WO2015147165A1

WO2015147165A1 - Phenol-modified lignin resin, method for producing same, resin composition, rubber composition, and cured product

Info

Publication number: WO2015147165A1
Application number: PCT/JP2015/059372
Authority: WO
Inventors: 村井威俊; 田子浩明
Original assignee: 住友ベークライト株式会社
Priority date: 2014-03-28
Filing date: 2015-03-26
Publication date: 2015-10-01
Also published as: JPWO2015147165A1; JP6541007B2; CN105873970B; CN105873970A

Abstract

Provided is a phenol-modified lignin resin having improved curing properties and excellent flexural strength, or a phenol-modified lignin resin having a rubber-reinforcing effect. One aspect of the present invention relates to a phenol-modified lignin resin obtained by reacting a lignin, a phenol compound and an aldehyde in the presence of an acid. In one or more embodiments, the number average molecular weight of the lignin is 100-5000 and the molar ratio (F/P) of the aldehyde (F) and the phenol compound (P) in the reaction is 0.4-1.5. In other embodiment(s), the phenol-modified lignin resin is used to reinforce a rubber.

Description

Phenol-modified lignin resin, method for producing the same, resin composition, rubber composition, and cured product

The present disclosure relates to a phenol-modified lignin resin and a method for producing the same, and a resin composition, a rubber composition, and a cured product.

In recent years, there has been a demand for the development of technology that uses biomass typified by plants or plant-derived processed products, and technology that converts them into chemical products, resin products, and the like. For example, many wood-based waste materials 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, utilization of plant-derived biomass, reuse of wood-based waste materials, and recycling are beginning to be studied. For example, Patent Document 1 discloses an example in which wood is treated with acid and phenol.

General components of general plants are cellulose derivatives, hemicellulose derivatives and lignin derivatives. Of these, lignin contained at a ratio of about 30% has a structure containing abundant aromatic rings, unlike cellulose derivatives and hemicellulose derivatives. Therefore, it is mainly a resin with excellent heat resistance and reactivity by taking out lignin. Examples of use as a raw material for resin compositions and tires are disclosed (for example, see Patent Documents 2 and 3).

One example of its use is lignin-modified phenolic resin (Patent Documents 4 and 5).
Patent Documents 4 and 5 disclose lignin-modified phenolic resins in which phenol or a phenol derivative, an aldehyde, and lignin are reacted in the presence of an acid so that a part of the phenol or phenol derivative is substituted with lignin. It is disclosed that it can be obtained.

However, although the lignin-modified phenolic resins of Patent Documents 4 and 5 have improved moldability and frictional properties, there is not much improvement in the mechanical strength of the molding material, and the phenol reaction rate is low. Therefore, productivity was difficult.

On the other hand, since the lignin derivative has a highly polar structure rich in phenolic hydroxyl groups and alcoholic hydroxyl groups, performance as a reinforcing material for rubber compositions is also expected.

However, in Patent Document 2, the lignin derivative is used as a filler instead of a carbon black instead of a phenol resin, and although the rubber elasticity of the rubber composition is increased, the mechanical strength is decreased.

Patent Document 5 discloses an example in which phenolic lignin obtained by directly adding lignin to phenol with concentrated sulfuric acid is used as a rubber reinforcing resin as a substitute for the phenol resin, but the rubber reinforcing effect such as rubber elasticity is sufficient. There wasn't.

JP 2004-352978 A Special table 2011-520208 gazette JP 2008-285626 A JP 2008-156601 A JP 2013-199561 A

As mentioned above, it is expected to develop a method that can increase the mechanical strength of molding materials by converting the lignin derivative to phenol-modified lignin with high production efficiency, and to obtain a high rubber reinforcing effect by using the lignin derivative. Also, the development of an effective method for changing the physical properties of rubber as required was expected.

In one or more embodiments, the present disclosure provides a phenol-modified lignin resin with improved curability and excellent resin strength after curing.

In one or a plurality of embodiments, the present disclosure provides a phenol-modified lignin resin for rubber reinforcement modified with phenols. In one or a plurality of embodiments, the present disclosure provides a phenol-modified lignin resin having a high rubber reinforcing effect. In one or a plurality of embodiments, the present disclosure provides a rubber composition that exhibits excellent elastic modulus, low hysteresis loss, tensile properties, or excellent balance of these properties.

In one or a plurality of embodiments, the present disclosure is a phenol-modified lignin resin obtained by reacting lignins, phenols, and aldehydes in the presence of an acid, the number average of the lignins Phenol-modified lignin having a molecular weight of 100 or more and 5000 or less, and a molar ratio (F / P) of aldehydes (F), phenols and (P) in the reaction of 0.4 or more and 1.5 or less It relates to resin.

In one or a plurality of embodiments, the present disclosure is a method for producing a phenol-modified lignin resin, which comprises reacting a lignin, a phenol, and an aldehyde in the presence of an acid. The number average molecular weight is 100 or more and 5000 or less, and the molar ratio (F / P) of aldehydes (F), phenols and (P) in the reaction is 0.4 or more and 1.5 or less. Regarding the method.

In one or a plurality of embodiments, the present disclosure is a phenol-modified lignin resin for rubber reinforcement, which is obtained by reacting a mixture containing lignins, phenols, and aldehydes. It relates to a modified lignin resin.

In one or a plurality of embodiments, the present disclosure relates to a rubber composition including the phenol-modified lignin resin according to the present disclosure and a diene rubber.
In one or a plurality of embodiments, the present disclosure relates to a cured product obtained by curing the rubber composition in the present disclosure.

The present disclosure relates to a resin composition containing the phenol-modified lignin resin according to the present disclosure in one or a plurality of embodiments.

According to the present disclosure, in one or a plurality of embodiments, it is possible to provide a phenol-modified lignin resin having improved curability and excellent resin strength after curing.

According to the present disclosure, in one or a plurality of embodiments, it is possible to develop a lignin modified with phenol or a phenol derivative, thereby providing a phenol-modified lignin resin having a high rubber reinforcing effect. Furthermore, according to the present disclosure, in one or a plurality of embodiments, it is possible to provide a rubber composition that is excellent in elastic modulus, low hysteresis loss, and tensile properties.

The present disclosure is excellent in curability by setting the molar ratio (F / P) of aldehydes (F) and phenols (P) to 0.4 or more and 1.5 or less in the synthesis of phenol-modified lignin resin. Based on the finding that a phenol-modified lignin resin is obtained. Further, the present disclosure is based on the finding that, in the synthesis of a phenol-modified lignin resin, a phenol-modified lignin resin having excellent resin strength can be obtained by setting F / P to be 0.4 or more and 1.5 or less.

In the synthesis of phenol-modified lignin resin, it is known that bending strength is improved by reacting lignin and phenol. The present inventors considered that when the amount of phenol reacted with lignin is increased, the crosslinking point of the obtained phenol-modified lignin resin is increased, and as a result, the resin strength is excellent. In addition, the present inventors use lignin having a number average molecular weight of 100 or more and 5000 or less, and by setting F / P to 0.4 or more and 1.5 or less, the curability of the resulting phenol-modified lignin resin. Has been found to improve the resin strength. The reason is not necessarily clear, but is estimated as follows. By setting F / P to be 0.4 or more and 1.5 or less, lignins and phenols have more covalent bonds and have a highly complex structure, which further enhances curability and resin strength. It is thought. However, the present disclosure is not limited to these mechanisms.

According to the phenol-modified lignin resin of the present disclosure, in one or a plurality of embodiments, even when the amounts of phenols and aldehydes that react with lignin are the same amount or less, F / P is out of the above range. Compared to (when less than 0.4 or exceeding 1.5), it is possible to achieve an effect of exhibiting higher curability and resin strength. Moreover, according to the phenol modified lignin resin of this indication, in one or some embodiment, there can exist an effect that it is excellent in sclerosis | hardenability and a moldability. In the present disclosure, the curability includes a curing time and a curing degree in one or a plurality of embodiments. In one or more embodiments, the resin strength in the present disclosure includes bending strength.

In the present disclosure, the “phenol-modified lignin resin” means a product obtained by reacting lignin and / or a lignin derivative (also referred to as “lignins” in the present disclosure), a phenol and an aldehyde in the presence of an acid. Say. In one or a plurality of embodiments, the phenol-modified lignin resin in the present disclosure may include a product obtained by further modifying a lignin by reacting an aldehyde and a phenol.

In one or a plurality of embodiments, the present disclosure is a phenol-modified lignin resin obtained by reacting a lignin, a phenol, and an aldehyde in the presence of an acid, and the number average molecular weight of the lignin is 100. A phenol-modified lignin resin (hereinafter referred to as “this disclosure”) having a molar ratio (F / P) of aldehydes (F) to phenols (P) in the reaction of 0.4 to 1.5. Also referred to as “phenol-modified lignin resin”. In one or a plurality of embodiments, the phenol-modified lignin resin of the present disclosure includes, in the presence of an acid, a lignin having a number average molecular weight of 100 or more and 5000 or less, a phenol and an aldehyde, and an aldehyde (F). It can manufacture by making it react with the molar ratio (F / P) with phenols (P) 0.4-1.5.

<Lignin and lignin derivatives (lignins)>
In the present disclosure, lignin refers to one selected from the group consisting of lignin, lignin derivatives, and combinations thereof.
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. In one or a plurality of embodiments, lignin in the present disclosure includes pulp lignin such as kraft lignin, lignin sulfonic acid, and organosolv lignin; explosive lignin; lignophenol; phenolized lignin and the like. The origin of lignin is not particularly limited, and in one or a plurality of embodiments, examples thereof include wood and herbs that contain lignin and a woody part is formed, and conifers such as cedar, pine and cypress, beech, birch, oak and zelkova. And broad-leaved trees such as rice, wheat, corn and bamboo.

In the present disclosure, the “lignin derivative” refers to a compound having a unit structure constituting lignin or a structure similar to the unit structure constituting lignin. In one or a plurality of embodiments, 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 and biological degradation. For these reasons, the lignin derivative is useful as a resin raw material.

