WO2018139074A1

WO2018139074A1 - Novolac type phenolic resin, resin composition and method for producing novolac type phenolic resin

Info

Publication number: WO2018139074A1
Application number: PCT/JP2017/044286
Authority: WO
Inventors: 康典大橋; 霖周; 麻衣子山本; 勇希谷口; 木村　肇; 大塚　恵子; 松本　明博
Original assignee: ハリマ化成株式会社; 地方独立行政法人大阪産業技術研究所
Priority date: 2017-01-24
Filing date: 2017-12-11
Publication date: 2018-08-02
Also published as: JP2020055888A

Abstract

This novolac type phenolic resin is a reaction product that is obtained by reacting a lignin that has an aliphatic hydroxyl group in each molecule, a phenol and an aldehyde in the presence of an acid catalyst; and the content ratio of the aliphatic hydroxyl group in the lignin is from 0.5% by mass to 7.0% by mass (inclusive) relative to the total mass of the lignin.

Description

NOVOLAC TYPE PHENOL RESIN, RESIN COMPOSITION AND METHOD FOR PRODUCING NOVOLAC TYPE PHENOL RESIN

TECHNICAL FIELD The present invention relates to a novolac type phenol resin, a resin composition, and a method for producing a novolac type phenol resin. More specifically, the present invention relates to a novolac type phenol resin, a resin composition containing the novolac type phenol resin, and the novolac type phenol. The present invention relates to a method for producing a resin.

Conventionally, thermosetting resins have been widely used in various industrial fields such as electric parts, automobile parts, building materials, and daily necessities. In particular, novolac type phenolic resins are widely used as molding materials because they are excellent in electrical insulation, heat resistance, mechanical properties, moldability, and the like.

The novolac type phenol resin can be obtained by reacting phenols and aldehydes in the presence of an acid catalyst. On the other hand, in recent years, from the viewpoint of protecting the global environment, etc., it has been required to reduce the amount of petroleum resources used, and the use of plant-derived raw materials instead of petroleum resources has been studied.

As such a plant-derived raw material, lignin has attracted attention. Specifically, as a novolac type phenol resin obtained using lignin, for example, lignin, phenol or a phenol derivative, and aldehydes, A lignin-modified novolac type phenolic resin obtained by reacting in the presence of an organic acid has been proposed. (See Patent Document 1 below).

JP 2008-156601 A

On the other hand, Patent Document 1 describes that as lignin, craft lignin obtained from raw materials such as wood and grassy materials, lignin sulfonic acid and the like can be used without limitation. For example, lignin sulfonic acid and the like can be used. When used, the reactivity with phenol and aldehydes is inferior, and the productivity (resin yield, production rate, etc.) of the lignin-modified novolac type phenol resin is inferior.

An object of the present invention is to provide a novolak type phenol resin excellent in productivity, a resin composition containing the novolac type phenol resin, and a method for producing the novolac type phenol resin.

The present invention [1] is a reaction product of a lignin having an aliphatic hydroxyl group in the molecule, a phenol, and an aldehyde under an acid catalyst, and the content of the aliphatic hydroxyl group in the lignin is: A novolac-type phenol resin is contained in an amount of 0.5% by mass or more and 7.0% by mass or less based on the total amount of the lignin.

The present invention [2] includes the novolak type phenol resin according to the above [1], which is a reaction product of a lignin-phenol composition containing the reaction product of the lignin and the phenols and the aldehyde. It is out.

[3] The present invention [3] includes the novolac phenol resin according to the above [1] or [2], wherein the lignin is a lignin modified with acetic acid.

The present invention [4] includes a resin composition containing the novolac type phenol resin according to any one of the above [1] to [3].

The present invention [5] includes a step of reacting a lignin having an aliphatic hydroxyl group in the molecule, a phenol, and an aldehyde in the presence of an acid catalyst, wherein the content of the aliphatic hydroxyl group in the lignin is as described above. A method for producing a novolac-type phenol resin, which is 0.5% by mass or more and 7.0% by mass or less with respect to the total amount of lignin, is included.

The novolak-type phenolic resin and resin composition of the present invention are excellent in productivity (resin yield, production rate, etc.) because lignin having an aliphatic hydroxyl group in the molecule at a predetermined ratio is used as a raw material.

Further, according to the method for producing a novolac type phenol resin of the present invention, a novolac type phenol resin can be obtained with high productivity.

The novolac type phenol resin of the present invention can be obtained by reacting lignin having an aliphatic hydroxyl group (described later) in the molecule, phenols and aldehydes in the presence of an acid catalyst. That is, the novolak type phenol resin of the present invention is a reaction product of lignin having an aliphatic hydroxyl group (described later) in the molecule, phenols, and aldehydes.

