacting a raw material containing phenols and aldehydes in a container to obtain a reaction solution;
A method for producing a resin material containing a phenol-modified lignin resin, comprising: an addition step of adding lignin to the reaction solution in a heated state in the container after the reaction step.

According to the present invention,
A resin material obtained by the above-described method for producing a resin material,
A curing agent,
And a method for producing a phenol-modified lignin resin composition, comprising the step of:

According to the present invention,
There is provided a method for producing a structure including a cured product of a phenol-modified lignin resin composition, the method including a step of molding the phenol-modified lignin resin composition obtained by the method for producing a phenol-modified lignin resin composition.

  According to the present invention, a method for producing a resin material containing a phenol-modified lignin resin capable of improving the mechanical properties of a molding material, a method for producing a phenol-modified lignin resin composition using the obtained resin material, and A method for manufacturing a structure including a cured product is provided.

The outline of the method for manufacturing the resin material of the present embodiment will be described.
The method for producing a resin material containing a phenol-modified lignin resin of the present embodiment comprises a reaction step of reacting a raw material containing phenols and aldehydes in a container to obtain a reaction solution; And adding an lignin to the reaction solution in a heated state.

  According to the findings of the present inventors, it has been found that the phenol-modified lignin resin (resin material) obtained by such a production method can enhance the mechanical properties of a cured product of a molding material.

  The resin material containing the phenol-modified lignin resin obtained by the production method of the present embodiment can be suitably used for a molding material.

  Hereinafter, the method for producing the resin material containing the phenol-modified lignin resin of the present embodiment will be described in detail.

  The method for producing a resin material includes a reaction step of obtaining a reaction solution, and an addition step of adding lignins to the reaction solution. Each step will be described.

  The above reaction step includes a step of reacting a raw material containing phenols and aldehydes to obtain a reaction solution. A raw material containing phenols and aldehydes can react under acidic conditions. As the acidic condition, a known acid such as an organic acid or an inorganic acid can be used as a catalyst.

<Phenols>
In the present disclosure, phenols include phenol, phenol derivatives, and combinations thereof. The phenol derivative only needs to have a phenol skeleton, and may have an arbitrary substituent on the benzene ring. Examples of the substituent include a hydroxy group; a lower alkyl group such as a methyl group and an ethyl group; a halogen atom such as fluorine, chlorine, bromine and iodine; an amino group; a nitro group; Examples of phenols include phenol, catechol, resorcinol, hydroquinone, o-cresol, m-cresol, p-cresol, o-fluorophenol, m-fluorophenol, p-fluorophenol, o-chlorophenol, m-chlorophenol, p-chlorophenol, o-bromophenol, m-bromophenol, p-bromophenol, o-iodophenol, m-iodophenol, p-iodophenol, o-aminophenol, m-aminophenol, p-aminophenol, Examples include o-nitrophenol, m-nitrophenol, p-nitrophenol, 2,4-dinitrophenol, 2,4,6-trinitrophenol, salicylic acid, p-hydroxybenzoic acid, and combinations thereof. In the present disclosure, one or more of these can be used. Examples of the alkylphenols include those having 2 to 18 carbon atoms. If the number of carbon atoms is within the above-mentioned range, the alkyl chain may have a branched chain or may have an unsaturated bond. In addition, any of ortho, meta and para-substituted alkyl phenol compounds can be used for the substitution position of the alkyl chain. For example, ethyl phenol, propyl phenol, isopropyl phenol, butyl phenol, secondary butyl phenol, tertiary butyl phenol, amyl phenol, tertiary amino phenol, hexyl phenol, heptyl phenol, octyl phenol, tertiary octyl phenol, nonyl phenol, tertiary nonyl phenol, decyl phenol, Undecyl phenol, dodecyl phenol, tridecyl phenol, tetradecyl phenol, pentadecyl phenol, cardanol, curdle, urushiol, hexadecyl phenol, methyl curdole, heptadecyl phenol, raccol, thiol and octadecyl phenol. As the vegetable oil, cashew nut shell liquid (cashew oil), urushi extract and the like can be used.
Among these, phenols can include one or more selected from the group consisting of phenol, cresol, xylenol, alkylphenol and bisphenol, and from the viewpoint of inexpensiveness, phenol, cresol, butylphenol, and bisphenol A can be used. .