As one or a plurality of embodiments, the lignin derivative includes guaiacylpropane (ferulic acid) represented by the formula (A) of the following formula (1), syringylpropane (sinapic acid) represented by the following formula (B), And 4-hydroxyphenylpropane (coumaric acid) represented by the following formula (C). The composition of the lignin derivative varies depending on the biomass as the raw material. A lignin derivative mainly containing a guaiacylpropane structure is extracted from conifers. From hardwoods, lignin derivatives mainly containing guaiacylpropane structure and syringylpropane structure are extracted. From the herbs, lignin derivatives mainly containing a guaiacylpropane structure, a syringylpropane structure and a 4-hydroxyphenylpropane structure are extracted.

The lignin derivative is preferably one obtained by decomposing biomass in one or a plurality of embodiments. Biomass, which is obtained by capturing and fixing carbon dioxide in the atmosphere during the photosynthesis process, contributes to the suppression of the increase in atmospheric carbon dioxide. This can contribute to the suppression of conversion. Examples of biomass include lignocellulosic biomass in one or more embodiments. Examples of lignocellulosic biomass include, in one or more embodiments, plant leaves, bark, branches and wood containing lignin, and processed products thereof. Examples of plants containing lignin include the aforementioned broad-leaved trees, conifers, and gramineous plants. In one or more embodiments, the decomposition method includes 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, and a cresol sulfate method. And pulp production methods. 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 preferred. From the viewpoint of cost, it is preferable to use a by-product using biomass. In one or more embodiments, the lignin derivative can be prepared by decomposing biomass in the presence of a solvent at 150 to 400 ° C., 1 to 40 MPa, and 8 hours or less. In one or more embodiments, the lignin derivative can be prepared by a method disclosed in JP2009-084320A, JP2012-201828A, or the like.

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

In one or a plurality of embodiments, the lignin derivative preferably has a large number of reaction sites on which the curing agent acts by an electrophilic substitution reaction on the aromatic ring, and has better reactivity when there are fewer steric hindrances near the reaction site. Therefore, it is preferable that at least one of the ortho-position and para-position of the aromatic ring containing a phenolic hydroxyl group is unsubstituted. As the lignin derivative, those disclosed in JP2009-084320A, JP2012-201828A, etc. can be used in one or a plurality of embodiments.

In addition to the above basic structure, the lignin derivative may be a lignin derivative having a functional group (lignin secondary derivative).

The functional group possessed by the lignin secondary derivative is not particularly limited, but for example, those in which two or more of the same functional groups can react with each other, or those capable of reacting with other functional groups are suitable. 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 (methylolated) is preferably used. Such a lignin secondary derivative is self-cross-linked by a self-condensation reaction between methylol groups and is more cross-linked to an alkoxymethyl group or a hydroxyl group in the following cross-linking agent. As a result, a cured product having a particularly homogeneous and rigid skeleton and excellent in solvent resistance can be obtained.

In one or more embodiments, the lignin and the lignin derivative have a number average molecular weight of 100 or more and 5000 or less. By reacting a lignin having a number average molecular weight within the above range with the F / P ratio of the present disclosure, a phenol-modified lignin resin that can be molded and has excellent resin strength can be obtained. In one or a plurality of embodiments, the number average molecular weight is 100 or more and 5000 or less, and is 4000 or less, 3000 or less, 2000 or less, 1500 or less, 1200 or less, or 1000 or less. In one or more embodiments, the number average molecular weight is 200 or more, 250 or more, 300 or more, or 350 or more. The number average molecular weight is a polystyrene-equivalent number average molecular weight measured by gel permeation chromatography, and can be determined by the method of Examples.

The number average molecular weight of the lignin and the lignin derivative is such that, in one or a plurality of embodiments, the workability of a normal denaturation step is improved. Are preferable, and those of 300 or more and 3000 or less are more preferable. A phenol-modified lignin resin modified with such a number-average molecular weight lignin derivative is excellent in workability reactivity at the time of mixing in the modification step, and a phenol-modified lignin resin easy to mix at the time of rubber mixing is obtained. It is done.

The weight average molecular weights of lignin and lignin derivatives are 100 or more and 5000 or less in one or more embodiments from the viewpoint that a phenol-modified lignin resin having excellent moldability and resin strength is obtained. In terms of one or more embodiments, the weight average molecular weight is 4000 or less, 3500 or less, 3000 or less, 2500 or less, 2100 or less, or 1500 or less from the viewpoint of more uniformly mixing lignins and phenol during production. The weight average molecular weight is 200 or more or 400 or more in one or more embodiments. The weight average molecular weight is a number average molecular weight in terms of polystyrene measured by gel permeation chromatography, and can be determined by the method of the example.

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

The lignin derivative in the present disclosure is dissolved in a solvent to prepare a measurement sample. 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, connect the GPC system “HLC-8320GPC (manufactured by Tosoh)” with “TSKgelGMMHXL (manufactured by Tosoh)” and “G2000HXL (manufactured by Tosoh)”, which are organic general-purpose columns packed with styrene polymer filler. To do.

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.

Furthermore, the lignin derivative in the present disclosure may have a carboxyl group. When it has the said carboxyl group, it may bridge | crosslink with the crosslinking agent described below, and since a crosslinking density can be improved by a crosslinking point increasing, it is excellent in solvent resistance. Moreover, since it may act as a catalyst of a crosslinking agent and the crosslinking reaction of a lignin derivative and a crosslinking agent can be accelerated | stimulated, it is excellent in solvent resistance and a cure rate.

When the above 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.

Although the softening point of the lignin derivative of the present disclosure is not particularly limited, it is preferably 200 ° C. or lower because the workability of a normal denaturation process is improved. It is preferable that the temperature is 85 ° C. or higher and 150 ° C. or lower, more preferably 90 ° C. or higher and 140 ° C. or lower. If the softening point is less than the above range, there is too much heat melting and fluidity, and many burrs are generated at the time of molding, and the handling property is poor when making the resin composition and rubber composition. There is a big thing. On the other hand, if the softening point exceeds the above range, the heat melting property and fluidity may be poor and molding may not be possible. The softening point is changed by controlling the amount of the volatile component within a certain range, controlling the average molecular weight of the lignin derivative according to the decomposition temperature of the biomass, and replacing a part of the lignin derivative with the other resin component. Can do. Note that the lignin derivative of the present disclosure can be similarly made into a resin composition and a rubber composition within the above-described range even when a part of the solvent-insoluble component is included.

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.

When using a lignin derivative obtained by decomposing biomass, a large amount of low molecular weight components may be mixed, which may cause a decrease in volatile content, odor, and softening point during heating. These components can be used as they are, or can be removed by heating, drying or the like of the lignin derivative to control the softening point and odor.

<Phenols>
In one or some embodiment, phenol, phenol derivatives, and these combination are mentioned as phenols. As a phenol derivative, in one or some embodiment, what is necessary is just to have a phenol skeleton, and you may have arbitrary substituents on a benzene ring. Examples of the substituent include, in one or more embodiments, a hydroxy group; a lower alkyl group such as a methyl group or an ethyl group; a halogen atom such as fluorine, chlorine, bromine, or iodine; an amino group; a nitro group; It is done. 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, 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, and the alkyl chain may have a branched chain or an unsaturated bond as long as the carbon number is within the above range. The alkyl chain can be substituted at any of ortho, meta and para-substituted alkylphenols. For example, ethylphenol, propylphenol, isopropylphenol, butylphenol, secondary butylphenol, tertiary butylphenol, amylphenol, tertiary aminophenol, hexylphenol, heptylphenol, octylphenol, tertiary octylphenol, nonylphenol, tertiary nonylphenol, decylphenol, Undecylphenol, dodecylphenol, tridecylphenol, tetradecylphenol, pentadecylphenol, cardanol, curdole, urushiol, hexadecylphenol, methyl curdal, heptadecylphenol, raccol, thiol, octadecylphenol. As vegetable oil, cashew nut shell liquid (cashew oil), urushi extract, and the like can be used.

<Aldehydes>
Examples of aldehydes include, in one or more embodiments, formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, polyoxymethylene, chloral, hexamethylenetetramine, furfural, glyoxal, n-butyraldehyde, caproaldehyde, allylaldehyde. Benzaldehyde, crotonaldehyde, acrolein, tetraoxymethylene, phenylacetaldehyde, o-tolualdehyde, salicylaldehyde, paraxylene dimethyl ether and the like. Preferable examples include formaldehyde, paraformaldehyde, trioxane, polyoxymethylene, acetaldehyde, paraxylene dimethyl ether, and combinations thereof. These may be used alone or in combination of two or more.

<Acid>
The acid may be any acid as long as it can be used as a reaction catalyst in one or a plurality of embodiments, and organic acids, inorganic acids, and combinations thereof can be used. Examples of the organic acid include, in one or more embodiments, acetic acid, formic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, benzoic acid, salicylic acid, sulfonic acid, phenolsulfonic acid, paratoluenesulfonic acid, and the like. Can be mentioned. Examples of the inorganic acid include hydrochloric acid, sulfuric acid, sulfuric acid ester, phosphoric acid, and phosphoric acid ester in one or more embodiments.

The molar ratio (F / P) of aldehydes (F) and phenols (P) in the reaction is 0.4 or more and 1.5 or less. In view of curability of the phenol-modified lignin resin and / or improvement in resin strength, 0.40 or more, 0.45 or more, or 0.50 or more is preferable. From the viewpoint of suppressing an excessive increase in the softening temperature of the phenol-modified lignin resin, it is preferably 1.50 or less, 1.30 or less, or 1.20 or less.

