JP4786832B2 - Aromatic oligomer and method for producing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the fields of paint (including water resistance imparting agents, vibration damping imparting agents, etc.), building materials field (including heat resistance imparting agents, etc.), and electrical parts field (resin modifiers, vibration damping imparting agents, etc. And an aromatic oligomer that can be used in the automotive field (including heat insulating materials, vibration damping materials, undercoat materials, etc.) and the like, and a method for producing the same.
[0002]
[Prior art]
Resins obtained by reacting phenols and formaldehydes in the presence of an acid catalyst are well known as phenol resins or novolac resins. A resin obtained by reacting an aromatic hydrocarbon such as xylene with formaldehyde in the presence of an acid catalyst is well known as a hydrocarbon resin. Further, indene-coumarone resin and petroleum resin are also known as hydrocarbon resins. In this case, since indene, coumarone, and cyclopentadiene itself have an olefin bond, formaldehyde is not used.
Japanese Examined Patent Publication No. 53-24973 describes the use of an aromatic oil resin obtained by reacting an aromatic oil and formaldehyde in the presence of an acid catalyst as a paint compounding material. JP-B-59-52887, JP-A-7-242719, and JP-A-8-157571 disclose resin compositions containing phenolic resin containing naphthalene, methylnaphthalene and acenaphthene.
[0003]
However, when making a condensation resin by reacting phenol, aromatic oil and formaldehyde in the presence of a Bronsted acid catalyst such as sulfuric acid, generally, JP-A-48-42040, JP-B-6-84414. As described in JP-A-7-242719, aromatic oil and formaldehyde are first reacted in the presence of an acid catalyst to synthesize an aromatic formaldehyde resin, and subsequently in the presence of an acid such as paratoluenesulfonic acid. It is well known to synthesize by adding phenol. However, in this method, unless the ratio (F / P) of the number of moles of formaldehyde used (F) to the number of moles of phenol (P) is less than 1, three-dimensional crosslinking occurs during the reaction, so-called gel As a result, the desired phenol-modified aromatic formaldehyde resin cannot be produced. Therefore, it is supposed that the F / P ratio is 0.3 to 0.95.
In WO01-16199, a polycyclic aromatic oligomer obtained by condensing a polycyclic aromatic compound having two or three rings, phenols, and formaldehydes in the presence of an acid catalyst is produced. How to do is described.
[0004]
[Problems to be solved by the invention]
The present invention is intended to provide a novel aromatic oligomer useful in the field of paints, electrical parts, automobiles, and the like, and a method for producing the same. Another object of the present invention is to provide a method for producing a phenol-modified polycyclic aromatic oligomer having an F / P ratio of 1 or more, which is difficult to produce by a conventional method, by a simple method.
[0005]
[Means for Solving the Problems]
The present invention relates to an aromatic oligomer obtained by condensing at least one phenol selected from the group consisting of 2 to 3 polycyclic aromatic compounds, phenol and meta-substituted alkylphenols with formaldehyde, and the aromatic oligomer When the polycyclic aromatic compound component is 1 mol, the phenol component is 0.01 to 0.35 mol, and the number average molecular weight is 300 to 1500. After reacting a polycyclic aromatic compound and c) formaldehyde in the presence of an acid catalyst, b) add phenols and a hydrocarbon solvent to the reaction mixture, and react in the presence of an acid catalyst. The method for producing an aromatic oligomer. Here, the hydrocarbon solvent is an aromatic hydrocarbon solvent. When the phenolic component in the aromatic oligomer is 1 mol, the formaldehyde content is 1 mol or more, or when the polycyclic aromatic compound component in the aromatic oligomer is 1 mol, the formaldehyde content is 0.5 It is -2.0 and it is a preferable one aspect | mode of the aromatic oligomer obtained by this invention that OH value is 5-160.