Lignin is a high molecular phenolic compound having a basic skeleton such as guaiacyl lignin (G type), syringyl lignin (S type), p-hydroxyphenyl lignin (H type) and the like.

More specifically, lignin is classified according to, for example, the type of plant used as a raw material, and specific examples include woody plant-derived lignin and herbaceous plant-derived lignin.

Examples of woody plant-derived lignin include coniferous lignin contained in conifers (eg, cedar), for example, broadleaf lignin contained in broadleaf trees. Such woody plant-derived lignin does not contain lignin having H-type basic skeleton, for example, conifer lignin has G-type basic skeleton, and hardwood lignin has G-type and S-type basic skeleton. Yes.

Examples of the herbaceous plant-derived lignin include, for example, rice-based lignin contained in Gramineae plants, and more specifically, wheat straw lignin contained in wheat straw, rice straw lignin contained in rice straw, and corn. Examples include corn lignin and bamboo lignin contained in bamboo. Such herbaceous plant-derived lignin has all of H-type, G-type and S-type as the basic skeleton.

These lignins can be used alone or in combination of two or more.

The lignin is preferably a herbaceous plant-derived lignin, more preferably a herbaceous plant-derived lignin derived from straw, or a herbaceous plant-derived lignin derived from corn.

Further, as lignin, from the viewpoint of reactivity, it is preferable to contain an H-type basic skeleton in a proportion of 3% by mass or more, more preferably 9% by mass or more, and still more preferably 14% by mass or more. It is done.

Such lignin is contained in waste liquid (black liquor) discharged when pulp is produced from a plant by a known method such as an alkali method (soda method), a sulfurous acid method, or a kraft method. More specifically, the waste liquid (black liquor) discharged in the alkali method contains alkali lignin, and the waste liquid (black liquor) discharged in the sulfurous acid method contains sulfite lignin. The discharged waste liquid (black liquor) contains kraft lignin.

In addition to the above, examples of lignin include acid-modified lignin obtained by modifying lignin with an acid (such as a carboxylic acid), and explosion lignin obtained by treating a plant with an explosion method.

The lignin is preferably an acid-modified lignin, more preferably a carboxylic acid-modified lignin.

In the carboxylic acid-modified lignin, examples of the carboxylic acid include a carboxylic acid having one carboxy group (hereinafter, sometimes referred to as a monofunctional carboxylic acid). Functional carboxylic acid, unsaturated aliphatic monofunctional carboxylic acid, aromatic monofunctional carboxylic acid and the like can be mentioned.

Examples of the saturated aliphatic monofunctional carboxylic acid include acetic acid, propionic acid, butyric acid, lauric acid and the like.

Examples of the unsaturated aliphatic monofunctional carboxylic acid include acrylic acid, methacrylic acid, and linoleic acid.

Examples of the aromatic monofunctional carboxylic acid include benzoic acid, 2-phenoxybenzoic acid, and 4-methylbenzoic acid.

These carboxylic acids can be used alone or in combination of two or more.

The carboxylic acid is preferably a saturated aliphatic monofunctional carboxylic acid, more preferably acetic acid (in other words, lignin modified with acetic acid is used as lignin). If the carboxylic acid is used, a carboxylic acid-modified lignin can be easily obtained, and the carboxylic acid-modified lignin obtained has a relatively high solubility in an organic solvent and has a melting temperature as described later. Since it is relatively low temperature (about 100 to 200 ° C.), it is excellent in handleability.

Also, the carboxylic acid can be prepared as an aqueous solution. In such a case, the concentration of the carboxylic acid aqueous solution is not particularly limited and is set as appropriate.

The production method of the carboxylic acid-modified lignin is not particularly limited, and can conform to a known method.

Specifically, for example, a plant material (for example, a conifer, a broadleaf tree, a gramineous plant, etc.) that is a raw material for lignin is digested with a carboxylic acid (preferably acetic acid). A carboxylic acid-modified lignin can be obtained as a pulp waste liquid by modifying with a carboxylic acid.

The cooking method is not particularly limited. For example, a plant material that is a raw material for lignin is mixed with a carboxylic acid and an inorganic acid (for example, hydrochloric acid, sulfuric acid, etc.) and reacted.

The mixing ratio of the carboxylic acid is such that the carboxylic acid (100% conversion) is, for example, 500 parts by mass or more, preferably 900 parts by mass or more, for example, 30000 with respect to 100 parts by mass of the plant material that is the raw material for lignin. It is 1 part by mass or less, preferably 15000 parts by mass or less.

The blending ratio of the inorganic acid is, for example, 0.01 parts by mass or more, preferably 0.05 parts by mass or more with respect to 100 parts by mass of the plant material that is the raw material for lignin. For example, it is 10 parts by mass or less, preferably 5 parts by mass or less.