In one or a plurality of embodiments, the weight average molecular weight of the phenol-modified lignin resin of the present disclosure is 1000 or more and 1500 or more, and is 10,000 or less. 6000 or less. In one or more embodiments, the number average molecular weight of the phenol-modified lignin resin is 300 or more, 400 or more, 500 or more, or 550 or more, and is 4000 or less, 2000 or less, 1500 or less, 1200 or less, 1100 or less, or 1000. It is as follows. A weight average molecular weight and a number average molecular weight can be calculated | required by the method of an Example.

In one or a plurality of embodiments, the softening point of the phenol-modified lignin resin is 65 ° C or higher, 75 ° C or higher, or 85 ° C or higher, and is 170 ° C or lower, 160 ° C or lower, or 150 ° C or lower.

The molar ratio (F / (P + L)) of aldehydes (F) and phenol or phenol derivative (P) and lignin derivative (L) in the reaction is not particularly limited, but since the rubber reinforcing effect is improved, the lower limit Is preferably 0.01 or more, 0.05 or more, or 0.1 or more. Depending on the lignin derivative used, it may gel and become infusible and insoluble, so the upper limit is preferably 5.0 or less, 3.0 or less, or 1.5 or less. Since lignin is a mixture having a plurality of phenol skeletons, the molar ratio can be calculated using the following formula in the molar ratio calculation in the present disclosure.
Number of moles of lignin per unit g = reciprocal of hydroxyl equivalent

In addition, the hydroxyl equivalent of the lignin derivative in the present disclosure can be measured by the following method, for example. In a stoppered Erlenmeyer flask, 1.0 g of the lignin derivative (A) sample and 4.0 g of acetic anhydride / pyridine (1/3 volume ratio) mixed solution were added and dissolved, and this solution was kept at 60 ° C. for 3 hours. Then, 1 ml of pure water is added. The solution thus obtained is titrated with a 0.1 mol / L NaOH aqueous solution with pH = 10 as the end point, and the hydroxyl equivalent can be determined by the following formula.
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 sodium hydroxide standard aqueous solution
N: Normality of sodium hydroxide standard aqueous solution

[Method for producing phenol-modified lignin resin]
In one or a plurality of embodiments, the present disclosure provides a method for producing a phenol-modified lignin resin (hereinafter referred to as “lighenic lignin resin”), which comprises reacting a lignin (lignin and / or lignin derivative), a phenol and an aldehyde in the presence of an acid. Also referred to as “production method of the present disclosure”. In the production method of the present disclosure, the number average molecular weight of the lignin is 100 or more and 5000 or less, and the molar ratio (F / P) of the aldehyde (F) and the phenol (P) in the reaction is 0.4 or more and 1 .5 or less. According to the production method of the present disclosure, the phenol-modified lignin resin of the present disclosure can be produced. In the production method of the present disclosure, lignins, phenols, aldehydes and acids are as described above.

In one or more embodiments, the production method of the present disclosure includes mixing lignins, phenols, aldehydes, and acids. In one or a plurality of embodiments, the production method of the present disclosure includes mixing phenols and lignins, and mixing the phenols and lignins with an acid in the mixture of phenols and lignins. And adding aldehydes to the mixture of phenols, lignins and acids.

The molar ratio (F / P) of aldehydes (F) to phenols (P) in the reaction is 0.4 to 1.5. F / P is preferably 0.40 or more, 0.45 or more, or 0.50 or more from the viewpoint of improving curability and / or resin strength. F / P is preferably 1.50 or less, 1.30 or less, or 1.20 or less from the viewpoint of suppressing an excessive increase in the softening temperature.

In one or a plurality of embodiments, the addition amount of phenols is 10 parts by weight or more, 20 parts by weight or more, or 30 parts by weight or more, and 500 parts by weight or less, 300 parts by weight with respect to 100 parts by weight of lignin. Or 200 parts by weight or less.

In one or more embodiments, the amount of acid added is 0.1 parts by weight or more, 0.3 parts by weight or more, or 0.5 parts by weight or more, and 10 parts by weight or less, based on 100 parts by weight of lignin. 8 parts by weight or less or 5 parts by weight or less.

The mixing of phenols and lignins may be performed at room temperature or while heating. From the viewpoint of more uniformly mixing the phenols and lignins, it is preferable to perform part or all of the mixing at a temperature close to or higher than the softening point of the lignins. As such temperature, in one or some embodiment, they are 80 to 180 degreeC, 100 to 160 degreeC, 110 to 150 degreeC, or 120 to 150 degreeC. As mixing time, in one or some embodiment, 5 minutes or more and 2 hours or less are mentioned.

In one or a plurality of embodiments, the reaction temperature of lignins, phenols and aldehydes in the presence of an acid is 70 to 130 ° C, or 80 to 120 ° C. In one or more embodiments, the reaction time is 10 minutes or longer and 6 hours or shorter, or 30 minutes or longer and 3 hours or shorter.

Furthermore, as an example of the production of the phenol-modified lignin resin, in one or a plurality of embodiments, the reaction product obtained may be dehydrated by performing atmospheric distillation and / or vacuum distillation. Thereby, a phenol-modified lignin resin with high purity is obtained.
The yield can be calculated by the following formula from the amounts of lignin, phenol, and formaldehyde added (in order, Lg, Ph, and FA).
Formula: (weight of reaction vessel after dehydration−weight of empty reaction vessel) / (Lg + Ph + FA)

In producing the phenol-modified lignin resin, a reaction solvent can be used. The reaction solvent is not particularly limited, and water, an organic solvent, and the like can be used. Usually, water or methanol is used. Moreover, you may carry out without using a reaction solvent, using paraformaldehyde as aldehydes. Examples of the organic solvent include alcohols such as methanol, ethanol, propanol, butanol, and amyl alcohol; ketones such as acetone and methyl ethyl ketone; glycols such as ethylene glycol, diethylene glycol, triethylene glycol, and glycerin; ethylene glycol monomethyl ether, ethylene Examples thereof include glycol ethers such as glycol monoethyl ether, diethylene glycol monomethyl ether and triethylene glycol monomethyl ether, ethers such as 1,4-dioxane, and aromatics such as toluene and xylene. These can be used alone or in combination of two or more.

The molecular weight of the phenol-modified lignin resin is not particularly limited, but the number average molecular weight is preferably 400 or more and 5000 or less, and more preferably 450 or more and 3000 or less. When the number average molecular weight is within the above range, the handleability of the resin is good. That is, when the number average molecular weight is within the above range, it can be avoided that it becomes a highly viscous substance, or it can be prevented from becoming a substance that solidifies during summer storage, or it can be dissolved in solvents. And compatibility with the composition can be maintained.

The number average molecular weight can be analyzed using the same method as for the lignin derivative. Depending on the modification conditions, some of the components may become solvent-insoluble components. In that case, most of the dissolved components may be analyzed, but when there are many insoluble components, it is desirable to change to a suitable solvent.

The lignin content (lignin ratio) of the phenol-modified lignin resin in the present disclosure is not particularly limited, but the lignin derivative is 15% by weight or more and 95% by weight or less based on the entire phenol-modified lignin resin. Preferably, it is 25 wt% or more and 85 wt% or less. When the lignin ratio is higher than the lower limit, it is preferable in that the effect of improving the tensile properties of rubber due to the lignin structure is exhibited. On the other hand, when it is lower than the above upper limit, it is preferable in that the effect of improving the elastic modulus of rubber is exhibited.

In one or a plurality of embodiments, the phenol-modified lignin resin in the present disclosure may retain phenols, aldehydes, or acids used in the reaction, but the risk of inhalation of the residue is reduced. Therefore, the volatility of phenol or phenol derivative is preferably less than 5%. In addition, it is also possible to make phenol or a phenol derivative less than 1%, and in that case, it is achieved by making a higher vacuum or a high temperature not exceeding 250 ° C. Any method may be used as a method for measuring the residual ratio of phenols. As an example, a calibration curve can be prepared by gas chromatography using a standard substance, and the phenol-modified lignin resin after preparation can be measured.

The form of the phenol-modified lignin resin in the present disclosure is not particularly limited, but may be fine powder, granular, pellet, or varnish. From the viewpoint of handling properties when kneading into rubber, it is preferable to use granular and pellet forms.

According to the production method of the present disclosure, in one or a plurality of embodiments, it is possible to produce an effect that a phenol-modified lignin resin can be produced with a high yield. According to the production method of the present disclosure, in one or a plurality of embodiments, the phenol-modified lignin resin can be produced with a high yield exceeding 60%, 65%, 70%, or 75%. Moreover, according to the manufacturing method of this indication, in one or some embodiment, there can exist an effect that the reactivity of phenols and lignin can be improved. According to the production method of the present disclosure, in one or a plurality of embodiments, the FP reaction rate is 0.43 or more, 0.45 or more, or 0.5 or more. The FP reaction rate can be determined by the method described in the examples.

In one or a plurality of embodiments, the phenol-modified lignin resin obtained by the production method of the present disclosure has an effect that the curability is improved and the resin strength after curing is excellent.

According to the phenol-modified lignin resin of the present disclosure, in one or a plurality of embodiments, as an example of the resin strength, a resin molded body having a bending strength of 70 MPa or more, or 90 MPa or more can be obtained. The bending strength is measured based on JIS K6911.

In one or a plurality of embodiments, the phenol-modified lignin resin of the present disclosure includes a crosslinking agent, a curing aid, a wood powder, fibers, a colorant, a release agent, a plasticizer, and / or a stabilizer as necessary. Etc., kneaded at a predetermined temperature, and then injection molded with an injection molding machine to produce a resin molded body. A lignin-modified phenolic resin may be used alone as a resin and cured, but in terms of further improving curability and shortening the molding cycle, in one or a plurality of embodiments, a novolac phenolic resin or an epoxy resin is used. , And isocyanates, and combinations thereof may be mixed.

Examples of the crosslinking agent include hexamethylenetetramine. Examples of the curing aid include slaked lime. Wood flour is obtained by crushing, crushing, and finely crushing wood and the like, and the average particle size is preferably 80 mesh. Examples of the fibers include cellulose obtained from wood and the like. Examples of the plasticizer include aliphatic dibasic acid esters, hydroxy polyvalent carboxylic acid esters, fatty acid esters, polyester compounds, and phosphoric acid esters. Examples of the stabilizer include metal soaps, phosphorus compounds, sulfur compounds, phenolic compounds, L-ascorbic acids, and epoxy compounds.