[0006]
The present invention also includes a) a polycyclic aromatic compound and c) formaldehydes reacted in the presence of an acid aqueous solution catalyst, and then adding a hydrocarbon solvent to separate an aqueous layer and an organic layer, Then, b) the method for producing an aromatic oligomer, wherein phenols are dropped and reacted in an organic layer in which at least a part of the acid catalyst and the hydrocarbon solvent remain. The amount of the hydrocarbon solvent used is as follows: the volume of the hydrocarbon solvent is V, the volume of the organic layer in the reaction mixture is A, the content of the unreacted a) polycyclic aromatic compound contained in the organic phase Is preferably in the range of 0.4 to 9, where (V + A × B / 100) / (A × (100−B) / 100). Preferred examples of the hydrocarbon solvent include aromatic hydrocarbon solvents such as benzene, alkylbenzenes, naphthalene, and alkylnaphthalenes. Moreover, as a polycyclic aromatic compound, naphthalene, methyl naphthalene, or these containing oils are mentioned preferably.
[0007]
The aromatic oligomer of this invention and its manufacturing method are demonstrated. The aromatic oligomer is generally a mixture unless a pure raw material is used. In the present specification, unless otherwise specified,% representing purity or concentration means% by weight. The component in the aromatic oligomer refers to a unit or group when a monomer such as naphthalene or phenol is present in the oligomer, but for simplicity of explanation, the unit or group present in the oligomer. May be simply referred to as naphthalene or phenols. In addition, formaldehyde has a methylene bond or dimethylene ether bond, but may be formaldehyde.
[0008]
a) The polycyclic aromatic compound is composed of bicyclic aromatic hydrocarbons such as naphthalene, methylnaphthalene, dimethylnaphthalene and biphenyl, and tricyclic aromatic hydrocarbons such as acenaphthene, fluorene, anthracene, phenanthrene and terphenyl. Examples thereof include 2- to 3-ring polycyclic aromatic compounds or 2- to 3-ring heterocyclic aromatic compounds such as benzothiophene and methylbenzothiophene, preferably naphthalene, methylnaphthalene, dimethylnaphthalene or aromatics containing these It is a mixture of oil and the like.
[0009]
When used as a reaction raw material, the polycyclic aromatic compound may be, for example, an aromatic hydrocarbon oil containing 90% or more of naphthalene or a high-purity product, but is an aromatic hydrocarbon oil mainly containing this. May be. Aromatic hydrocarbon oils include fractions corresponding to tar oil-based naphthalene oil, methylnaphthalene oil, intermediate oil, etc., and intermediate products obtained by recovering the main components from these fractions by distillation, extraction, etc. There is residual oil. These naphthalene-containing oils, methylnaphthalene-containing oils, and the like are often mixtures containing polycyclic aromatic compounds and the like that have these as the main components and approximate boiling points.
[0010]
Aromatic hydrocarbon oils containing naphthalene, as well as aromatic hydrocarbons as main components, are heteroaromatic compounds containing N, S, O, etc. as ring constituents, and constituents thereof. In addition to an aromatic compound having a functional group, it may contain a non-reactive aliphatic hydrocarbon or the like. In addition, phenols may be contained in unrefined aromatic hydrocarbon oil, but this is calculated as phenols. The aromatic hydrocarbon oil containing 90% or more of naphthalene may be purified naphthalene, but a preferred example includes 95% grade naphthalene. This can include benzothiophene, methylnaphthalene, and the like as other components.
[0011]
The c) formaldehydes used in the present invention are not limited as long as they formaldehyde itself or formaldehyde in a reaction system, and formaldehyde, formalin, paraformaldehyde and the like can be used, but paraformaldehyde is advantageous.
[0012]
B) Phenols used for obtaining aromatic oligomers can be meta-substituted alkylphenols such as metacresol, 3,5-xylenol and meta-t-butylphenol in addition to phenol. Monohydric phenols such as alkylphenols substituted with 1 to 3 lower alkyl groups of ˜4 are desirable from the standpoint of reactivity, oligomer physical properties, and the like. Phenols and meta-substituted alkylphenols give good aromatic oligomers, but tend to cause gelation during production, and the production method of the present invention can be suitably employed.
[0013]
The catalyst used in the reaction of the present invention for obtaining the aromatic oligomer is an acid catalyst, and as the acid catalyst, inorganic acids such as sulfuric acid, phosphoric acid and hydrochloric acid, organic acids such as oxalic acid and toluenesulfonic acid, silica-alumina, zeolite In addition, solid acid such as ion exchange resin and acid clay can be used, but aqueous acid catalyst such as toluenesulfonic acid and sulfuric acid is preferable. Although the usage-amount of an acid catalyst changes with kinds of acid catalyst, generally it is about 0.5 to 20 weight% of a reaction raw material as an acid.