<Aldehydes>
In the present disclosure, aldehydes include formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, polyoxymethylene, chloral, hexamethylenetetramine, furfural, glyoxal, n-butyraldehyde, caproaldehyde, allylaldehyde, benzaldehyde, croton Examples thereof include aldehyde, acrolein, tetraoxymethylene, phenylacetaldehyde, o-tolualdehyde, salicylaldehyde, and para-xylene dimethyl ether. Preferably, formaldehyde, paraformaldehyde, trioxane, polyoxymethylene, acetaldehyde, p-xylene dimethyl ether and a combination thereof are exemplified. These can be used alone or in combination of two or more.
Among them, formalin or paraformaldehyde can be used from the viewpoints of productivity and low cost.

<Acid>
Any acid can be used as long as it can be used as a catalyst for the reaction, and organic acids, inorganic acids and combinations thereof can be used. Examples of the organic acid include acetic acid, formic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, benzoic acid, salicylic acid, sulfonic acid, phenolsulfonic acid, and paratoluenesulfonic acid. Examples of the inorganic acid include hydrochloric acid, sulfuric acid, sulfate ester, phosphoric acid, phosphate ester, and the like.

  In the above reaction step, the molar ratio of the aldehyde (F) to the phenol (P) (F / P molar ratio) may be, for example, 0.4 to 1.0 mol of the aldehyde per 1 mol of the phenol. Well, preferably 0.6 to 0.9 mol. By setting the aldehydes in the above range, the amount of unreacted phenol can be reduced, and the yield can be increased.

  The reaction temperature in the above reaction step may be, for example, 60 ° C to 120 ° C, and preferably 80 ° C to 100 ° C. This allows the reaction to proceed efficiently and sufficiently. The reaction time is not particularly limited, and may be appropriately determined according to the type of starting materials, the molar ratio of the starting materials, the amount and type of the catalyst used, and the reaction conditions.

  The raw material used in the above reaction step may contain components other than phenols and aldehydes, and may contain, for example, lignins. The raw material components may be added all at once, or may be added in multiple portions.

  The above reaction step is preferably carried out without a solvent, but an organic solvent or water may be used as a solvent. Examples of the organic solvent include, for example, alcohols, ketones, esters, ethers, and hydrocarbons. Examples of the alcohols include methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol, octanol, and ethylene. Glycols, diethylene glycol, triethylene glycol, propylene glycol, glycerin and the like; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone and cyclohexanone; and esters as methyl acetate, ethyl acetate, propyl acetate and acetic acid Butyl, methoxybutyl acetate, amyl acetate, methyl lactate, ethyl lactate, butyl lactate, etc., and ethers such as propyl ether, dioxane, methyl cellosolve, ethyl cellulose Solve, propyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, methyl carbitol, ethyl carbitol, butyl carbitol, methyl cellosolve acetate, ethyl cellosolve acetate, propyl Cellosolve acetate, butyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, and hydrocarbons such as toluene, xylene, pentane, hexane, cyclohexane, and heptane Emissions, octane, decane, solvent naphtha, industrial gasoline, petroleum ether, petroleum benzine, and a ligroin. These may be used alone or in combination of two or more.

  After the above reaction step and before the addition step, a dehydration step of performing dehydration on the reaction solution in the container may be performed. As a dehydration method, dehydration under reduced pressure may be used, but dehydration under normal pressure may be used. For example, the degree of vacuum during the dehydration under reduced pressure may be, for example, 110 torr or less, and more preferably 80 torr or less.

  Subsequently, the addition step after the reaction step includes a step of adding lignins to the reaction solution in a heated state in the container.

Here, when a phenol resin, which is a reaction product of a phenol and an aldehyde, and a lignin are simply mixed without heating, a large amount of a solvent is required, which may lower the batch yield. For this reason, the cost of the solvent is high, and the number of steps for dissolving the raw material and removing the solvent is required, which may lower the productivity.
On the other hand, according to the present embodiment, since lignins are added to the reaction solution in a heated state, a large amount of solvent is not required, and the productivity can be improved. Also, the yield of the resin is improved.

Here, when aldehydes are added to phenols after addition of lignins, the viscosity of the reaction product increases and dehydration becomes difficult, so that the process time may be prolonged. Also, a large amount of unreacted phenols may remain.
On the other hand, in the present embodiment, the process time can be shortened and the resin yield can be increased as compared with the case where the aldehydes are added after the addition of the lignins. Although the detailed mechanism is unknown, it is considered that the production method of the present embodiment can suppress the viscosity in the reaction solution from becoming excessively high.