[Resin composition]
In another aspect, the present disclosure relates to a resin composition including the phenol-modified lignin resin according to the present disclosure. The resin composition of the present disclosure includes the phenol-modified lignin resin, besides this, a phenolic resin, a novolak-type phenolic resin, an epoxy resin, an isocyanate, and a combination thereof, as well as a filler and a crosslinking agent described later An agent or the like may be included. The method for producing a resin composition of the present disclosure may include a step of kneading a phenol-modified lignin resin and a phenolic resin. In addition, you may knead | mix, after mixing arbitrary components as needed. Moreover, the order of kneading | mixing is not specifically limited also when a filler, a crosslinking agent, anti-aging agent, and another additive are included. Examples of the kneader include a Banbury mixer, a kneader, a roll, and a biaxial kneader.

When using a phenol-modified lignin resin and a phenol-based resin, they may be kneaded as described above, but mixed by heating and melting, or containing a phenol-modified lignin resin and a phenol-based resin using a solvent or the like. You may obtain by removing after making it melt | dissolve uniformly. Alternatively, the phenol-modified lignin resin may be charged into a reactor after reaction with the phenol-based resin and melt-mixed. Alternatively, the phenol-modified lignin resin may be reacted to obtain a phenol after the reaction. A resin may be added and melt mixed. Other additives can be mixed in advance in the same manner.

As described above, when kneading or melt mixing, an organic solvent may be used as necessary. The organic solvent is not particularly limited. For example, methanol, ethanol, propanol, butanol, methyl cellosolve, acetone, methyl ethyl ketone, methyl isobutyl ketone, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl- Examples include 2-pyrrolidone, quinoline, cyclopentanone, tetrahydrofuran, cyclohexane, benzene, toluene, xylene, cresol, dichloromethane, chloroform, and the like, and one or a mixture of two or more of these is used. Further, the solid content concentration in the resin composition is not particularly limited, but is, for example, about 60 to 98% by mass, preferably about 70 to 95% by mass.

[Rubber composition]
The phenol-modified lignin resin described in the present disclosure can be used as a rubber composition. In this case, the rubber composition is characterized in that the phenol-modified lignin resin and diene rubber are included as raw rubber. Furthermore, the composition may contain a phenolic resin.

<Method for producing rubber composition>
As a manufacturing method of a rubber composition, the process of kneading | mixing raw material rubber and a phenol modified lignin resin is included. If necessary, the raw rubber and optional components may be premixed and then kneaded. Also, for example, the order of kneading is not particularly limited when a phenolic resin, a filler, a crosslinking agent, a vulcanizing agent, a vulcanization accelerator, an anti-aging agent, and other additives are included. . Examples of the kneader include a Banbury mixer, a kneader, and rolls.

Further, when kneading, an organic solvent may be used as necessary. The organic solvent is not particularly limited. For example, methanol, ethanol, propanol, butanol, methyl cellosolve, acetone, methyl ethyl ketone, methyl isobutyl ketone, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl- 2-pyrrolidone, quinoline, cyclopentanone, tetrahydrofuran, benzene, toluene, xylene, cresol, light oil, kerosene, kerosene, naphtha, benzine, gasoline, industrial gasoline, hexane, cyclohexane, dichloromethane, chloroform, etc. Among them, one kind or a mixture of two or more kinds is used. Further, the solid content concentration in the rubber composition is not particularly limited, but is, for example, about 60 to 98% by mass, preferably about 70 to 95% by mass.

<Raw rubber>
Examples of diene rubber that can be used in the present disclosure include natural rubber (NR), modified natural rubber, styrene butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), butyl rubber (IIR), and ethylene propylene diene rubber. (EPDM), acrylonitrile butadiene rubber (NBR), chloroprene rubber (CR) and the like can be exemplified, and these may be used alone or in admixture of two or more. In particular, natural rubber (NR), modified natural rubber, styrene butadiene rubber (SBR), and butadiene rubber (BR) are excellent in properties such as trauma resistance, wear resistance, fatigue resistance, and flex crack growth resistance. Of these, one or more rubbers are preferable, and one or more rubbers among natural rubber, styrene butadiene rubber (SBR), and butadiene rubber (BR) are more preferable.

The rubber composition of the present disclosure includes natural rubber and / or modified natural rubber, styrene butadiene rubber (SBR), and butadiene rubber (BR) so that the content in the rubber component is in the range of 50 to 100% by mass. It is preferable that 1 or more types are included. When the content is 50% by mass or more, the effect of improving E ′ (storage modulus) and the effect of reducing tan δ around 60 ° C. are particularly prominent.

The content of the diene rubber is not particularly limited, but is preferably 100 parts by weight or more and 10,000 parts by weight or less, and 200 parts by weight or more and 5000 parts by weight with respect to 100 parts by weight of the phenol-modified lignin resin. More preferably, it is 300 parts by weight or more and 2000 parts by weight or less. When the content of the diene rubber is too small, the hardness becomes too high and the elongation at the time of cutting may be reduced. When the content is too large, the reinforcing effect may be lowered.

The diene rubber in the present disclosure is a functional group-containing natural product containing at least one functional group selected from an alkoxyl group, an alkoxysilyl group, an epoxy group, a glycidyl group, a carbonyl group, an ester group, a hydroxy group, an amino group, and a silanol group. A rubber (modified natural rubber) and / or a functional group-containing diene rubber can be included. When natural rubber and / or diene rubber contains these functional groups, it reacts with or interacts with the surface of fillers such as silica and carbon black to improve the dispersibility of these fillers and improve rolling resistance. The effect is obtained.

When functional group-containing natural rubber (modified natural rubber) and / or functional group-containing diene rubber is included, alkoxyl group, alkoxysilyl group, epoxy group, glycidyl group, carbonyl group, ester group, hydroxy group, amino group, At least one functional group selected from silanol groups is preferably contained in the functional group-containing natural rubber or the functional group-containing diene rubber in the range of 0.001 to 80 mol%. If the content of the functional group is 0.001 mol% or more, the effect of reacting or interacting with the surface of the silica or carbon black can be obtained satisfactorily, and if it is 80 mol% or less, the unvulcanized rubber composition An increase in viscosity at the time of production is suppressed, and workability is improved. The content of such a functional group is more preferably in the range of 0.01 to 50 mol%, and further preferably in the range of 0.02 to 25 mol%.

As a method of incorporating natural rubber and / or diene rubber with at least one functional group selected from alkoxyl group, alkoxysilyl group, epoxy group, glycidyl group, carbonyl group, ester group, hydroxy group, amino group, silanol group For example, a method of introducing a functional group into a polymerization terminal of a styrene-butadiene copolymer polymerized with an organolithium initiator in a hydrocarbon solvent, a natural rubber or a diene rubber by the chlorohydrin method, direct oxidation And a method of epoxidation by a method such as a hydrogen peroxide method, an alkyl hydroperoxide method, and a peracid method.

(filler)
Next, the filler will be described.
In the present disclosure, a filler may be further used.
As a filler, what is normally used in a resin composition or a rubber composition is employable. As the filler, it is preferable to use one containing at least one selected from the group consisting of carbon black, silica, alumina, and cellulose fiber, and an inorganic filler is particularly preferable. In particular, it is preferable to include at least one selected from silica and carbon black. When carbon black is used, a good reinforcing effect can be obtained, and when silica is used, a tan δ reduction effect can be obtained well. However, when the resin composition of the present disclosure and silica are used in combination, E ′ (storage The effect of improving the elastic modulus) and the effect of reducing tan δ around 60 ° C. are particularly good.

The content of the filler is preferably in the range of 10 to 150 parts by mass with respect to 100 parts by mass of the rubber component. When the content of the filler is 10 parts by mass or more, the effect of improving E ′ (storage elastic modulus) of the rubber composition for tires is good, and when the content is 150 parts by mass or less, E ′ (Storage modulus) is less likely to increase excessively, the processability during preparation of the rubber composition is good, and the wear resistance and elongation at break due to the deterioration of the dispersibility of the filler in the rubber composition Etc., and an unnecessary increase in tan δ around 60 ° C. and the resulting deterioration in fuel consumption are less likely to occur.

When silica is blended as a filler, the silica is in the range of 10 to 150 parts by mass and the silane coupling agent is 1 to 20% by mass with respect to the silica content with respect to 100 parts by mass of the rubber component. It is preferable to mix each so that it may become in the range. In the tire rubber composition, when the silica content is 10 parts by mass or more with respect to 100 parts by mass of the rubber component, the effect of improving the E ′ (storage elastic modulus) of the tire rubber composition is good, and 150 parts by mass. When it is below, there is little possibility that E '(storage elastic modulus) will rise too much, and the workability at the time of preparation of the rubber composition for tires is good. Further, it is possible to reduce the possibility of incurring wear resistance and elongation at break due to deterioration of the dispersibility of silica in the rubber composition, and unnecessary increase of tan δ around 60 ° C. and resulting deterioration of fuel consumption. . The content of silica is further preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and further preferably 100 parts by mass or less, and further preferably 80 parts by mass or less.

As the silica, those conventionally used for reinforcing rubber can be used. For example, the silica can be appropriately selected from dry silica, wet silica, colloidal silica, and the like. In particular, it is preferable to use those having a nitrogen adsorption specific surface area (N2SA) in the range of 20 to 600 m ² / g, further in the range of 40 to 500 m ² / g, and further in the range of 50 to 450 m ² / g. When N2SA of silica is 20 m ² / g or more, it is preferable in terms of a large reinforcing effect on the tire rubber composition, and when it is 600 m ² / g or less, the dispersibility of the silica in the tire rubber composition is good. It is preferable in that it can prevent an increase in heat generation during use of a pneumatic tire using the rubber composition.