[0014]
Formaldehydes are necessary to increase the molecular weight of aromatic oligomers and to increase the reaction rate of polycyclic aromatic compounds such as naphthalene, but if they are too much, they form gels or a large amount of terminal methylol groups remain. The risk of doing so increases. Phenols are not only effective for increasing the molecular weight of aromatic oligomers, but also have the effect of imparting moderate polarity and improving adhesiveness to metal materials. Characteristics are lost. The polycyclic aromatic compound has an effect of improving vibration damping properties, appropriately adjusting the polarity of the aromatic oligomer, and increasing compatibility with other resins such as SBR and solvents.
[0015]
In the present invention, first, a) a polycyclic aromatic compound and c) formaldehyde are reacted (first reaction) to obtain a reaction mixture, and then b) reaction with a phenol (second reaction). After completion of the first reaction, b) phenols may be added to separate the reaction product without separating the reaction product, or after the completion of the first reaction, catalyst separation or the like may be performed for polycyclic aromatic compound-formaldehyde. The oligomer intermediate may be separated, and then c) phenols may be added to this intermediate to cause a second reaction.
[0016]
The reaction conditions for the first reaction vary depending on the raw materials and catalysts used, but the reaction temperature is 50 to 180 ° C., preferably 60 ° C. to 120 ° C., the reaction time is about 0.5 to 5 hours, preferably 2 to 5 hours. Is common. The catalyst used in this reaction is an acid catalyst. Examples of the acid catalyst include inorganic acids such as sulfuric acid, phosphoric acid and hydrochloric acid, organic acids such as oxalic acid and toluenesulfonic acid, silica alumina, zeolite, ion exchange resin, acidic clay, etc. The solid acid can be used. The amount of the acid catalyst used varies depending on the type of the acid catalyst, but is generally about 0.5 to 20% by weight of the reaction raw material (in terms of acid catalyst not containing water).
[0017]
The reaction conditions for the second reaction vary depending on the raw materials and catalysts used, but the reaction temperature is generally 50 to 180 ° C. and the reaction time is generally about 0.5 to 5 hours. The catalyst used in this reaction is an acid catalyst. Examples of the acid catalyst include inorganic acids such as sulfuric acid, phosphoric acid and hydrochloric acid, organic acids such as oxalic acid and toluenesulfonic acid, silica alumina, zeolite, ion exchange resin, acidic clay, etc. The solid acid can be used. The amount of the acid catalyst used varies depending on the type of the acid catalyst, but is generally about 100 wtppm to 10 wt% of the reaction raw material (in terms of an acid catalyst not containing water). In the second reaction, phenols having higher reactivity than the polycyclic aromatic compound are reacted, and therefore the amount of catalyst used may be less than that in the first reaction. For example, if a 60% sulfuric acid aqueous solution is used as a catalyst for the first reaction, and then the sulfuric acid aqueous solution is separated by layer separation, about 500-2000 ppm of sulfuric acid remains in the organic layer together with saturated water, so a new catalyst is obtained. The second reaction can proceed without adding.
[0018]
By the way, if the sulfuric acid aqueous solution is separated by layer separation, in some cases, trace amounts of formaldehyde present in the aqueous layer (catalyst layer) can be removed simultaneously, and formaldehyde and phenols react to form a phenol resin. It is also possible to solve the problem that a gelation product is formed due to the reaction of the first reaction product, the reaction of the first reaction product, the unreacted polycyclic aromatic compound, and the reaction of formaldehyde with phenol. If the method of separating the aqueous catalyst solution by layer separation in this way is employed, not only the addition of a new catalyst becomes unnecessary, but also an undesirable reaction such as a gelation reaction can be prevented. When the amount of the catalyst is insufficient, it can be newly added, or the degree of layer separation can be slightly incomplete.