  The manufacturing method of the present embodiment can be configured so as not to include a step of lowering the temperature in the container to a room temperature of 25 ° C. between the reaction step and the addition step. That is, in the manufacturing method of the present embodiment, the state where the heating is performed from the reaction step to the addition step can be maintained.

  Such a production method of the present embodiment is not only excellent in productivity but also excellent in mechanical properties as compared with the case where a solid novolak-type phenol resin and lignin are melt-mixed, and a resin material for a molding material having excellent mechanical properties. Can be realized. Although the detailed mechanism is unknown, according to the production method of the present embodiment, the dispersibility of lignins in the reaction solution can be increased as compared with the case of melt-mixing, so that the molding material has excellent mechanical properties. It is considered that the following resin material is obtained.

  In the addition step, lignins can be added to a reaction solution containing unreacted phenols. That is, lignins can be added to the reaction solution containing at least the unreacted phenols, phenols and aldehydes derived from the raw materials remaining in the reaction step.

<Lignin and lignin derivatives (lignins)>
In the present disclosure, lignins include those containing one or more selected from the group consisting of lignin and lignin derivatives.
Lignin, together with cellulose and hemicellulose, is a major component that forms the structure of plants and is one of the most abundant aromatic compounds in nature. Examples of lignin include kraft lignin, lignin sulfonic acid, soda lignin, pulp lignin such as soda-anthraquinone lignin; organosolv lignin; explosive lignin; lignophenol; phenolized lignin. The origin of lignin is not particularly limited, and includes wood and herbs including lignin and a woody part is formed, conifers such as cedar, pine and hinoki, broadleaf trees such as beech, birch, oak and zelkova, rice, wheat, Grains (grasses) such as corn and bamboo.

  In the present disclosure, “lignin derivative” refers to a compound having a unit structure constituting lignin or a structure similar to the unit structure constituting lignin. The lignin derivative has 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 or biological degradation. For these reasons, lignin derivatives are considered useful as resin raw materials.

  The lignin derivatives include guaiacylpropane (ferulic acid) represented by the following formula (A) of the following formula (1), syringylpropane (sinapic acid) represented by the following formula (B), and the following formula (C): 4-hydroxyphenylpropane (coumaric acid) and the like. The composition of the lignin derivative differs depending on the biomass used as the raw material. Lignin derivatives containing a guaiacylpropane structure are mainly extracted from conifers. Lignin derivatives containing a guaiacylpropane structure and a syringylpropane structure are mainly extracted from hardwoods. Lignin derivatives containing a guaiacylpropane structure, a syringylpropane structure and a 4-hydroxyphenylpropane structure are mainly extracted from herbs.

  As the lignin derivative, one obtained by decomposing biomass is preferable. Since biomass captures and immobilizes atmospheric carbon dioxide during the process of photosynthesis, biomass contributes to suppressing an increase in atmospheric carbon dioxide. Can be suppressed. Examples of biomass include lignocellulosic biomass. Examples of the lignocellulosic biomass include lignin-containing plant leaves, bark, branches, and wood, and processed products thereof. Examples of plants containing lignin include the above-described hardwoods, conifers, and grasses.

  Biomass decomposition methods include a chemical treatment method, a hydrolysis treatment method, a steam explosion method, a supercritical water treatment method, a subcritical water treatment method, a mechanical treatment method, a cresol sulfate method, and a pulp production method. No. From the viewpoint of environmental load, a steam explosion method, a subcritical water treatment method, and a mechanical treatment method are preferable. From the viewpoint of cost, a pulp production method is preferable. From the viewpoint of cost, it is preferable to use a by-product of biomass utilization. The lignin derivative can be prepared by subjecting biomass to a decomposition treatment in the presence of a solvent at 150 to 400 ° C and 1 to 40 MPa for 8 hours or less. In addition, the lignin derivative can be prepared by a method disclosed in JP-A-2009-08320, JP-A-2012-201828, and the like.

  Examples of the lignin derivative include those obtained by decomposing lignocellulose in which lignin, cellulose, and hemicellulose are combined. The lignin derivative may include a lignin decomposition product, a cellulose decomposition product, a hemicellulose decomposition product, and the like, which are mainly composed of a compound having a lignin skeleton.