The rubber composition of the present disclosure can contain a filler other than the above depending on the application. When a filler is added, examples of the filler include talc, calcined clay, unfired clay, mica, silicates such as glass, oxides such as titanium oxide and alumina, magnesium silicate, and carbonic acid. Carbonates like calcium, magnesium carbonate, hydrotalcite, oxides like zinc oxide, magnesium oxide, hydroxides like aluminum hydroxide, magnesium hydroxide, barium hydroxide, calcium hydroxide, barium sulfate, Sulfate or sulfite such as calcium sulfate, calcium sulfite, zinc borate, barium metaborate, aluminum borate, borate such as calcium borate, sodium borate, aluminum nitride, boron nitride, silicon nitride Of inorganic fillers such as fine nitride powder, glass fiber, carbon fiber, etc. , Wood flour, pulp pulverized powder, cellulose fibers, cloth pulverized powder, cured thermosetting resin powder, aramid fibers, organic fillers, and the like, such as talc.

A cross-linking agent that cross-links the phenol-modified lignin resin or the phenol-based resin can be added to the resin composition and the rubber composition of the present disclosure as necessary. When a crosslinking agent is added, the crosslinking agent is not particularly limited as long as it can crosslink with a phenol-modified lignin resin or a phenolic resin, and may further crosslink with a rubber component. What contains the compound represented by following formula (2) is preferable.

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

The resin composition and rubber composition containing such a compound are excellent in mechanical properties after curing, and contribute to improving the durability and appearance of the cured product. This is because the compound represented by the above formula (2) contained in the cross-linking agent can form a polyfunctional cross-linking point, so that the phenol-modified lignin resin is uniformly and rigidly cross-linked. This is because a skeleton is formed. The rigid skeleton will improve the mechanical properties and durability (boiling resistance, etc.) of the cured product, or improve the rubber reinforcing effect.

As described above, —CH ₂ OR is a nitrogen atom of a melamine residue, a nitrogen atom of a primary amino group of a urea residue, a nitrogen atom of a secondary amino group of a glycolyl residue, or a secondary amino group of an imidazolidinone residue. It is directly bonded to any one of the nitrogen atom of the group and the aromatic ring carbon atom of the aromatic ring residue, but two or more “—CH ₂ OR” are bonded to the same nitrogen atom or carbon atom. In such a case, it is preferable that “R” contained in at least one of “—CH ₂ OR” is an alkyl group. Thereby, a phenol modified lignin resin can be bridge | crosslinked reliably.

In the present specification, the melamine residue refers to a group having a melamine skeleton represented by the following formula (3).

In this specification, the urea residue refers to a group having a urea skeleton represented by the following formula (4).

In this specification, the glycolyl residue refers to a group having a glycolyl skeleton represented by the following formula (5).

In the present specification, the imidazolidinone residue means a group having an imidazolidinone skeleton represented by the following formula (6).

In the present specification, the aromatic ring residue means a group having an aromatic ring (benzene ring).

As the compound represented by the above formula (2), a compound represented by any one of the following formulas (7) to (10) is particularly preferably used. These react with a crosslinking reaction point on the aromatic ring contained in the phenol skeleton in the phenol-modified lignin resin to surely crosslink the phenol-modified lignin resin and cause self-crosslinking by a self-condensation reaction between functional groups. As a result, a cured product having a particularly homogeneous and rigid skeleton and excellent in mechanical properties, durability and appearance can be obtained, and a rubber cured product excellent in elastic modulus or low hysteresis loss can be obtained.

[In Formula (7), X is CH ₂ OR or a hydrogen atom, and R is independently an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. N represents an integer of 1 to 3. ]

[In formula (8), R is independently an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. ]

[In Formula (9), R is independently an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. ]

[In the formula (10), R is independently an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. ]

As the compound represented by the above formula (7), a compound represented by the following formula (11) or (12) is particularly preferably used. These react with the cross-linking reaction points on the aromatic ring contained in the phenol skeleton in the phenol-modified lignin resin to specifically cross-link the phenol-modified lignin resin and cause self-crosslinking by self-condensation reaction between functional groups. . As a result, a cured product having a homogeneous and rigid skeleton, excellent mechanical properties, durability and appearance, and a rubber cured product excellent in elastic modulus or low hysteresis loss can be obtained.

[In the formula (11), n represents an integer of 1 to 3. ]

[In the formula (12), n represents an integer of 1 to 3. ]

Further, the crosslinking agent may contain at least one compound of hemisamethylenetetramine, quinuclidine and pyridine instead of or together with the compound represented by the formula (2). . A cured product containing such a cross-linking agent has excellent mechanical strength, high durability and appearance, and a cured rubber product having excellent elastic modulus or low hysteresis loss is obtained. This is because hexamethylenetetramine, quinuclidine, and pididine cross-link the phenol-modified lignin resin at high density and uniformly to form a homogeneous and rigid skeleton.

Further, as the cross-linking agent, cross-linking agent components other than the above compounds may be used. Examples of the cross-linking agent component other than the above compound include, for example, orthocresol novolac epoxy resin, bisphenol A type epoxy resin, epoxidized glycerin, epoxidized linseed oil, epoxy resin such as epoxidized soybean oil, hexamethylene diisocyanate, toluene diisocyanate. As an isocyanate compound, a compound capable of crosslinking by electrophilic substitution reaction on the aromatic ring of a phenol-modified lignin resin, aldehydes such as formaldehyde, acetaldehyde, paraformaldehyde, furfural, aldehyde sources such as polyoxymethylene, hexa In addition to methylenetetramine, mention may be made of known phenolic resins such as resol type phenolic resins, known crosslinking agents, compounds capable of crosslinking by electrophilic substitution reaction on aromatic rings of lignin derivatives, etc. It can be. Further, the amount of the compound is preferably 5 to 150 parts by mass, more preferably 7.5 to 50 parts by mass with respect to 100 parts by mass of the phenol-modified lignin resin.

<Other ingredients>
The rubber composition of the present disclosure includes, in addition to a rubber component, a phenol-modified lignin resin, and a filler, sulfur for vulcanizing the rubber, or other vulcanizing agent, softening agent, tackifier, antioxidant, and ozone deterioration preventing agent. Anti-aging agent, Vulcanization accelerator, Vulcanization accelerator, Processing aid, Peeling agent, Tackifier, Peroxide, Zinc oxide, Stearic acid, Factis, Process oil, Aroma oil, Wax, etc. are necessary Additives corresponding to the above can be appropriately blended.
As the vulcanizing agent, an organic peroxide or a sulfur vulcanizing agent can be used. Examples of the organic peroxide include benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, t-butyl cumyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, 2,5-dimethyl-2, 5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne 3 or 1,3-bis (t-butylperoxypropyl) benzene or the like can be used. As the sulfur vulcanizing agent, for example, sulfur, sulfur chloride, morpholine disulfide, alkylphenol disulfide, polymer polysulfide, polysulfides and the like can be used.

Vulcanization accelerators include sulfenamide, thiazole, thiuram, thiourea, guanidine, dithiocarbamic acid, aldehyde-amine, aldehyde-ammonia, imidazoline, or xanthate vulcanization accelerators. Those containing at least one of them can be used.

As the anti-aging agent, amine-based, phenol-based and imidazole-based compounds, carbamic acid metal salts, waxes and the like can be appropriately selected and used.

An example of the manufacturing method is shown below.
(1) A raw rubber, a phenol-modified lignin resin, and optional components (excluding a vulcanizing agent and a vulcanization accelerator) are kneaded by a closed kneader such as a Banbury mixer, and contain a vulcanization system. No rubber composition is obtained. Here, the kneading conditions (temperature and time) vary depending on the kneader.
(2) A vulcanizing agent, a vulcanization accelerator and an optional component are added to the rubber composition obtained by the above (1) using rolls such as an open roll or the kneader, kneaded again, and added. A rubber composition containing a sulfur system is obtained.

<Hardened product of rubber composition and method for producing tire>
Next, a process for obtaining a cured product of a rubber composition and a tire will be described. The cured product and tire of the rubber composition can be obtained by molding the rubber composition. The molding method varies depending on the application and is not particularly limited. However, when molding using a mold, the produced rubber composition is molded using a mold equipped with a hydraulic press, and the rubber composition A cured product is obtained.

As an example, when the rubber composition of the present disclosure is used for a tire member, it is manufactured by a normal method. That is, the rubber composition is extruded into the shape of a tire member at an unvulcanized stage, and bonded together by a normal method on a tire molding machine to form an unvulcanized tire. The unvulcanized tire can be heated and pressurized in a vulcanizer to obtain a tire.

The molding temperature is preferably about 100 to 280 ° C., more preferably about 120 to 250 ° C., and further preferably about 130 to 230 ° C. If the molding temperature exceeds 230 ° C, the rubber may be deteriorated. If it is less than 100 ° C, molding may not be possible.