As reaction conditions, under atmospheric pressure, the reaction temperature is, for example, 30 ° C. or more, preferably 50 ° C. or more, for example, 400 ° C. or less, preferably 250 ° C. or less. The reaction time is, for example, 0.5 hours or more, preferably 1 hour or more, for example, 20 hours or less, preferably 10 hours or less.

By such cooking, pulp is obtained and carboxylic acid-modified lignin is obtained as a pulp waste liquid.

Next, in this method, the pulp is separated by a known separation method such as filtration, and the filtrate (pulp waste liquid) is recovered. If necessary, the unreacted carboxylic acid is known using, for example, a rotary evaporator, vacuum distillation or the like. It is removed (distilled off) by the method. Thereafter, a large excess of water is added to precipitate the carboxylic acid-modified lignin, followed by filtration to recover the carboxylic acid-modified lignin as a solid content.

Further, the method for obtaining the carboxylic acid-modified lignin is not limited to the above. For example, lignin not modified with carboxylic acid (for example, the above alkaline lignin, the above sulfite lignin, the above kraft lignin, etc. (hereinafter referred to as unmodified lignin) ) And a carboxylic acid can be used to modify an aliphatic hydroxyl group (described later) of lignin with a carboxylic acid to obtain a carboxylic acid-modified lignin.

In such a method, the native lignin is preferably powdered native lignin.

The average particle size of the powdered unmodified lignin is, for example, 0.1 μm or more, preferably 5 μm or more, for example, 1000 μm or less, preferably 500 μm or less.

If the average particle diameter is in the above range, aggregation of the unmodified lignin can be suppressed and the unmodified lignin can be favorably dispersed in the carboxylic acid.

The powdered unmodified lignin can be obtained by drying and pulverizing the lump unmodified lignin by a known method, or a commercially available product can be used.

As a method of reacting unmodified lignin and carboxylic acid, for example, unmodified lignin, carboxylic acid and inorganic acid (for example, hydrochloric acid, sulfuric acid, etc.) are mixed and reacted.

The mixing ratio of the carboxylic acid is, for example, 300 parts by mass or more, preferably 500 parts by mass or more, for example, 15000 parts by mass or less, based on 100 parts by mass of the unmodified lignin. Preferably, it is 10000 parts by mass or less.

The blending ratio of the inorganic acid is such that the inorganic acid (100% conversion) is, for example, 0.01 parts by mass or more, preferably 0.05 parts by mass or more with respect to 100 parts by mass of the unmodified lignin. 10 parts by mass or less, preferably 5 parts by mass or less.

Such carboxylic acid-modified lignin is excellent in handleability.

That is, lignin that has not been modified with carboxylic acid has relatively low solubility in organic solvents and does not melt, so that it may be inferior in handleability depending on the application.

On the other hand, lignin modified with carboxylic acid as described above is an organic solvent (for example, esters such as methyl acetate, ethyl acetate, butyl acetate and isobutyl acetate, for example, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone). For example, aliphatic alcohols such as methanol, for example, phenols such as phenol, cresol, bisphenol A, for example, ethers such as diethyl ether, tetrahydrofuran and dioxane, such as methyl cellosolve acetate, ethyl cellosolve acetate, methylcarbyl Tall acetate, ethyl carbitol acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxybuty Glycol ether esters such as acetate and ethyl-3-ethoxypropionate, for example, nitriles such as acetonitrile, others, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, hexa Since it is relatively soluble in polar solvents such as methylphosphonilamide and can be melted at a relatively low temperature (about 100 to 200 ° C.), it is excellent in handling.

Therefore, the carboxylic acid-modified lignin can also be used as a solution of the above organic solvent. In such a case, the concentration of the carboxylic acid-modified lignin in the solution is, for example, 10% by mass or more, and preferably 30% by mass or more.

The average particle size of the carboxylic acid-modified lignin is, for example, 0.1 μm or more, preferably 5 μm or more, for example, 2 cm or less, preferably 1 cm or less.

The carboxylic acid-modified lignin is obtained as a mixture of a component (soluble component) that can be dissolved by the organic solvent (preferably ethyl acetate) and a component that cannot be dissolved by the organic solvent (insoluble component). There is a case.

In such a case, a mixture of a soluble component and an insoluble component (referred to as crude carboxylic acid-modified lignin) can be used as the carboxylic acid-modified lignin.

In addition, it is possible to separate the soluble component and the insoluble component and use only the soluble component, or it is possible to use only the insoluble component. Furthermore, the separated soluble component and insoluble component can be mixed and used.

The carboxylic acid-modified lignin is preferably a soluble component.

