JP7131558B2 - Method for producing novolak-type polymer - Google Patents

Description

The present invention relates to a method for producing novolak-type polymers.

In the production of novolac type polymers, there is a risk of gelation as a problem when making them ultrahigh molecular weight. This problem is caused by the presence of unreacted aldehyde compounds, and it is necessary to adjust the charged amounts of the aromatic amine compound and the aldehyde compound to allow the charged aldehyde compounds to react completely (i.e., unreacted aldehyde compound reduction) is a common approach to control to an appropriate molecular weight, ie avoid gelation.

In order to reduce unreacted aldehyde compounds, there are known methods of sequentially adding aldehyde compounds to the reaction system or increasing the concentration of the reaction system. However, even in these methods, it is difficult to completely react the aldehyde compound, and when the concentration is increased, the viscosity of the reaction system is inevitably increased, which poses a risk of damage to the stirring blades of the reactor. In addition, there are cases where the polymer is deposited on the inner wall of the reactor due to water produced as a by-product, and adheres to the inner wall of the reactor. These are common problems in the production of novolak-type polymers.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing a novolac-type polymer that can avoid all production problems such as gelation, high viscosity, and wall-fixed matter. .

As a result of intensive studies to achieve the above object, the present inventors have found that by carrying out the polymerization reaction while removing the water produced as a by-product, no deposits are generated on the wall, and water is removed from the reaction system. By removing it, the polymerization proceeds rapidly, the reaction system can be ultra-high molecular weight even at low concentrations, and the conditions are such that unreacted aldehyde compounds that cause gelation do not remain in the reaction system and the molecular weight can be controlled to an appropriate level. and completed the present invention.

That is, the present invention provides the following method for producing a novolac-type polymer.
1. A method for producing a novolac polymer, comprising polymerizing an aromatic amine compound and an aldehyde compound in the presence of a catalyst in an organic solvent while removing water as a by-product.
2. 1. A process for making a novolak-type polymer, with azeotropic water removal.
3. 3. The method for producing a novolac polymer according to 1 or 2, wherein the organic solvent is azeotropic with water, has a lower specific gravity than water, and is immiscible with water.
4. 3. The method for producing a novolac polymer according to any one of 1 to 3, wherein the organic solvent is toluene, o-xylene, m-xylene, p-xylene, or a mixed solvent thereof.
5. 4. The method for producing a novolac polymer according to any one of 1 to 4, wherein the catalyst is an acid catalyst.
6. 5. The method for producing a novolac-type polymer, wherein the acid catalyst is sulfuric acid or sulfonic acid.
7. 6. The method for producing a novolac polymer according to any one of 1 to 6, wherein the amount of the organic solvent used is such that the mass ratio of the organic solvent to the aromatic amine compound is 1 to 50.
8. 7. The method for producing a novolac polymer according to any one of 1 to 7, wherein the aromatic amine compound is a triarylamine compound.
9. 9. The method for producing a novolac polymer according to any one of 1 to 8, wherein the aldehyde compound is an aromatic aldehyde compound.
10. 10. The method for producing a novolak-type polymer according to any one of 1 to 9, wherein the novolak-type polymer is a hyperbranched polymer.

According to the method for producing a novolak-type polymer of the present invention, it is possible to avoid all production problems such as gelation, high viscosity, and wall-fixed matter, and to produce a high-molecular-weight novolac-type polymer.

1 is a photograph of a reaction vessel after completion of the reaction (toluene solution of polymer) in Example 1. FIG. 1 is a photograph of a reaction vessel after completion of the reaction in Comparative Example 1 (when 1 equivalent or more of aldehyde was used and the reaction was performed with a dioxane solvent). 10 is a photograph of a reaction vessel in a highly viscous reaction solution (highly concentrated condition (dioxane solvent)) in Comparative Example 2. FIG.

The method for producing a novolac polymer of the present invention comprises polymerizing an aromatic amine compound and an aldehyde compound in the presence of a catalyst in an organic solvent while removing water as a by-product.