The present disclosure further relates to one or more of the following embodiments.
[A1] A phenol-modified lignin resin obtained by reacting lignin and / or a lignin derivative, a phenol, and an aldehyde in the presence of an acid,
The lignin and lignin derivative have a number average molecular weight of 100 to 5,000,
A phenol-modified lignin resin, wherein a molar ratio (F / P) of aldehydes (F), phenols and (P) in the reaction is 0.4 to 1.5.
[A2] A phenol-modified lignin resin obtained by reacting lignin and / or a lignin derivative, a phenol, and an aldehyde in the presence of an acid,
The lignin and lignin derivative have a weight average molecular weight of 100 to 5,000,
A phenol-modified lignin resin, wherein a molar ratio (F / P) of aldehydes (F), phenols and (P) in the reaction is 0.4 to 1.5.
[A3] The phenol-modified lignin resin according to [A1] or [A2], wherein the lignin derivative is a lignin derivative obtained by decomposing biomass.
[A4] The number average molecular weight of the lignin and / or lignin derivative is 100 to 5000, 4000 or less, 3000 or less, 2000 or less, 1500 or less, 1200 or less, or 1000 or less, and / or 200 or more. The phenol-modified lignin resin according to any one of [A1] to [A3], which is 250 or more, 300 or more, or 350 or more.
[A5] The molar ratio is 0.40 or more, 0.45 or more, or 0.50 or more, or 1.50 or less, 1.30 or less, or 1.20 or less from [A1] to [A4]. The phenol-modified lignin resin according to any one of the above.
[A6] The weight average molecular weight of the lignin and / or lignin derivative is 5000 or less, 4000 or less, 3500 or less, 3000 or less, 2500 or less, 2000 or less, or 1500 or less, and / or 100 or more, 200 or more, or 400. The phenol-modified lignin resin according to any one of [A1] to [A5].
[A7] The phenol-modified lignin resin according to any one of [A3] to [A6], wherein the biomass is lignocellulosic biomass.
[A8] The lignin derivative is a lignin derivative obtained by decomposing biomass at 150 to 400 ° C., 1 to 40 MPa and a treatment time of 8 hours or less in the presence of a solvent, from [A1] to [A7]. The phenol-modified lignin resin according to any one of the above.
[A9] The lignin derivative includes at least one selected from the group consisting of guaiacylpropane (ferulic acid), syringylpropane (sinapic acid), and 4-hydroxyphenylpropane (coumaric acid) represented by [A1 ] To the phenol-modified lignin resin according to any one of [A8].
[A10] The softening point is 85 ° C or higher, 90 ° C or higher, or 95 ° C or higher, 65 ° C or higher, 75 ° C or higher, or 85 ° C or higher, and 170 ° C or lower, 160 ° C or lower, or 150 ° C or lower. The phenol-modified lignin resin according to any one of [A1] to [A9].
[A11] The phenol-modified lignin resin according to any one of [A1] to [A10], which has a weight average molecular weight of 1000 or more and 1500 or more and / or 10,000 or less, 8000 or less or 6000 or less.
[A12] The number average molecular weight is 300 or more, 400 or more, 500 or more, or 550 or more, and / or 4000 or less, 2000 or less, 1500 or less, 1200 or less, 1100 or less, or 1000 or less. The phenol-modified lignin resin according to any one of [A11].
[B1] A method for producing a phenol-modified lignin resin comprising reacting lignin and / or a lignin derivative, a phenol and an aldehyde in the presence of an acid,
The lignin and lignin derivative have a number average molecular weight of 100 to 5,000,
The production method wherein the molar ratio (F / P) of aldehydes (F), phenols and (P) in the reaction is 0.4 to 1.5.
[B2] A method for producing a phenol-modified lignin resin comprising reacting lignin and / or a lignin derivative, a phenol and an aldehyde in the presence of an acid,
The lignin and lignin derivative have a weight average molecular weight of 100 to 5,000,
The production method wherein the molar ratio (F / P) of aldehydes (F), phenols and (P) in the reaction is 0.4 to 1.5.
[B3] The production method according to [B1] or [B2], wherein the lignin derivative is a lignin derivative obtained by decomposing biomass.
[B4] The number average molecular weight of the lignin and / or lignin derivative is 100 to 5000, 4000 or less, 3000 or less, 2000 or less, 1500 or less, 1200 or less, or 1000 or less, and / or 200 or more. The production method according to any one of [B1] to [B3], which is 250 or more, 300 or more, or 350 or more.
[B5] The molar ratio is 0.40 or more, 0.45 or more, or 0.50 or more, or 1.50 or less, 1.30 or less, or 1.20 or less from [B1] to [B4]. The manufacturing method in any one.
[B6] The weight average molecular weight of the lignin and / or lignin derivative is 5000 or less, 4000 or less, 3500 or less, 3000 or less, 2500 or less, 2000 or less or 1500 or less, and / or 100 or more, 200 or more, or 400. The production method according to any one of [B1] to [B5].
[B7] The method according to any one of [B3] to [B6], wherein the biomass is lignocellulosic biomass.
[B8] The lignin derivative is a lignin derivative obtained by decomposing biomass at 150 to 400 ° C., 1 to 40 MPa, and a treatment time of 8 hours or less in the presence of a solvent, from [B1] to [B7]. The manufacturing method in any one.
[B9] The lignin derivative includes at least one selected from the group consisting of guaiacylpropane (ferulic acid), syringylpropane (sinapic acid), and 4-hydroxyphenylpropane (coumaric acid) represented by [B1 ] To [B8].
[B10] The addition amount of the phenols is 10 parts by weight or more, 20 parts by weight or more, or 30 parts by weight or more, and 500 parts by weight or less, 300 parts by weight or less or 200 parts by weight with respect to 100 parts by weight of lignins. The production method according to any one of [B1] to [B9], which is not more than part.
[B11] The acid is an organic acid or an inorganic acid, and the organic acid is acetic acid, formic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, benzoic acid, salicylic acid, sulfonic acid, phenolsulfonic acid. And the inorganic acid is selected from the group consisting of hydrochloric acid, sulfuric acid, sulfuric acid ester, phosphoric acid, phosphoric acid ester, etc., and any one of [B1] to [B10] The manufacturing method as described.
[B12] The production method according to any one of [B1] to [B11], wherein the phenol-modified lignin resin according to any one of [A1] to [A12] is produced.
[C1] A resin composition comprising the phenol-modified lignin resin according to any one of [A1] to [A12].
[D1] A phenol-modified lignin resin for rubber reinforcement, which is obtained by reacting a lignin derivative, a phenol or a phenol derivative, and a mixture containing aldehydes.
[D2] The phenol-modified lignin resin according to [D1], wherein the phenol-modified lignin resin is obtained by a reaction containing a lignin derivative, a phenol, and an aldehyde in the presence of an acid.
[D3] The phenol-modified lignin resin according to [D2], wherein the acid includes an organic acid.
[D4] The phenol-modified lignin resin according to any one of [D1] to [D5], wherein the phenol-modified lignin resin has a number average molecular weight of 200 or more and 5000 or less.
[D5] The phenol-modified lignin resin according to any one of [D1] to [D4], wherein a softening point of the phenol-modified lignin resin is 60 ° C or higher and 160 ° C or lower.
[D6] The phenol-modified lignin resin according to any one of [D1] to [D5], wherein the number average molecular weight of the lignin derivative is 200 or more and 5000 or less.
[D7] The molar ratio (F / (P + L)) of the aldehydes (F) and the phenol or the phenol derivative (P) and the lignin derivative (L) in the resin is 0.01 or more and 5.0 or less. The phenol-modified lignin resin according to any one of [D1] to [D6].
[E1] A resin composition comprising the phenol-modified lignin resin according to any one of [D1] to [D7].
[F1] A rubber composition comprising the phenol-modified lignin resin according to any one of [D1] to [D7] and a diene rubber.
[F2] The rubber composition according to [F1], wherein the rubber composition contains a filler.
[F3] The rubber composition according to [F1] or [F2], wherein the filler contains at least one selected from the group consisting of carbon black, silica, alumina, and cellulose fiber.
[G1] A cured product obtained by curing the rubber composition according to any one of [F1] to [F3].

Hereinafter, the present disclosure will be described based on the following examples and comparative examples, but the present disclosure is not limited thereto. Further, “parts” described herein indicate “parts by weight”, and “%” indicates “% by weight”.

[Preparation of lignin derivatives]
(Lignin derivative 1)
A lignin derivative was prepared from cedar by the following procedure.
First, 100 parts by weight of cedar wood flour (60 mesh under) and 567 parts by weight of a solvent made of pure water were mixed and introduced into a 1 L autoclave. Then, while stirring the contents at 300 rpm, as a pretreatment, the mixture was stirred for 15 minutes at room temperature, and after thoroughly blending the cedar wood flour and the solvent, it was treated at 300 ° C. and 9 MPa for 60 minutes to decompose the cedar wood flour. did.
Subsequently, the obtained decomposition product was filtered, and the solid component separated by filtration was recovered.
Next, the obtained solid component was immersed in 250 parts of acetone for 12 hours. This was filtered to recover acetone-soluble components.
Next, acetone was distilled off from the acetone-soluble component and dried to obtain 15.2 parts by weight of a lignin derivative.
The physical properties of the obtained lignin derivative were measured by the following methods, and the obtained results are shown in Table 1.

(Lignin derivative 2)
A lignin derivative was prepared in the same manner as the lignin derivative 1 except that the treatment temperature was 230 ° C. and the treatment pressure was 3 MPa.

(Lignin derivative 3)
A lignin derivative was prepared in the same manner as lignin derivative 1 except that 283 parts by weight of solvent and 283 parts by weight of acetone were used as the solvent, the processing temperature was 230 ° C., and the processing pressure was 5 MPa.

(Lignin derivative 4)
A lignin derivative was prepared in the same manner as the lignin derivative 1 except that beech was used instead of cedar as a raw material.

(Lignin derivative 5)
A lignin derivative was prepared in the same manner as the lignin derivative 1 except that beech was used instead of rice straw as a raw material.

Example 1
After adding the lignin derivative 1 to the three-necked flask, phenol (manufactured by Wako Pure Chemical Industries, Ltd.) was added at the ratio shown in Table 2 below, and the mixture was stirred at about 120 ° C. for 20 minutes after the temperature was raised. Thereafter, oxalic acid was added at a ratio of 1.8 parts by weight to lignin and stirred. Next, 37% formaldehyde was added successively so as to have the ratio shown in Table 2 below, and after completion of the sequential addition, the mixture was stirred at 100 ° C. for 1 hour. Next, vacuum distillation was performed while raising the temperature, water and unreacted phenol were distilled off, and when the residual phenol was 5% or less, the product was taken out to obtain a phenol-modified lignin resin (yield: 62% FP reaction rate: 0.45).
The sulfuric acid content, lignin ratio, number average molecular weight, weight average molecular weight, and softening point in the obtained phenol-modified lignin resin were measured by the following methods, and the results are shown in Table 2 below.