As a method for separating the soluble component and the insoluble component, for example, the above-described extraction method using an organic solvent is employed.

The extraction conditions are appropriately set according to the organic solvent used and the physical properties of the crude carboxylic acid-modified lignin.

Also, lignin (such as unmodified lignin and carboxylic acid-modified lignin) has an aliphatic hydroxyl group in the molecule.

An aliphatic hydroxyl group is a hydroxyl group that is not directly bonded to an aromatic ring but directly bonded to an aliphatic hydrocarbon, and is distinguished from a hydroxyl group directly bonded to an aromatic ring (aromatic hydroxyl group (phenolic hydroxyl group)).

The content of the aliphatic hydroxyl group of lignin is 0.5% by mass or more, preferably 3.0% by mass or more, and 7.0% by mass or less, preferably 5.5% by mass with respect to the total amount of lignin. % Or less.

If the content of the aliphatic hydroxyl group of lignin is below the above lower limit, the reactivity between lignin and phenols and the reactivity between lignin and aldehydes are inferior, and the productivity of the novolak-type phenol resin decreases.

Further, if the content of the aliphatic hydroxyl group of lignin exceeds the above upper limit, gelation is likely to occur during the reaction of lignin, phenols and aldehydes, so that the productivity of the novolak type phenol resin is lowered.

On the other hand, if the content of the aliphatic hydroxyl group of lignin is within the above range, the reactivity between lignin and phenols and the reactivity between lignin and aldehydes are excellent, and gelation is unlikely to occur during these reactions. The productivity of the novolac type phenol resin is improved.

In addition, the content rate of an aliphatic hydroxyl group is calculated | required based on the Example mentioned later.

The lignin containing an aliphatic hydroxyl group in the above range is preferably a carboxylic acid-modified lignin derived from a herbaceous plant, more preferably an acetic acid-modified lignin derived from a herbaceous plant.

Phenols are phenols and derivatives thereof such as phenol, and further, for example, o-cresol, p-cresol, p-ter-butylphenol, p-phenylphenol, p-cumylphenol, p-nonylphenol, Examples include 2,4- or 2,6-xylenol, m-cresol, resorcinol, 3,5-xylenol, bisphenol A, dihydroxydiphenylmethane, and the like. Further, for example, halogenated phenols substituted with halogen such as chlorine and bromine can be mentioned. These phenols can be used alone or in combination of two or more.

Phenols are preferably phenol.

Examples of aldehydes include formaldehyde, paraformaldehyde, acetaldehyde, propionaldehyde, butyraldehyde (n-butyraldehyde, isobutyraldehyde), furfural, glyoxal, benzaldehyde, trioxane, tetraoxane and the like. Moreover, a part of aldehyde may be substituted with furfuryl alcohol or the like. These aldehydes can be used alone or in combination of two or more.

Preferred examples of aldehydes include formaldehyde and paraformaldehyde.

Further, aldehydes can be used as an aqueous solution, for example. In such a case, the concentration of aldehydes is, for example, 10% by mass or more, preferably 20% by mass or more, for example, 99% by mass or less, preferably 95% by mass or less.

Also, ketones can be blended with aldehydes.

Examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, acetophenone, diphenyl ketone, and the like. These ketones can be used alone or in combination of two or more.

When the ketones are blended, the blending ratio of the ketones is, for example, 0.01 parts by mass or more, preferably 1 part by mass or more with respect to 100 parts by mass of the aldehydes based on the solid content. 200 parts by mass or less, preferably 100 parts by mass or less.

In order to react lignin (lignin having an aliphatic hydroxyl group in the molecule) with phenols and aldehydes (and ketones blended if necessary (hereinafter the same)), the above components (lignin, phenols) And aldehydes) and heat.

In this reaction, the mixing ratio of the phenols is, for example, 30 parts by mass or more, preferably 50 parts by mass or more, more preferably 100 parts by mass or more, for example, 1000 parts by mass with respect to 100 parts by mass of lignin. Hereinafter, it is preferably 500 parts by mass or less, and more preferably 350 parts by mass or less.

The blending ratio of aldehydes is, for example, 5 parts by mass or more, preferably 10 parts by mass or more, for example, 35 parts by mass or less, preferably 30 parts by mass or less, relative to 100 parts by mass of phenols. is there. The blending ratio of aldehydes is, for example, 1.5 parts by mass or more, preferably 3 parts by mass or more, for example, 350 parts by mass or less, preferably 300 parts by mass or less, with respect to 100 parts by mass of lignin. It is.

If the blending ratio of each component is within the above range, various physical properties (electrical insulation, mechanical properties, heat resistance, water resistance, etc.) can be improved.