  The lignin derivative preferably has many reaction sites where the curing agent acts by the electrophilic substitution reaction to the aromatic ring, and the less steric hindrance near the reaction site is more excellent in reactivity, the aromatic compound containing a phenolic hydroxyl group is preferred. It is preferable that at least one of the ortho position and the para position of the ring is unsubstituted, and lignin derived from conifers or herbs containing many guaiacyl nuclei or 4-hydroxyphenyl nucleus structures as aromatic units of lignin is preferable. As the lignin derivative, those disclosed in JP-A-2009-08320 and JP-A-2012-201828 can be used.

  The lignin derivative may have a functional group (secondary lignin derivative) in addition to the above basic structure.

  The functional group of the lignin secondary derivative is not particularly limited. For example, a functional group in which two or more same functional groups can react with each other or a functional group which can react with another functional group is preferable. Specific examples include an epoxy group, a methylol group, a vinyl group having a carbon-carbon unsaturated bond, an ethynyl group, a maleimide group, a cyanate group, and an isocyanate group. Of these, a lignin derivative having a methylol group introduced (methylated) is preferably used. In such a lignin secondary derivative, self-crosslinking occurs due to a self-condensation reaction between methylol groups, and the lignin secondary derivative is more crosslinked to an alkoxymethyl group or a hydroxyl group in the following crosslinking agent. As a result, a cured product having a particularly homogeneous and rigid skeleton and excellent in solvent resistance can be obtained.

  Further, the lignin derivative in the present disclosure may have a carboxyl group. When the compound has a carboxyl group, it may be crosslinked with a crosslinking agent described below, and the crosslinking point can be increased to increase the crosslinking density. Further, it may act as a catalyst for the crosslinking agent, and can promote the crosslinking reaction between the lignin derivative and the crosslinking agent, so that it has excellent solvent resistance and curing speed.

When the lignin derivative has a carboxyl group, the carboxyl group can be confirmed by the presence or absence of absorption of a peak at 172 to 174 ppm when subjected to ¹³ C-NMR analysis belonging to the carboxyl group. it can.

  The production method of the present embodiment can include, after the addition step, a removal step of removing phenols remaining in the reaction solution in the container. As the removal step, a step of removing unreacted monomers (for example, unreacted phenols) by a usual demonomerization step can be used.

  In the production method of the present embodiment, the reaction step and the addition step may be performed continuously, but may include other steps in between. During the process, the addition step may be performed one or more times.

  The reaction product in the container obtained in the above steps is taken out, and a resin material containing a phenol-modified lignin resin is obtained. In the above reaction step, by selecting an appropriate F / P molar ratio under acidic conditions, the phenol-modified lignin resin may have a structural unit derived from a novolak-type phenol resin.

The lignin modification rate of the phenol-modified lignin resin is, for example, 10% to 50%, preferably 12% to 45%, and more preferably 15% to 35%.
In the present specification, “to” indicates that an upper limit and a lower limit are included unless otherwise specified.

  The resin material containing the phenol-modified lignin resin is suitably used for a molding material. By using this resin material, it is possible to enhance the mechanical properties of the molded product such as strength and elastic modulus.

  The phenol-modified lignin resin composition of the present embodiment includes a resin material containing a phenol-modified lignin resin and a curing agent. This phenol-modified lignin resin composition can be used as a resin composition for forming a molded article.

  The method for producing the phenol-modified lignin resin composition includes a step of mixing the resin material obtained by the method for producing a resin material with a curing agent.

  As the curing agent, for example, an amine-based curing agent can be used. As the amine-based curing agent, specifically, hexamethylenetetramine, hexamethoxymethylolmelamine, or the like can be used. As the amine-based curing agent, for example, hexamethylenetetramine is preferably used.

  The content of the curing agent is, for example, 7 parts by weight to 30 parts by weight, more preferably 10 parts by weight to 25 parts by weight, based on 100 parts by weight of the phenol-modified lignin resin. By setting it within the above numerical range, good curability can be obtained.

  The method for producing the phenol-modified lignin resin composition may include a step of further mixing a filler. That is, the phenol-modified lignin resin composition can include a resin material containing a phenol-modified lignin resin, a curing agent, and a filler.