(Example 2)
A phenol-modified lignin resin was obtained in the same manner as in Example 1 except that the formaldehyde was changed to the ratio shown in Table 2 below.

Example 3
A phenol-modified lignin resin was obtained in the same manner as in Example 1 except that the ratio of phenol and formaldehyde was changed to those shown in Table 2 below.

Example 4
A phenol-modified lignin resin was obtained in the same manner as in Example 1 except that the ratio of phenol and formaldehyde was changed to those shown in Table 2 below.

(Example 5)
A phenol-modified lignin resin was obtained in the same manner as in Example 1 except that the ratio of phenol and formaldehyde was changed to those shown in Table 2 below.

(Example 6)
A phenol-modified lignin resin was obtained in the same manner as in Example 1 except that the lignin derivative 2 was used and the ratios of phenol and formaldehyde were as shown in Table 2 below.

(Example 7)
A phenol-modified lignin resin was obtained in the same manner as in Example 1 except that the lignin derivative 3 was used and the ratio of phenol and formaldehyde was as shown in Table 2 below.

(Example 8)
Using lignin derivative 4, a phenol-modified lignin resin was obtained in the same manner as in Example 4.

Example 9
Using lignin derivative 5, a phenol-modified lignin resin was obtained in the same manner as in Example 4.

(Comparative Example 1)
A phenol-modified lignin resin was obtained in the same manner as in Example 1 except that the formaldehyde was changed to the ratio shown in Table 2 below.

(Comparative Example 2)
Example 1 except that high molecular weight lignin (weight average molecular weight: 7700, number average molecular weight: 1600, sulfuric acid content: 7.1, softening point: 175 ° C.) was used, and the ratio of formaldehyde was as shown in Table 2 below. Similarly, a phenol-modified lignin resin was prepared. However, since it gelled during preparation, it could not be used as a resin, and an accurate molecular weight could not be measured.

[Measurement method of physical properties]
<Sulfuric acid content>
Raw material lignin derivative 1-5 or 1.0 g of high molecular weight lignin and ultrapure water are placed in an extraction container and sealed, extracted with hot water at 125 ° C. for 20 hours, and after centrifugation, the supernatant is taken and did. The test solution and standard solution were introduced into an ion chromatograph (Dionex ICS-2000 type, DX-320 ion chromatograph), and the concentration of each ion was determined by the calibration curve method and converted to the concentration in the sample.
<Number average molecular weight and weight average molecular weight>
The number average molecular weight and the weight average molecular weight were measured using gel permeation chromatography. A measurement sample was prepared by dissolving a lignin derivative or a phenol-modified lignin in tetrahydrofuran. Measurement sample in GPC system “HLC-8320GPC (manufactured by Tosoh)”, which is an organic general-purpose column packed with styrene polymer filler, “TSKgelGMHXL (manufactured by Tosoh)” and “G2000HXL (manufactured by Tosoh)” Tetrahydrofuran as an eluent was developed at 1.0 mL / min at 40 ° C. into which 200 μL had been injected, and the retention time was measured using differential refractive index (RI) and ultraviolet absorbance (UV). The number average molecular weight and weight average molecular weight of the lignin derivative or phenol-modified lignin were calculated from a calibration curve showing the relationship between the retention time and molecular weight of standard polystyrene prepared separately.
<Softening point>
The softening point was measured according to JIS K2207 using a ring and ball softening point tester (ASP-MG2 type manufactured by Meltech Co., Ltd.).
<Yield>
It was calculated by the following formula from the yield of the phenol-modified lignin resin and the charged amount of raw material (excluding the solvent). The yield of the phenol-modified lignin resin was calculated by dividing the weight of the reaction vessel before filling the raw material into the reaction vessel from the weight of the reaction vessel after carrying out the polymerization after filling the raw material.
Yield (%) = (Yield of phenol-modified lignin resin) / (Feed amount of raw material (excluding solvent)) × 100
<FP reaction rate>
The yield was calculated from the following formula from the yield of the phenol-modified lignin resin, the charged amount of lignin (W _L ), the charged amount of phenol (W _P ), and the charged amount of formalin (W _f ). FP reaction rate (%) = (yield−W _L ) / (W _P + W _f ) × 100
<Lignin rate>
Assuming that the mass of lignin did not change before and after denaturation, it was calculated by the following formula.
Lignin rate (%) = (Lignin charge) / (Yield of phenol-modified lignin resin) × 100

[Evaluation of resin]
The phenol-modified lignin resins of Examples 1 to 9 and Comparative Example 1 were evaluated as follows. As Comparative Example 3, the same evaluation was performed using the lignin derivative prepared in Example 1 instead of the phenol-modified lignin resin. The results are shown in Table 2.
<Curing time>
A resin composition was prepared by adding 15 parts by mass of hexamethylenetetramine to 100 parts by mass of a phenol-modified lignin resin or lignin derivative at room temperature, and pulverizing and mixing. Using a viscoelastic device (Rheometer MCR301 manufactured by Anton Paar), The resin composition thus formed into tablets was subjected to time-dependent shear direction viscoelasticity measurement under the conditions of 1% strain, vibration frequency 1 Hz, and 175 ° C. The time required to reach a storage elastic modulus of 90% of the storage elastic modulus after 30 minutes of measurement was defined as a curing time (T90).
<Curing degree>
15 parts by mass of hexamethylenetetramine was added at room temperature to 100 parts by mass of a phenol-modified lignin resin or lignin derivative, mixed by pulverization, and then placed in a heat oven and heated at 175 ° C. for 10 minutes to obtain a cured product. The obtained cured product was pulverized, and the pulverized cured product placed in a cylindrical filter paper was immersed in boiling acetone solvent and boiled for 1 hour using a rapid solvent extraction device “Soctest SER148 / 6 (manufactured by Actac)”. Next, the cylindrical filter paper was pulled up from the acetone solvent, and acetone cooled down and liquefied at the upper part of the apparatus was dropped onto the sample in the cylindrical filter paper, and rinsed for 1 hour. The obtained acetone extract was air-dried for 12 hours and further dried under reduced pressure at 50 ° C. for 2 hours. The weight of the extracted solid obtained by drying was defined as the weight of acetone eluted. Using the obtained acetone elution weight, the degree of cure was calculated by the following formula.
Curing degree (%) = (cured material weight−acetone elution weight) / cured material weight × 100

[Evaluation of molded resin]
Resin molded bodies were prepared using the phenol-modified lignin resins of Examples 1 to 9, Comparative Examples 1 and 2, and the lignin derivative 1 (Comparative Example 3), and the appearance and bending strength were evaluated by the following methods. The results are shown in Table 2. The phenol-modified lignin resin of Comparative Example 2 could not be molded into a molded product.
<Preparation of resin composition>
15 parts by mass of hexamethylenetetramine was added to phenol-modified lignin resin or 100 parts by mass of lignin at room temperature, and pulverized and mixed to prepare a lignin resin composition.
<Preparation of resin molding>
The glass fiber (glass milled fiber, manufactured by Nitto Boseki Co., Ltd., standard fiber diameter 10 ± 1.5 μm, average fiber length 90 μm) is mixed with the lignin resin composition in a mixing ratio of 50.5 wt. % Was added. The mixture was kneaded at 90 ° C. and 50 rpm in a lab plast mill, and the kneaded product was compression molded at 175 ° C. for 3 minutes to obtain a resin molded body having a width of 10 mm, a length of 100 mm, and a height of 4 mm.
<Appearance>
About the obtained resin molding, the external appearance was confirmed visually and evaluated. The appearance evaluation criteria are as follows.
Evaluation criteria ○: The surface of the molded product is smooth, and the surface of the molded product has no irregularities that can be seen with the naked eye, or has 1 to 2 strains, wrinkles, and spots.
Δ: Unevenness that can be seen with the naked eye is observed on the surface of the molded product, or there are 3 to 5 strains, wrinkles, and spots.
X: Remarkable unevenness | corrugation which can be recognized with the naked eye is recognized on the surface of a molded article, or there are six or more distortions, wrinkles, and spots.
<Bending strength>
The bending strength was calculated | required based on JISK6911 using the resin molding. The bending strength was calculated | required based on JISK6911 using the resin molding. Specifically, a three-point bending test was performed using a precision universal testing machine (Autograph AG-Xplus, manufactured by Shimadzu Corporation) with a load of 2 mm / min.

As shown in Table 2, Examples 1 to 9 had higher yields than Comparative Example 1. In addition, the phenol-modified lignin resins of Examples 1 to 9 had a higher softening point than that of Comparative Example 1.

It can be evaluated that the shorter the curing time at 175 ° C., the higher the curability. As shown in Table 2, all of the phenol-modified lignin resins of Examples 1 to 9 have a curing time of 1150 seconds or less, of which Examples 2 to 9 are 900 seconds or less, and Examples 4, 7 and 8 Was about 500 seconds or less, and both were curable in a short time as compared with the comparative example. Moreover, since it can be said that the high degree of curing indicates that the crosslinking further progressed by heating under certain conditions to form a crosslinked body insoluble in acetone, the higher the degree of curing, the higher the curability. it can. As shown in Table 2, the phenol-modified lignin resins of Examples 1 to 9 all had a degree of cure exceeding 85%, and in particular, Examples 1, 4 and 6 were 95% or more, which was higher than the comparative example. Therefore, it can be evaluated that the phenol-modified lignin resins of Examples 1 to 9 have higher curability than the comparative examples.
In addition, the resin moldings prepared using the phenol-modified lignin resins of Examples 1 to 9 all had higher bending strength than the molding of Comparative Example 1. In particular, Examples 4 to 9 have a higher lignin ratio than Comparative Example 1, that is, they have a lower amount of phenols and aldehydes reacted with lignin than Comparative Example 1, but are less than Comparative Example 1. High bending strength was obtained. In addition, the resin moldings prepared using the phenol-modified lignin resins of Examples 1 to 9 were all excellent in moldability and showed a good appearance as compared with the moldings of Comparative Example 1.