In this reaction, an acid catalyst is added. That is, each of the above components reacts under an acid catalyst.

Examples of the acid catalyst include organic acids and inorganic acids.

Examples of the organic acid include sulfonic acid compounds such as methanesulfonic acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, cumenesulfonic acid, dinonylnaphthalene monosulfonic acid, dinonylnaphthalenedisulfonic acid, for example, trimethyl phosphate, Examples thereof include phosphate esters having an alkyl group having 1 to 18 carbon atoms such as triethyl phosphate, monobutyl phosphate, dibutyl phosphate, tributyl phosphate, trioctyl phosphate, and the like, for example, formic acid, acetic acid, oxalic acid and the like.

Examples of inorganic acids include phosphoric acid, hydrochloric acid, sulfuric acid, and nitric acid.

These acid catalysts can be used alone or in combination of two or more.

The acid catalyst is preferably an organic acid, more preferably oxalic acid.

The mixing ratio of the acid catalyst is, for example, 0.1 parts by mass or more, preferably 0.3 parts by mass or more, for example, 10 parts by mass or less, preferably 100 parts by mass with respect to 100 parts by mass of phenols. 7 parts by mass or less.

The timing of addition of the acid catalyst is not particularly limited, and may be added in advance to at least one of lignin, phenols, and aldehydes, and added at the same time when lignin, phenols, and aldehydes are blended. Further, it may be added after blending lignin, phenols and aldehydes.

As reaction conditions, under atmospheric pressure, the reaction temperature is, for example, 50 ° C. or higher, preferably 80 ° C. or higher, for example, 200 ° C. or lower, preferably 180 ° C. or lower. The reaction time is, for example, 1 hour or more, preferably 2 hours or more, for example, 20 hours or less, preferably 15 hours or less.

Thereby, a novolac type phenol resin is obtained as a reaction product of lignin, phenols and aldehydes.

More specifically, a novolac-type phenol resin is obtained by the reaction of phenols and aldehydes in the presence of an acid catalyst, and the novolac-type phenol resin is modified with lignin.

That is, a novolak-type phenol resin modified with lignin (hereinafter sometimes referred to as a lignin-modified novolak-type phenol resin) is obtained.

In the reaction of lignin, phenols and aldehydes, as described above, the above components can be combined and reacted (collective reaction), but the above components are mixed and reacted (sequential reaction). ).

Specifically, in the sequential reaction, first, lignin and phenols are reacted to prepare a lignin-phenol composition containing a reaction product of lignin and phenols, and then the lignin-phenol composition and aldehyde React with a kind.

In the reaction of lignin and phenols, the phenols are blended in an excess equivalent amount with respect to lignin. Specifically, the blending ratio of phenols is, for example, 30 parts by mass or more, preferably 100 parts by mass of lignin. 50 parts by mass or more, for example, 1000 parts by mass or less, preferably 500 parts by mass or less.

In this reaction, the above acid catalyst is added.

The mixing ratio of the acid catalyst is, for example, 0.1 parts by mass or more, preferably 0.3 parts by mass or more, for example, 10 parts by mass or less, preferably 5 parts by mass with respect to 100 parts by mass of the phenols. It is as follows.

The timing of addition of the acid catalyst is not particularly limited, and may be added in advance to at least one of lignin and phenols, or may be added simultaneously with the blending of lignin and phenols. It may be added after blending lignin and phenols.

As reaction conditions, under atmospheric pressure, the reaction temperature is, for example, 60 ° C. or higher, preferably 80 ° C. or higher, for example, 250 ° C. or lower, preferably 200 ° C. or lower. The reaction time is, for example, 0.5 hours or more, preferably 1 hour or more, for example, 10 hours or less, preferably 5 hours or less.

This reaction modifies lignin with phenols. Specifically, an aliphatic hydroxyl group in the lignin molecule (in the case where the lignin is a carboxylic acid-modified lignin, an aliphatic hydroxyl group modified with a carboxylic acid and an aliphatic hydroxyl group remaining unmodified with a carboxylic acid are included. .) Is replaced by phenols.

In the above reaction, excess phenols remain as unreacted components. Therefore, the lignin-phenol composition obtained by the above reaction contains a reaction product of lignin and phenols (lignin modified with phenols) and free phenols.

Next, in this method, the lignin-phenol composition obtained as described above (that is, lignin modified with phenols and free phenols) is reacted with aldehydes.

In this reaction, the blending ratio of aldehydes is, for example, 5 parts by mass or more, preferably 10 parts by mass or more, with respect to 100 parts by mass of phenols (phenols used as a raw material in the above reaction). , 35 parts by mass or less, preferably 30 parts by mass or less.

In this reaction, the above acid catalyst can be added at an appropriate ratio, if necessary.