[0019]
In the second reaction, a hydrocarbon solvent such as toluene is present. b) Phenols are advantageously reacted by dropping. The hydrocarbon-based solvent is also effective for separating the aqueous solution layer and the organic layer after the completion of the first reaction. Therefore, when performing the layer separation, it is advantageous to add it before the layer separation. Preferable examples of the hydrocarbon solvent include aromatic hydrocarbon solvents such as benzene, alkylbenzenes, naphthalene, and alkylnaphthalenes. If the polycyclic aromatic compound that is liquid in the reaction system used as the raw material for the first reaction can be used as the aromatic hydrocarbon solvent, the unreacted polycyclic aromatic compound and the aromatic hydrocarbon solvent can be separated. In addition to simplifying the separation process, the recycling rate of the polycyclic aromatic compound and the aromatic hydrocarbon solvent can be improved. Since there is a difference in the reactivity of b) phenols and a) polycyclic aromatic compounds, b) phenol can be obtained if the conditions of the second reaction are mild (catalyst concentration, raw material concentration, temperature, etc.). It is possible to selectively react only the kind.
[0020]
As the hydrocarbon solvent, a) a polycyclic aromatic compound can be used as long as it shows a liquid state in the reaction system (including a case where it is dissolved in another reaction raw material to show a liquid state). In this case, the second reaction has milder reaction conditions (lower catalyst concentration, lower reaction temperature, etc.) than the first reaction, and a) the polycyclic aromatic compound acts as a solvent and does not substantially become a reaction raw material. It is desirable to use reaction conditions. A solvent such as toluene is excellent in action as a solvent, but industrially requires a recovery facility and tanks, which is disadvantageous in terms of facility, and therefore one is selected depending on conditions.
[0021]
The smaller the amount of the hydrocarbon solvent used, the more economical it is, but the more economical, the more the reaction and separation are better for the sake of stable reaction and easier layer separation. It will be a thing. The amount of the organic layer in the first reaction mixture is generally about 5 to 50 vol%, preferably about 10 to 20 vol%, but this increases or decreases depending on the content of unreacted a) polycyclic aromatic compound. Therefore, when the volume of the hydrocarbon solvent is V, the volume of the organic layer in the reaction mixture is A, and the content of the unreacted a) polycyclic aromatic compound contained in the organic phase is Bwt%, V + A × B / 100) / (A × (100−B) / 100) is in the range of 0.4 to 9, preferably about 0.5 to 7. From another point of view, a) the polycyclic aromatic compound is in the range of 5 to 200 wt%, preferably in the range of 10 to 100 wt%.
[0022]
The proportions of a) polycyclic aromatic compounds, b) phenols, and c) formaldehyde used as reaction raw materials vary depending on the target polycyclic aromatic oligomer, and there are no particular restrictions, but the following proportions It is desirable that The molar ratio of formaldehydes is calculated in terms of formaldehyde. c) Formaldehydes / a) Polycyclic aromatic compounds (molar ratio) are 0.5 to 1.0, preferably 0.6 to 0.9, and b) phenols / c) formaldehydes (P / F weight ratio) is 0.01 to 0.5, preferably 0.02 to 0.1.
The abundance of each component in the aromatic oligomer varies depending on the reactivity and reaction conditions of each raw material component, but in the case of the above raw material usage ratio, c) formaldehyde content / b) phenols (molar ratio) Is 1 or more, preferably 10-20. Further, c) formaldehydes / a) polycyclic aromatic compounds (molar ratio) are 0.5 to 2.0, preferably 0.6 to 0.9, and b) phenols / a) polycyclic aromatics. The group compound (molar ratio) is 0.01 to 0.35, preferably 0.02 to 0.1.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
An example of the preferable manufacturing method of this invention is demonstrated. In the first reaction, a polycyclic aromatic compound and formaldehyde are reacted with an aqueous sulfuric acid catalyst to synthesize a polycyclic aromatic-formaldehyde intermediate. Next, an organic solvent is added to facilitate separation of the sulfuric acid catalyst and to control the second reaction with phenols. Then, after standing still and separating the sulfuric acid aqueous solution catalyst (a small amount of sulfuric acid catalyst remains in the remaining water), stirring is started, and an amount of phenol or meta-substituted alkylphenol with an F / P ratio in the range of 1 or more is dropped. Then, the second reaction is performed. In the second reaction, a reaction in which a methylol group contained in the polycyclic aromatic-formaldehyde intermediate produced in the first reaction and phenols react mainly occurs.