Examples of the filler include a fiber base material, an organic filler, and an inorganic filler.
The fibrous base material is a fibrous filler whose shape is fibrous. The organic filler and the inorganic filler may be either a granular filler or a plate-like filler, respectively. The plate-like filler is a filler whose shape is plate-like. The granular filler is a filler having a shape other than a fibrous or plate-like shape including an irregular shape. These may be used alone or in combination of two or more.

  As the granular filler, for example, a granular inorganic filler can be used, and glass beads, glass powder, calcium carbonate, talc, silica, aluminum hydroxide, clay, mica, and the like can be used.

Examples of the fibrous filler include glass fiber, carbon fiber, asbestos fiber, metal fiber, wollastonite, attapulgite, sepiolite, rock wool, aluminum borate whisker, potassium titanate fiber, calcium carbonate whisker, and titanium oxide whisker. And fibrous inorganic fillers such as ceramic fibers; aramid fibers, polyimide fibers, and fibrous organic fillers such as poly (paraphenylenebenzobisoxazole fibers), which may be used alone or as two kinds. These may be used in combination.
In the present embodiment, the phenol-modified lignin resin composition may include glass fibers.

  Further, as the plate-like filler, granular filler, for example, talc, kaolin clay, calcium carbonate, zinc oxide, calcium silicate hydrate, mica, glass flake, glass powder, magnesium carbonate, silica, titanium oxide, Alumina, aluminum hydroxide, magnesium hydroxide, barium sulfate, calcium sulfate, calcium sulfite, zinc borate, barium metaborate, aluminum borate, calcium borate, sodium borate, aluminum nitride, boron nitride, silicon nitride, the above fibers And the like.

  The content of the filler is, for example, 120 parts by weight to 500 parts by weight, preferably 130 parts by weight to 400 parts by weight, more preferably 150 parts by weight to 300 parts by weight based on 100 parts by weight of the phenol-modified lignin resin. It is. By setting the lower limit or more, the mechanical strength of the cured product of the phenol-modified lignin resin composition can be increased. When the content is not more than the above upper limit, the production stability can be improved.

  The phenol-modified lignin resin composition of the present embodiment may contain components other than the above-described components as long as the object of the present invention is not impaired. Examples of the other components include additives such as an elastomer, a curing accelerator, a resin component, a release agent, a pigment, a flame retardant, an adhesion improver, and a coupling agent. The phenol-modified lignin resin composition may contain a solvent.

The phenol-modified lignin resin composition of the present embodiment may contain an elastomer, if necessary.
Examples of the elastomer include, but are not particularly limited to, acrylonitrile butadiene rubber, isoprene, styrene butadiene rubber, and ethylene propylene rubber. Among them, acrylonitrile butadiene rubber is preferable. The use of an elastomer can provide particularly toughness.

  The phenol-modified lignin resin composition of the present embodiment may contain a curing accelerator, if necessary. A curing accelerator can be used in combination with the curing agent. Thereby, heat stability and curability can be improved.

  The curing accelerator is not particularly limited, and ordinary curing accelerators can be used. For example, magnesium oxide, calcium hydroxide, oxides or hydroxides of alkaline earth metals such as barium hydroxide, salicylic acid And aromatic carboxylic acids such as benzoic acid. The curing accelerator is used in an appropriate amount, for example, in a proportion of 0.5 to 20 parts by weight based on 100 parts by weight of the phenol-modified lignin resin.

  The phenol-modified lignin resin composition of the present embodiment can be used in combination with known resin materials for the purpose of improving properties and the like. Examples of such a resin component include a resin having a triazine ring such as a urea (urea) resin and a melamine resin, a bismaleimide resin, a polyurethane resin, a silicone resin, a resin having a benzoxazine ring, a cyanate ester resin, and a polyvinyl butyral resin. And polyvinyl acetate resin. If necessary, these plural kinds can be used in combination.

  Examples of the release agent include stearic acid, calcium stearate, zinc stearate, and polyethylene.

  Examples of the pigment include carbon black.

As an example of the method for producing the phenol-modified lignin resin composition, one or more raw material components are previously melt-kneaded with a kneader, a roll, or the like, and then uniformly mixed with other raw material components, or the total The raw material components are obtained by melt-kneading with a kneading device alone such as a roll, a co-kneader, a twin-screw extruder or a combination of a roll and another mixing device, followed by granulation or pulverization.
In addition, the shape of the phenol-modified lignin resin composition of the present embodiment is not particularly limited, and examples thereof include powder, granules, tablets, sheets, and the like.