In the production method of the present invention, the aromatic amine compound is not particularly limited, and monoarylamine compounds, diarylamine compounds and triarylamine compounds can be used. Triarylamine compounds represented by formula (A) are preferred.

In formula (A), Ar ¹ to Ar ³ are each independently a divalent organic group represented by any one of formulas (A-1) to (A-5). -1) is preferred.

In formulas (A-1) to (A-5), R ¹ to R ³⁴ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. .

Here, the halogen atom includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

The alkyl group having 1 to 5 carbon atoms is preferably linear or branched, such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group and isobutyl group. , tert-butyl group, n-pentyl group and the like.

The alkoxy group having 1 to 5 carbon atoms is preferably linear or branched, and examples thereof include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy and isobutoxy. group, tert-butoxy group, n-pentyloxy group and the like.

Preferred triarylamine compounds include triphenylamine and derivatives thereof.

Although the aldehyde compound used in the present invention is not particularly limited, one represented by the following formula (B) is preferable.

In formula (B), each R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a monovalent organic represented by any of the following formulas (B-1) to (B-4) is the base.

In formulas (B-1) to (B-4), R ³⁵ to R ⁵⁸ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, a haloalkyl group having 1 to 5 carbon atoms, a phenyl a group, —OR ⁵⁹ , —COR ⁶⁰ , —NR ⁶¹ R ⁶² or —COOR ⁶³ , and R ⁵⁹ to R ⁶² are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms, or is a haloalkyl group or a phenyl group, and R ⁶³ is an alkyl group having 1 to 5 carbon atoms, a haloalkyl group having 1 to 5 carbon atoms or a phenyl group.

The haloalkyl group having 1 to 5 carbon atoms is preferably linear or branched, such as difluoromethyl group, trifluoromethyl group, bromodifluoromethyl group, 2-chloroethyl group, 2-bromoethyl group, 1, 1-difluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, 2-chloro-1,1,2-trifluoroethyl group, pentafluoroethyl group, 3-bromopropyl group, 2,2,3,3-tetrafluoropropyl group, 1,1,2,3,3,3-hexafluoropropyl group, 1,1,1,3,3,3-hexafluoro propan-2-yl group, 3-bromo-2-methylpropyl group, 4-bromobutyl group, perfluoropentyl group and the like. Examples of the halogen atom and the alkyl group having 1 to 5 carbon atoms are the same as those mentioned above.

As the aldehyde compound, an aromatic aldehyde compound is preferable. Specifically, in the aldehyde compound represented by formula (B), R is preferably a group represented by any one of formulas (B-1) to (B-4), 2- or 3- -thienyl group or a group represented by formula (B-1) is preferable, and R ³⁷ is a phenyl group among 2- or 3-thienyl groups or groups represented by formula (B-1) or a methoxy group is more preferred, and a 2- or 3-thienyl group or a group represented by formula (B-1) in which R ³⁷ is a phenyl group is even more preferred.

Preferred aldehyde compounds include benzaldehyde, 4-methylbenzaldehyde, 3-trifluoromethylbenzaldehyde, 4-trifluoromethylbenzaldehyde, 3-phenylbenzaldehyde, 4-phenylbenzaldehyde, salicylaldehyde, anisaldehyde, 4-acetoxybenzaldehyde, 4- Acetylbenzaldehyde, 2-formylbenzoic acid, 3-formylbenzoic acid, 4-formylbenzoic acid, methyl 2-formylbenzoate, methyl 3-formylbenzoate, methyl 4-formylbenzoate, 4-aminobenzaldehyde, 4-dimethyl Aromatic aldehyde compounds such as aminobenzaldehyde, 4-diphenylaminobenzaldehyde, 1-naphthaldehyde, 2-naphthaldehyde, 2-thiophenecarbaldehyde, 3-thiophenecarbaldehyde, and 9-anthracenecarbaldehyde are included.