[0024]
After completion of the reaction, this is subjected to distillation. First, low-boiling substances such as water and formaldehyde are distilled off, and then the pressure is reduced to 200 to 300 ° C. to distill off unreacted raw materials and other distillates. Let The residue is an aromatic oligomer. In addition, after completion | finish of reaction, you may perform a catalyst removal process by water washing etc. as needed. In this case, progress of reaction stops here, and when not performing, reaction progresses partially during distillation.
When an excessive amount of naphthalene-containing oil is used as the aromatic compound, purified naphthalene can be obtained by crystallization or washing from a naphthalene fraction recovered as an unreacted raw material.
[0025]
The aromatic oligomer thus obtained has a number average molecular weight in the range of 300 to 1,000, a weight average molecular weight in the range of 500 to 2000, and a ratio in the range of 1.5 to 3. Moreover, this aromatic oligomer has a softening point of 50 to 180 ° C.
[0026]
【Example】
Examples of the present invention will be described below. In the examples,% is% by weight and parts are parts by weight.
Example 1
250 parts of coal-based crude naphthalene (naphthalene content 96%) and 50 parts of 88% paraformaldehyde were charged into a flask and a condenser was attached. While maintaining this at 100 ° C., 60 parts of 60% sulfuric acid was added dropwise, and the mixture was stirred and reacted at 120 ° C. for 3 hours to produce an oligomer.
After completion of the reaction, transfer to a separatory funnel, add 50 parts of toluene, and allow to stand at 80 ° C. for 1 hour. The separated lower aqueous layer was separated, and 325 parts of an organic layer (having a naphthalene content of 33%, and about 500 to 2000 ppm of sulfuric acid catalyst remaining together with water remaining in the organic layer) was again charged to the flask, and a condenser was attached. . While stirring, the temperature was kept at 120 ° C. and 45 parts of phenol was slowly added dropwise. After completion of the dropping, stirring was continued for 30 minutes. The generated water was refluxed internally.
Thereafter, 100 parts of water was added to the system, sodium bicarbonate was added little by little, and when neutralization was confirmed, stirring was stopped, and the contents were transferred to a separatory funnel and allowed to stand at 80 ° C. for 1 hour. Thereafter, the lower aqueous layer was removed.
[0027]
Subsequently, the flask was transferred to a flask, and distillation was started at normal pressure. By 200 ° C., low-boiling substances such as water, formaldehyde and toluene were distilled. Distillation was carried out at a reduced pressure of 50 mmHg from 200 ° C., the temperature was raised to 270 ° C., and unreacted raw materials were distilled off. The resin remaining in the flask was 260 parts of a transparent brown phenol-modified aromatic oligomer having a softening point of 95 ° C. As a result of measuring the molecular weight by gel permeation chromatography in terms of polystyrene, it was an oligomer having a number average molecular weight of 600, a weight average molecular weight of 1500, and a distribution (dispersion index) of 2.5.
[0028]
Comparative Example 1
250 parts of coal-based crude naphthalene (naphthalene content 96%) and 50 parts of 88% paraformaldehyde were charged into a flask and a condenser was attached. While maintaining this at 100 ° C., 60 parts of 60% sulfuric acid was added dropwise, and the mixture was stirred and reacted at 120 ° C. for 3 hours to produce an oligomer.
After completion of the reaction, the mixture is transferred to a separatory funnel and left at 80 ° C. for 2 hours without adding toluene. The separated lower aqueous layer was separated, and 275 parts of an organic layer (having a naphthalene content of 39% and a sulfuric acid catalyst of about 500 to 2000 ppm remaining together with moisture) was charged again into the flask, and a condenser was attached. While stirring, the temperature was kept at 120 ° C., 45 parts of phenol was added and stirring was continued for 30 minutes. The generated water was refluxed internally. The reaction proceeded rapidly, and black suspended matter was generated in the system at the stage of 30 minutes of reaction, and the viscosity of the reaction solution also increased rapidly. When the reaction was stopped and the internal liquid was confirmed, it was confirmed that a gelled product was generated.