  By molding the obtained phenol-modified lignin resin composition, a molded article (structure) having a cured product of the phenol-modified lignin resin composition is obtained. That is, the method for producing a structure including the cured product of the phenol-modified lignin resin composition of the present embodiment can include a step of molding the phenol-modified lignin resin composition.

  The method for molding the molded article is not particularly limited, but for example, transfer molding, compression molding, injection molding, or the like can be used.

  Examples of the molded product of the present embodiment include, for example, molded products used for automobiles, aircraft, railway vehicles, ships, general-purpose machines, household electric appliances and their peripheral parts, or their housings, structural / mechanical parts, and electric / electronic devices. Molded articles used for electronic components are exemplified.

  Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than the above can be adopted.

  Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the description of these examples.

<Preparation of resin material>
(Synthesis of resin material A)
In a three-necked flask equipped with a stirrer and a thermometer, 400 parts by mass of phenol and 4 parts by mass of oxalic acid are charged, heated to 100 ° C., and 240 parts by mass of 37% formalin are added dropwise over 30 minutes. And stirred at 100 ° C. for 1 hour. Next, the condensed water and unreacted phenol were distilled off under reduced pressure while raising the temperature. When the residual phenol became 2% or less, 160 parts by mass of lignin was charged into the flask and mixed. The product was taken out of the flask to obtain 518 parts by mass of a lignin-modified novolak-type phenol resin (resin material A) having a lignin modification ratio of 30%. The resin yield was 81%.

(Resin material B)
As the resin material B, a novolak type phenol resin (manufactured by Sumitomo Bakelite Co., Ltd., product name: PR-53195) was used.

(Synthesis of resin material C)
500 parts by mass of 150 parts by mass (30% by mass) of lignin and 350 parts by mass (70% by mass) of a phenol resin (manufactured by Sumitomo Bakelite Co., Ltd., product name: PR-53195) in a three-necked flask equipped with a stirrer and a thermometer. Of acetone and the solvent was mixed at room temperature. Next, acetone was completely distilled off under reduced pressure while increasing the temperature, and then the mixture was taken out of the flask in a molten state to obtain a mixture (resin material) C of lignin and a phenol resin.

(Synthesis of resin material D)
After 400 parts by mass of phenol and 4 parts by mass of oxalic acid are added to a three-necked flask equipped with a stirrer and a thermometer, 160 parts by mass of lignin are charged and heated to 100 ° C., and 240 parts by mass of 37% formalin are added for 30 minutes. After completion of the dropwise addition, the mixture was stirred at 100 ° C. for 1 hour. Next, the condensed water and unreacted phenol were distilled off under reduced pressure while increasing the temperature. When the residual phenol became 2% or less, the product was taken out of the flask, and a lignin-modified novolak type phenol resin (resin material D) 504 was used. Parts by weight were obtained. The resin yield was 79%.

(Synthesis of resin material E)
A three-necked flask equipped with a stirrer and a thermometer was charged with 150 parts by mass (30% by mass) of lignin and 350 parts by mass (70% by mass) of a phenol resin (manufactured by Sumitomo Bakelite Co., Ltd., product name: PR-53195), After stirring and mixing under heating and melting, the mixture was taken out of the flask in a molten state to obtain a mixture of lignin and a phenol resin (resin material E).

  The obtained resin materials A to D were evaluated based on the following evaluation items.

<Preparation of molded products>
To 100 parts by mass of the resin material (resin materials A to D obtained), 15 parts by mass of hexamethylenetetramine (curing agent) was added at room temperature, and pulverized and mixed to prepare a phenol-modified lignin resin composition.
To the obtained phenol-modified lignin resin composition, 160 parts by weight of glass fiber (filler, glass milled fiber, manufactured by Nitto Boseki Co., Ltd., standard fiber diameter 10 ± 1.5 μm, average fiber length 90 μm), additives ( 8 parts by weight of stearic acid (manufactured by NOF Corporation) and carbon black (manufactured by Mitsubishi Chemical Corporation, # 5) are blended, kneaded with a heating roll at about 90 ° C. for about 5 minutes, cooled, pulverized, and then phenol-modified lignin. A resin composition (molding material) was obtained.
The obtained molding material was transfer-molded under the conditions of 175 ° C., 20 MPa, and 3 minutes, and further heat-treated at 180 ° C. for 8 hours to obtain a molded product (a cured product of a phenol-modified lignin resin composition).