An aromatic amine compound represented by the formula (A) and an aldehyde compound represented by the formula (B) are polymerized in the presence of an acid catalyst to obtain a repeating unit represented by the following formula (C). Novolac-type hyperbranched polymers can be synthesized.

（式中、Ａｒ¹～Ａｒ³及びＲは、前記と同じ。）

(In the formula, Ar ¹ to Ar ³ and R are the same as above.)

Preferred examples of the novolac-type hyperbranched polymer include, but are not limited to, those having a repeating unit represented by the following formula.

In the production method of the present invention, the amount of the aldehyde compound represented by formula (B) used is preferably 0.1 to 1.0 equivalents per equivalent of the aromatic amine compound represented by formula (A). 0.7 to 0.95 equivalents are more preferred.

The average molecular weight of the novolac type polymer is not particularly limited, but the weight average molecular weight (Mw) is preferably 1,000 to 2,000,000, more preferably 2,000 to 200,000. In addition, in this invention, Mw is a polystyrene equivalent measurement value by a gel permeation chromatography (GPC).

Examples of the acid catalyst include inorganic acids such as sulfuric acid, phosphoric acid and perchloric acid; sulfonic acids such as p-toluenesulfonic acid, methanesulfonic acid and camphorsulfonic acid; and organic acids such as carboxylic acids such as formic acid and oxalic acid. can be used, but sulfuric acid, sulfonic acid and the like are preferred. The amount of the acid catalyst to be used is appropriately set according to its type, but is usually preferably 0.01 to 0.5 equivalents, more preferably 0.02 to 0.2 equivalents, relative to 1 equivalent of the aromatic amine compound.

The novolac type polymer is synthesized by condensation polymerization of the aromatic amine compound and the aldehyde compound, and water is produced as a by-product due to dehydration. In the production method of the present invention, the polymerization reaction is carried out while removing this by-produced water from the reaction system.

Although the method for removing the by-product water is not particularly limited, a method of removing by azeotropy is preferable from the viewpoint of mass production. A method of removing water by azeotropy includes, for example, a method of removing by-produced water using a Dean-Stark apparatus.

At this time, it is preferable that the organic solvent is azeotropic with water, has a lower specific gravity than water, and is immiscible with water. In the present invention, "water-immiscible" refers to an organic solvent in which the amount of dissolved water is less than 5.0% by mass. Examples of such organic solvents include aromatic hydrocarbons such as toluene, o-xylene, m-xylene and p-xylene; aliphatic hydrocarbons such as heptane, hexane and cyclohexane; Ethers, 2-methyltetrahydrofuran, 4-methyltetrahydropyran, ketones such as methyl isobutyl ketone, and the like. Of these, toluene, o-xylene, m-xylene, p-xylene or mixtures thereof are preferred. The amount of the organic solvent to be used is preferably 1 to 50, more preferably 2 to 10, by mass relative to the aromatic amine compound.

The temperature during the polymerization reaction may be appropriately set depending on the raw material and solvent used, but is usually 40 to 200°C. When water is removed by azeotropy using a Dean-Stark apparatus as described above, the reaction is carried out at the reflux temperature. It is preferable to set the internal temperature higher than or equal to 10° C., and preferably 10° C. or higher than the internal temperature. Although the upper limit of the external temperature is not particularly limited, it is usually about +20°C of the internal temperature. Although the reaction time is appropriately selected depending on the reaction temperature, it is usually about 1 to 30 hours.

Hereinafter, the present invention will be described in more detail with reference to Synthesis Examples and Examples, but the present invention is not limited to these Examples. In addition, the GPC measurement was performed under the following conditions.
Apparatus: SCL-10Avp series manufactured by Shimadzu Corporation Column: Shodex KF-805 + KF-804 + KF-803
Eluent: THF
Flow rate: 1.3mL/min
Column temperature: 40°C
Detector: UV (271 nm)
Calibration curve: standard polystyrene

[Example 1]
A polymer PTPA was synthesized according to the reaction shown in the scheme below.