As a result, the above lignin-phenol composition reacts with aldehydes to obtain a novolak-type phenol resin modified with lignin (lignin-modified novolak-type phenol resin).

According to the sequential reaction as described above, it is possible to improve heat resistance, electrical insulation and water resistance.

In the production of a lignin-modified novolac type phenol resin, unreacted raw materials (unreacted phenols, etc.) and acid catalyst can be removed by a known method such as distillation, if necessary.

Such a novolak type phenolic resin (that is, lignin-modified novolak type phenolic resin) uses lignin having an aliphatic hydroxyl group in the molecule at a predetermined ratio as a raw material, so that productivity (resin yield, production rate, etc.) is improved. Excellent. In addition, a molded product excellent in various physical properties (electrical insulation, mechanical properties, heat resistance, water resistance, etc.) can be obtained.

Further, according to the above-described method for producing a novolac type phenol resin, the novolac type phenol resin can be obtained with good productivity (resin yield, production rate, etc.).

And the resin composition of this invention contains said novolak-type phenol resin as an essential component.

Moreover, the resin composition can contain a phenol resin curing agent, if necessary.

The phenol resin curing agent is not particularly limited, and a known curing agent can be used. Specifically, for example, hexamethylenetetramine, methylolmelamine, methylolurea, phenol novolac and the like can be mentioned.

These phenolic resin curing agents can be used alone or in combination of two or more.

The blending ratio of the phenol resin curing agent is appropriately set according to the purpose and application.

The resin composition can further contain an additive.

Examples of the additive include known additives added to the resin composition, known additives such as fillers (wood flour, pulp, glass fibers, etc.), colorants, plasticizers, stabilizers, release agents ( Metal soap such as zinc stearate).

These additives can be used alone or in combination of two or more. The content of the additive is appropriately set according to the purpose and application within a range that does not impair the excellent effects of the present invention.

For example, when a filler is added, the blending ratio is, for example, 10 parts by mass or more, preferably 20 parts by mass or more with respect to 100 parts by mass of the resin composition. 500 parts by mass or less, preferably 300 parts by mass or less.

The additive may be added in advance to at least one of lignin, phenols, and aldehydes, or may be added at the same time when lignin, phenols, and aldehydes are blended, and lignin, phenol It may be added after blending of aldehydes and aldehydes, or may be added directly to their reaction products.

The resin composition thus obtained contains the above-described novolak-type phenol resin (that is, lignin-modified novolak-type phenol resin), and thus has excellent productivity and various physical properties.

Therefore, such a resin composition is suitably used for the production of a molded product.

More specifically, the above resin composition is molded by a known thermosetting resin molding method such as transfer molding or compression molding. Thereby, the molded article which is excellent in various physical properties can be obtained.

Therefore, the molded product obtained can be widely used in various industrial fields such as electric parts, automobile parts, building materials, and daily necessities.

Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited to the following examples. In the following description, “part” and “%” are based on mass unless otherwise specified. In addition, specific numerical values such as a blending ratio (content ratio), physical property values, and parameters used in the following description are described in the above-mentioned “Mode for Carrying Out the Invention”, and a blending ratio corresponding to them ( Substituting the upper limit value (numerical value defined as “less than” or “less than”) or the lower limit value (number defined as “greater than” or “exceeded”) such as content ratio), physical property values, parameters be able to.

<< Content ratio of aliphatic hydroxyl group >>
The content ratio of the aliphatic hydroxyl group to the total amount of lignin was measured by the following method.

That is, first, 5 mL each of pyridine and acetic anhydride was added to 500 mg of lignin, and allowed to stand at room temperature for 24 hours to acetylate the hydroxyl group. Subsequently, pyridine and acetic anhydride were removed with an evaporator while adding toluene.

Thereafter, 5 mg of acetylated lignin was dissolved in 1 g of a solvent, and proton NMR measurement was performed under the following conditions to determine the amount of protons of the acetyl group appearing at about 1.9 ppm. On the other hand, proton NMR measurement was also performed on lignin that was not acetylated under the same conditions, and the amount of protons in the acetyl group was quantified.

Then, from the peak intensity at about 1.9 ppm of acetylated lignin, the peak intensity at about 1.9 ppm of non-acetylated lignin was subtracted to obtain the peak amount due to acetylation. This was made into the amount of aliphatic hydroxyl groups.
Apparatus: Bruker Ltd. AscendTM 400 NMR apparatus _{solvent: D 2 O37.5g + NaOD12.5g + DSS} -d 6 (3- ( trimethylsilyl) -1-propane _{-1,1,2,2,3,3-d 6} - sulfonate, sodium Standard substance) 25mg
Measurement frequency: 400MHz
Measurement temperature: 25 ° C
Number of scans: 128 times << resin yield >>
The yield of novolac type phenolic resin was calculated by the following formula.