・ Mechanical characteristics (bending characteristics at room temperature)
The flexural modulus and flexural strength were measured at 25 ° C. in accordance with JIS K 6911 “General Test Method for Thermosetting Plastics”. Specifically, a three-point bending test was performed by applying a load at a speed of 2 mm / min with a precision universal testing machine (Autograph AG-Xplus manufactured by Shimadzu Corporation).
・ Mechanical properties (bending properties when heated)
At 150 ° C., the flexural modulus and flexural strength were measured in the same manner as described above.
・ Mechanical properties (impact strength)
The Charpy impact strength was measured according to JIS K 6911 “General thermosetting plastic test method”.
・ Electrical characteristics (insulation resistance)
The insulation resistance was measured in accordance with JIS K 6911 "General Test Method for Thermosetting Plastics".

Compared with Comparative Examples 1 to 4, the resin material of Example 1 showed improved results in the mechanical properties of the molded article and excellent electrical properties.
The method for producing the resin material of Comparative Example 2 requires a large amount of acetone, which increases the raw material cost. In addition, the produced novolak resin is dissolved at room temperature with a large amount of acetone, deacetone-treated, and taken out after melting. Therefore, it was found that the total yield was lower and the production time was longer than in Example 1.
In the method for producing the resin material of Comparative Example 3, it was found that more unreacted phenol remained than in Example 1, and the resin yield was reduced.
Since the method for producing the resin material of Comparative Example 4 involves a process of charging, re-melting, and melt-mixing the produced novolak resin, the total yield is lower and the production time is lower than in Example 1. It has been found that the total cost increases as the length increases.

Claims (15)

A reaction step of reacting a raw material containing phenols and aldehydes in a container to obtain a reaction solution;
A method for producing a resin material containing a phenol-modified lignin resin, comprising: after the reaction step, an addition step of adding lignin to the reaction solution in a heated state in the container. It is a manufacturing method of the resin material of Claim 1, Comprising:
A method for producing a resin material containing a phenol-modified lignin resin, wherein the molar ratio of the aldehyde to the phenol in the reaction step is 0.4 or more and 1.0 or less. It is a manufacturing method of the resin material of Claim 1 or 2, Comprising:
A method for producing a resin material containing a phenol-modified lignin resin, wherein the raw material contains lignin in the reaction step. A method for producing a resin material according to any one of claims 1 to 3,
A method for producing a resin material, wherein a heated state is maintained from the reaction step to the addition step. It is a manufacturing method of the resin material according to any one of claims 1 to 4,
A method for producing a resin material, comprising a dehydration step of performing dehydration on the reaction solution in the container before the addition step. It is a manufacturing method of the resin material according to any one of claims 1 to 5,
The method for producing a resin material, wherein the lignins are added to the reaction solution containing the unreacted phenols in the adding step. A method for producing a resin material according to any one of claims 1 to 6,
A method for producing a resin material, comprising: a removing step of removing the phenol remaining in the reaction solution in the container after the adding step. It is a manufacturing method of the resin material according to any one of claims 1 to 7,
A method for producing a resin material, wherein the reaction step is performed under acidic conditions. It is a manufacturing method of the resin material according to any one of claims 1 to 8,
A method for producing a resin material, wherein the lignin includes lignin or a lignin derivative. It is a manufacturing method of the resin material according to any one of claims 1 to 9,
A method for producing a resin material, wherein the aldehyde contains formaldehyde or acetaldehyde. It is a manufacturing method of the resin material according to any one of claims 1 to 10,
A method for producing a resin material, wherein the phenols include at least one selected from the group consisting of phenol, cresol, xylenol, alkylphenol, and bisphenol. It is a manufacturing method of the resin material according to any one of claims 1 to 11,
A method for producing a resin material, wherein the phenol-modified lignin resin has a lignin modification ratio of 10% or more and 50% or less. A resin material obtained by the method for producing a resin material according to any one of claims 1 to 12,
A curing agent,
A method for producing a phenol-modified lignin resin composition, comprising the step of mixing A method for producing a phenol-modified lignin resin composition according to claim 13,
A method for producing a phenol-modified lignin resin composition, comprising a step of further mixing a filler.   A method for producing a structure comprising a cured product of a phenol-modified lignin resin composition, comprising a step of molding the phenol-modified lignin resin composition obtained by the method for producing a phenol-modified lignin resin composition according to claim 13. .