(Example 11)
(1) Extraction of lignin derivative 100 parts of cedar wood flour (60 mesh under) and 400 parts of a solvent consisting of pure water were mixed and introduced into a 1 L autoclave. Then, while stirring the contents at 300 rpm, as a pretreatment, the mixture was stirred for 15 minutes at room temperature. After sufficiently blending the cedar wood flour and the solvent, it was treated at 300 ° C. and 10 MPa for 60 minutes to obtain cedar wood flour. Disassembled.
Subsequently, the obtained decomposition product was filtered, and the solid component separated by filtration was recovered.
Next, the obtained solid component was immersed in 250 parts of acetone for 12 hours. This was filtered to recover acetone-soluble components.
Subsequently, 15.5 parts of lignin derivative (A) was obtained by distilling acetone off from the said acetone soluble component, and drying. The number average molecular weight was 420 and the softening point was 107 ° C.

(2) Preparation of phenol-modified lignin resin After the prepared lignin derivative was added to a three-necked flask, phenol (manufactured by Wako Pure Chemical Industries, Ltd.) was added at the rate shown in Table 3 below, followed by stirring at about 120 ° C for 20 minutes. did. Thereafter, oxalic acid was added at a ratio of 1.8 parts by weight to lignin and stirred. Next, 37% formaldehyde was added successively so as to have the ratio shown in Table 1 below, and stirred at 100 ° C. for 1 hour after the addition. Next, vacuum distillation was performed while raising the temperature, water and unreacted phenol were distilled off, and when the residual phenol was 5% or less, the product was taken out to obtain a phenol-modified lignin resin (yield: 62% ). The lignin ratio, number average molecular weight, weight average molecular weight, and softening point of the obtained phenol-modified lignin resin were measured by the following methods, and the results are shown in Table 3 below.

(3) Preparation of rubber composition 100 parts of phenol-modified lignin resin, 500 parts of natural rubber compound, 350 parts of carbon black, 10 parts of hexamethylenetetramine as a resin crosslinking agent, 15 parts of sulfur as a vulcanizing agent, MSA as a vulcanization accelerator A rubber composition was obtained by kneading 7.5 parts of -G, 25 parts of zinc oxide as a vulcanization accelerator, 10 parts of stearic acid as a release agent, and heating a Banbury mixer at 100 ° C.

Example 12
In the production of the phenol-modified lignin resin, the same as Example 11 except that the modified formulation was changed as shown in Table 3.

(Example 13)
In the production of the phenol-modified lignin resin, the same as Example 11 except that the modified formulation was changed as shown in Table 3.

(Example 14)
In the production of the phenol-modified lignin resin, the same as Example 11 except that the modified formulation was changed as shown in Table 3.

(Example 15)
In the production of the phenol-modified lignin resin, the same as Example 11 except that the modified formulation was changed as shown in Table 3.

(Example 16)
In the extraction of the lignin derivative, the solvent and conditions for the decomposition treatment were as shown in Table 3, and the modified prescription was changed in the production of the phenol resin, as in Example 11. The lignin derivative had a number average molecular weight of 670 and a softening point of 123 ° C.

(Example 17)
In the extraction of the lignin derivative, the same as Example 11 except that the raw material was changed to beech instead of cedar wood flour, and the modified prescription was changed in the production of phenol resin. The lignin derivative had a number average molecular weight of 440 and a softening point of 113 ° C.

(Example 18)
In the extraction of the lignin derivative, the same as Example 11 except that the raw material was changed to rice straw instead of cedar wood flour, and the modified prescription was changed in the production of phenol resin. The lignin derivative had a number average molecular weight of 350 and a softening point of 98 ° C.

(Example 19)
The production of the rubber composition was the same as Example 12 except that 280 parts by mass of carbon black and 70 parts by mass of silica were added, and 5 parts of a silica coupling agent was further added.

(Comparative Example 11)
A rubber composition was obtained according to Example 11 without using a phenol-modified lignin resin.

(Comparative Example 12)
A rubber composition was obtained according to Example 11 except that the lignin derivative obtained in the example was used instead of the phenol-modified lignin resin.

(Comparative Example 13)
The same as Comparative Example 11 except that 100 parts by mass of phenol novolac resin was used instead of phenol-modified lignin resin.

Using the rubber compositions obtained in the above examples and comparative examples, various rubber compounding compositions heated and kneaded in the compounding (parts) shown in Table 3 were vulcanized with a hydraulic press at 160 ° C. for 20 minutes, and then thickened. A vulcanized rubber sheet having a thickness of 2 mm was produced. The evaluation results are shown in Table 1.

Below, the various raw materials used in the Example and the comparative example are demonstrated.
Natural rubber: Tochi made RSS3
Curing agent: Hexamethylenetetramine carbon black: manufactured by Mitsubishi Chemical Corporation, HAF
Silica: manufactured by Evonik, Ultrasil VN3 (BET specific surface area: 175 m 2 / g)
Silane coupling agent: Si-69, manufactured by Evonik
Zinc oxide: Stearic acid manufactured by Sakai Chemical Industry Co., Ltd .: NOF Beads Stearic Acid YR
Sulfur: manufactured by Hosoi Chemical Co., Ltd., fine sulfur vulcanization accelerator: manufactured by Ouchi Shinsei Chemical Co., Ltd., MSA-G
Novolac type phenolic resin: Sumitomo Bakelite, PR-50731

[Measurement method of resin properties]
<Number average molecular weight and weight average molecular weight>
Measurements were made as described above.
<Softening point>
Measurements were made as described above.
<Lignin rate>
Measurements were made as described above.

[Measurement method of rubber properties]
(A) Tensile stress at break / elongation at break In accordance with JIS K6251, a tensile rate of 50 mm / min was measured using a strograph manufactured by Toyo Seiki Co., Ltd.
(B) Storage elastic modulus, tan δ
The storage elastic modulus at 30 ° C. and tan δ at 60 ° C. were measured using a dynamic viscoelasticity measuring device manufactured by TA Instruments under the condition of 2% dynamic strain.
A large value of the reciprocal of tan δ at 60 ° C. means that tan δ of the viscoelastic characteristics is small, which means that thermal energy generated by repeated deformation can be suppressed and hysteresis loss is small. A small hysteresis loss means that fuel efficiency can be improved in the case of a tire.
The results are shown in Table 3 as an index representing the values of other Examples and Comparative Examples as ratios, with Comparative Example 11 being 100.

As is clear from Table 3, the cured product of the rubber composition obtained in each example is excellent in the reciprocal of the tan δ value at 60 ° C., which indicates the low hysteresis loss of the rubber, and the elastic modulus. While maintaining the elongation at the time of cutting, the decrease in the tensile stress at the time of cutting was suppressed. That is, the rubber composition obtained in each example was excellent in the fuel economy and rubber rigidity of rubber parts and in the balance of mechanical strength. Furthermore, by using the phenol-modified lignin resin according to the present disclosure, the above-described excellent characteristics and a high degree of plant origin can be achieved at a high level, so that the environmental burden can be reduced.

In one or a plurality of embodiments, the rubber composition of the present disclosure is suitably used for applications requiring excellent low hysteresis loss, excellent elastic modulus, tensile stress at break and elongation at break, particularly tire applications. Can do.

Claims

A phenol-modified lignin resin obtained by reacting lignins, phenols, and aldehydes in the presence of an acid,
The number average molecular weight of the lignin is 100 or more and 5000 or less,
A phenol-modified lignin resin having a molar ratio (F / P) of aldehydes (F), phenols and (P) in the reaction of 0.4 to 1.5.
The phenol-modified lignin resin according to claim 1, wherein the lignin is a lignin derivative obtained by decomposing biomass.
The phenol-modified lignin resin according to claim 1 or 2, wherein the lignin has a weight average molecular weight of 100 or more and 5000 or less.
A phenol-modified lignin resin for rubber reinforcement,
A phenol-modified lignin resin obtained by reacting a mixture containing lignins, phenols and aldehydes.
The phenol-modified lignin resin according to claim 4, wherein a mixture containing lignins, phenols and aldehydes is obtained by a reaction in the presence of an acid.
The phenol-modified lignin resin according to any one of claims 1 to 3, wherein the acid contains an organic acid.
The phenol-modified lignin resin according to any one of claims 1 to 6, wherein the phenol-modified lignin resin has a number average molecular weight of 200 or more and 5000 or less.
The phenol-modified lignin resin according to any one of claims 1 to 7, wherein a softening point of the phenol-modified lignin resin is 60 ° C or higher and 160 ° C or lower.
The phenol-modified lignin resin according to any one of claims 1 to 8, wherein the lignin has a number average molecular weight of 200 or more and 5000 or less.
The molar ratio (F / (P + L)) of aldehydes (F), phenols (P) and lignins (L) in the resin is 0.01 or more and 5.0 or less. The phenol-modified lignin resin according to claim 1.
A resin composition comprising the phenol-modified lignin resin according to any one of claims 1 to 10.
A rubber composition comprising the phenol-modified lignin resin according to any one of claims 1 to 10 and a diene rubber.
The rubber composition according to claim 12, wherein the rubber composition contains a filler.
The rubber composition according to claim 12 or 13, wherein the filler contains at least one selected from the group consisting of carbon black, silica, alumina, and cellulose fiber.
A cured product obtained by curing the rubber composition according to claim 12.
A process for producing a phenol-modified lignin resin comprising reacting lignins, phenols and aldehydes in the presence of an acid,
The number average molecular weight of the lignin is 100 or more and 5000 or less,
The manufacturing method whose molar ratio (F / P) of aldehydes (F), phenols, and (P) in the said reaction is 0.4-1.5.
The production method according to claim 16, wherein the amount of the phenol added is 10 to 200 parts by weight with respect to 100 parts by weight of the lignin and lignin derivative.