Resin yield (%) = [mass of obtained novolac-type phenol resin] ÷ [total mass of charged raw materials] × 100
<< Manufacture of lignin >>
Production Example 1 (Lignin Acetate)
100 parts by mass of corn stover was mixed with 1000 parts by mass of 95% by mass acetic acid and 3 parts by mass of sulfuric acid, and reacted for 4 hours under reflux. After the reaction, the pulp was removed by filtration, and the pulp waste liquid was recovered. Next, after removing acetic acid in the pulp waste liquid using a rotary evaporator and concentrating until the volume becomes 1/10, 10 times the amount of the concentrated liquid (mass basis) is added and filtered, Acetic acid-modified lignin was obtained as a solid content.

The content of aliphatic hydroxyl groups in acetic acid-modified lignin was 5.1% by mass.

Production Example 2 (Alkaline Lignin)
The alkali digestion pulp waste liquid (black liquor) of the straw was neutralized and then filtered to obtain alkali lignin as a solid content.

The content of aliphatic hydroxyl group in alkali lignin was 3.1% by mass.

<Sequential reaction>
Example 1
493.5 g of phenol was put in a flask and heated to about 50 ° C. to liquefy the phenol, and then 150 g of lignin acetate obtained in Production Example 1 was added.

Next, 7.62 g of oxalic acid (acid catalyst) was added, and then reacted at 130 ° C. for 2.5 hours. This modified the acetic acid-modified lignin with phenol.

Then, it cooled to 80 degreeC, 117.4 g of paraformaldehyde was added, and it was made to react at 95 degreeC for 2.5 hours. Next, the temperature was raised to 110 ° C. at 0.5 ° C./min and reacted at 110 ° C. for 1.5 hours. Next, the temperature was raised to 120 ° C. at 0.5 ° C./min and reacted at 120 ° C. for 2 hours.

After the reaction, 2300 g of water was added, and after stirring vigorously, the mixture was allowed to stand, and water was removed by decantation to remove oxalic acid and phenol. Further, the residual phenol was removed by distillation under reduced pressure under conditions of 120 ° C. and 0.08 MPa while adding water as appropriate. The vacuum distillation was repeated until the phenol residual ratio became 1% or less.

Thereby, a novolac type phenol resin modified with acetic acid-modified lignin was obtained.

The yield of novolac type phenolic resin was 74.9%.

Moreover, 450 g of the obtained resin, 150 g of wood flour (Asahi Organic Materials Co., Ltd.) as a filler, 54 g of hexamethylenetetramine (manufactured by Lignite) as a phenol resin curing agent, and stearic acid as a mold release agent Zinc (made by Wako Pure Chemical Industries) 4.5g was mix | blended sequentially, and it knead | mixed for 10 minutes at 100 degreeC with two hot rolls, and obtained the resin composition.

Examples 2 to 4 and Comparative Example 1
A novolac type phenolic resin and a resin composition were obtained in the same manner as in Example 1 except that the formulation shown in Table 1 was used.

In Example 2, the alkaline lignin obtained in Production Example 2 was used in place of acetic acid lignin.

In Example 3, kraft lignin (manufactured by SIGMA-ALDRICH, aliphatic hydroxyl group content 4.4 mass%) was used instead of acetic acid lignin.

In Comparative Example 1, sodium lignin sulfonate (manufactured by Tokyo Chemical Industry Co., Ltd., aliphatic hydroxyl group content: 0.3% by mass) was used in place of lignin acetate.

<Batch reaction>
Example 4
493.5 g of phenol was put in a flask and heated to about 50 ° C. to liquefy the phenol, and then 150 g of acetic acid-modified lignin obtained in Production Example 1 was added.

Next, 7.62 g of oxalic acid (acid catalyst) and 117.4 g of paraformaldehyde were added and reacted at 95 ° C. for 2.5 hours. Next, the temperature was raised to 110 ° C. at 0.5 ° C./min and reacted at 110 ° C. for 1.5 hours. Next, the temperature was raised to 120 ° C. at 0.5 ° C./min and reacted at 120 ° C. for 2 hours.

The yield of novolac type phenolic resin was 69.7%.

Example 5
A novolac type phenolic resin and a resin composition were obtained in the same manner as in Example 4 except that the formulation shown in Table 2 was used.

In Example 5, alkaline lignin obtained in Production Example 2 was used in place of acetic acid lignin.