[0029]
Example 2
250 parts of coal-based crude naphthalene (naphthalene content 96%) and 60 parts of 88% paraformaldehyde were charged into a flask and a condenser was attached. While maintaining this at 100 ° C., 60 parts of 60% sulfuric acid was added dropwise, and the mixture was stirred and reacted at 120 ° C. for 3 hours to produce an oligomer.
After completion of the reaction, transfer to a separatory funnel, add 50 parts of toluene, and allow to stand at 80 ° C. for 1 hour. The separated lower aqueous layer was separated, and 335 parts of an organic layer (having a naphthalene content of 25% and a sulfuric acid catalyst of about 500 to 2000 ppm remaining together with moisture) was again charged into the flask, and a condenser was attached. While stirring, the temperature was kept at 120 ° C., and 45 parts of mixed cresol (m-cresol: 60%, p-cresol: 30%) was slowly added dropwise. After completion of the dropping, stirring was continued for 30 minutes. The generated water was refluxed internally.
Thereafter, 100 parts of water was added to the system, sodium bicarbonate was added little by little, and when neutralization was confirmed, stirring was stopped, and the contents were transferred to a separatory funnel and allowed to stand at 80 ° C. for 1 hour. Thereafter, the lower aqueous layer was removed.
Subsequently, the flask was transferred to a flask, and distillation was started at normal pressure. By 200 ° C., low-boiling substances such as water, formaldehyde and toluene were distilled. Distillation was carried out at a reduced pressure of 50 mmHg from 200 ° C., the temperature was raised to 270 ° C., and unreacted raw materials were distilled off. The resin content remaining in the flask was 240 parts of a transparent brown phenol-modified aromatic oligomer having a softening point of 95 ° C. As a result of measuring the molecular weight by gel permeation chromatography in terms of polystyrene, it was an oligomer having a number average molecular weight of 550, a weight average molecular weight of 1400, and a distribution of 2.5.
[0030]
【The invention's effect】
According to the production method of the present invention, a phenol-modified polycyclic aromatic oligomer having an F / P ratio of 1 or more, which is difficult to produce by conventional methods, can be produced by a simple method.

Claims (6)

An aromatic oligomer obtained by condensing at least one phenol selected from the group consisting of 2 to 3 ring polycyclic aromatic compounds and phenol and meta-substituted alkylphenols with formaldehyde, the polycycle in the aromatic oligomer In the case of producing an aromatic oligomer having a phenol compound content of 0.01 to 0.35 mol and a number average molecular weight of 300 to 1500, assuming that the aromatic compound content is 1 mol, a) a polycyclic aromatic compound The compound and c) formaldehyde are reacted in the presence of an acid catalyst, and then b) phenols and an aromatic hydrocarbon solvent are added to the reaction mixture and reacted in the presence of an acid catalyst. A method for producing an aromatic oligomer.   The method for producing a polycyclic aromatic oligomer according to claim 1, wherein when the phenol content in the aromatic oligomer is 1 mol, the formaldehyde content is 1 mol or more.   The aromatic according to claim 1 or 2, wherein when the polycyclic aromatic compound content in the aromatic oligomer is 1 mol, the formaldehyde content is 0.5 to 2.0 mol and the OH value is 5 to 160. Production method of oligomer. The aromatic hydrocarbon solvent according to any one of claims 1 to 3, wherein the aromatic hydrocarbon solvent is at least one aromatic hydrocarbon solvent selected from the group consisting of benzene, alkylbenzenes, naphthalene and alkylnaphthalenes. Production method of oligomer. After reacting a) a polycyclic aromatic compound and c) formaldehyde in the presence of an acid catalyst comprising an acid aqueous catalyst, an aromatic hydrocarbon solvent is added to separate the aqueous solution layer and the organic layer, Then, b) phenol is dripped and made to react with the organic layer in which the said acid catalyst and aromatic hydrocarbon-type solvent at least partially remain | survive, The manufacturing method of the aromatic oligomer in any one of Claims 1-4. The use amount (volume) V of the aromatic hydrocarbon solvent is such that the volume of the organic layer in the reaction mixture is A, and the content of the unreacted a) polycyclic aromatic compound contained in the organic phase is Bwt%. The aromatic oligomer according to claim 1, wherein (V + A × B / 100) / (A × (100−B) / 100) is in the range of 0.4 to 9. Method.