Comparative Example 2
846 g of phenol, 13.02 g of oxalic acid (acid catalyst) and 172.5 g of paraformaldehyde were placed in a flask and reacted at 95 ° C. for 2.5 hours. Next, the temperature was raised to 110 ° C. at 0.5 ° C./min and reacted at 110 ° C. for 1.5 hours. Next, the temperature was raised to 120 ° C. at 0.5 ° C./min and reacted at 120 ° C. for 2 hours.

After the reaction, 3030 g of water was added, and after stirring vigorously, the mixture was allowed to stand and water was removed by decantation to remove oxalic acid and phenol. Further, the residual phenol was removed by distillation under reduced pressure under conditions of 120 ° C. and 0.08 MPa while adding water as appropriate. The vacuum distillation was repeated until the phenol residual ratio became 1% or less.

Thereby, a novolac type phenol resin containing no lignin was obtained.

The yield of novolac type phenolic resin was 60.1%.

Moreover, 450 g of the obtained resin, 150 g of wood flour (Asahi Organic Materials Co., Ltd.) as a filler, 54 g of hexamethylenetetramine (manufactured by Lignite) as a curing agent, and zinc stearate (as a mold release agent) 4.5 g) (manufactured by Wako Pure Chemical Industries, Ltd.) were sequentially blended and kneaded with two hot rolls at 100 ° C. for 10 minutes to obtain a resin composition.

<Evaluation>
About the resin composition obtained in each Example and each comparative example, it transfer-molded for 15 minutes at 170 degreeC, and obtained the rectangular test piece for a bending test, and the disk-shaped test piece of 75 mmphi as a molded article.

Then, the obtained molded product was evaluated by the following method. The results are shown in Table 1.

(1) Glass transition temperature (Tg)
The solid dynamic viscoelasticity was measured using Rhegel-E4000 (manufactured by UBM) (frequency 1 Hz, temperature rising rate 2 ° C./min). And the peak temperature of the obtained tan-delta curve was calculated | required as glass transition temperature (Tg). The results are shown in Table 1.

(2) Bending strength The bending strength was measured at a crosshead speed of 3 mm / min and a span of 100 mm in accordance with JIS K6911 (1995 edition).

(3) Deflection temperature under load In accordance with ASTM D648 (2004 edition), using a heat distortion tester (manufactured by Mize Tester), in silicone oil, a temperature rising rate of 2 ° C./min and a load of 18.5 kg / cm ² Then, the temperature when the standard deflection amount (0.25 mm) was reached was measured.

(4) Linear expansion coefficient Using TMA / SS6000 (manufactured by Hitachi High-Tech Science Co., Ltd.), thermomechanical analysis (TMA) at a compression mode and a heating rate of 2 ° C / min under a nitrogen atmosphere, and from the slope of the obtained TMA curve, The linear expansion coefficient at 40 ° C. to 60 ° C. was determined.

(5) Volume resistivity (electrical insulation)
According to JIS K6911 (1995 edition), volume resistivity (Ω · cm) was measured using HP4339A (manufactured by Agilent Technologies).

(6) Dielectric constant Using an impedance analyzer E4991A (manufactured by Agilent Technologies), the dielectric constant at a frequency of 1 GHz was measured by the capacitance method.

(7) Water Absorption Rate After measuring the initial mass (dry mass) of the molded product and then immersing the molded product in boiling water for 2 hours, the mass (water absorption mass) and the amount of increase were measured. The rate was determined.

Water absorption (mass%)
= 100 x mass increase after immersion in boiling water / dry mass

Although the above invention has been provided as an exemplary embodiment of the present invention, this is merely an example and should not be interpreted in a limited manner. Variations of the present invention that are apparent to one of ordinary skill in the art are within the scope of the following claims.

The production method of the novolac type phenolic resin, the resin composition and the novolac type phenolic resin of the present invention can be widely used in various industrial fields such as electric parts, automobile parts, building materials and daily necessities.

Claims

Lignin having an aliphatic hydroxyl group in the molecule;
Phenols,
It is a reaction product of an aldehyde with an acid catalyst,
The novolac type phenol resin, wherein the content of the aliphatic hydroxyl group in the lignin is 0.5% by mass or more and 7.0% by mass or less based on the total amount of the lignin.
A lignin-phenol composition comprising a reaction product of the lignin and the phenols;
The novolac-type phenol resin according to claim 1, which is a reaction product with the aldehydes.
The lignin is lignin modified with acetic acid,
The novolak type phenol resin according to claim 1.
A resin composition comprising the novolak type phenol resin according to claim 1.
Including a step of reacting a lignin having an aliphatic hydroxyl group in the molecule with a phenol and an aldehyde under an acid catalyst,
The method for producing a novolac type phenolic resin, wherein a content ratio of the aliphatic hydroxyl group of the lignin is 0.5% by mass or more and 7.0% by mass or less based on a total amount of the lignin.