10 g of triphenylamine (manufactured by Zhenjiang Haitong Chemical Industry), 6.5 g (0.87 eq.) of 4-phenylbenzaldehyde (manufactured by Beijing Odyssey Chemicals), p-toluenesulfonic acid ( 0.388 g (0.05 eq.) of Kanto Kagaku Co., Ltd.) and 60 g of toluene were charged, and the temperature was raised to reflux (internal temperature: 110 to 115° C.). Maintain the external temperature at the reflux temperature (internal temperature 110-115°C) + 20°C so that the reaction system is always in a reflux state, and react for 3 hours while removing by-product water from the reaction system by azeotropy. rice field. After 3 hours, it was confirmed by GPC that the Mw of the polymer had reached around 35,000 to 45,000, and it was confirmed that all 4-phenylbenzaldehyde had disappeared and the polymerization had stopped. A toluene solution of the obtained polymer was quenched by adding 0.25 g (0.06 eq.) of triethylamine (manufactured by Tokyo Chemical Industry Co., Ltd.). The quenched polymer solution was poured into a mixed solvent of 30 g of acetone as a poor solvent and 270 g of water for precipitation. The precipitate was separated by filtration, and after repeatedly washing the filtrate with acetone, it was dried at 100° C. in a dryer to obtain the target polymer PTPA.
FIG. 1 shows a photograph of the reactor after completion of the reaction (toluene solution of polymer). Gelation of the polymer, increase in viscosity of the reaction solution, and generation of deposits on the inner wall of the reaction vessel were not observed.

[Comparative Example 1]
In a 200 mL flask connected to a Dimroth condenser, 10 g of triphenylamine (manufactured by Zhenjiang Haitong Chemical Industry), 14.9 g (2.0 eq.) of 4-phenylbenzaldehyde (manufactured by Beijing Odyssey Chemicals), p-toluenesulfonic acid ( 1.55 g (0.2 eq.) of Kanto Kagaku Co., Ltd.) and 20 g of 1,4-dioxane were charged, and the internal temperature was raised to 85°C. When the change in the Mw of the polymer over time was confirmed by GPC, it increased to Mw = 4,350 at 3.5 hours, Mw = 14,200 at 5 hours, and Mw = 48,900 at 6 hours. Gelled over time. GPC confirmed that a large amount of unreacted 4-phenylbenzaldehyde remained in the reaction solution after 6 hours.
FIG. 2 shows a photograph of the reaction vessel after completion of the reaction. Gelation occurred at the end of the reaction.

[Comparative Example 2]
In a 200 mL flask connected to a Dimroth condenser, 10 g of triphenylamine (manufactured by Zhenjiang Haitong Chemical Industry), 3.7 g (0.5 eq.) of 4-phenylbenzaldehyde (manufactured by Beijing Odyssey Chemicals), p-toluenesulfonic acid ( 1.55 g (0.2 eq.) of Kanto Kagaku Co., Ltd.) and 10 g of 1,4-dioxane were charged, and the temperature was raised to reflux (internal temperature: 100 to 106° C.). The external temperature was maintained at the reflux temperature (internal temperature 100 to 106°C) + 20°C so that the inside of the reaction system was always in a reflux state. Two hours after the start of reflux, 1.9 g (0.25 eq.) of 4-phenylbenzaldehyde and 5 g of 1,4-dioxane were successively added. 5 g of 1,4-dioxane were successively added. When the Mw of the polymer was confirmed by GPC 22 hours after the start of reflux, it was found to be 30,000 and a large amount of unreacted 4-phenylbenzaldehyde remained. In addition, since the reaction solution has a high concentration, the viscosity is increased.
FIG. 3 shows a photograph during reflux. It was observed that the reaction solution became highly viscous and swollen.

[Comparative Example 3]
In a 200 mL flask connected to a Dimroth condenser, 10 g of triphenylamine (manufactured by Zhenjiang Haitong Chemical Industry), 6.5 g (0.87 eq.) of 4-phenylbenzaldehyde (manufactured by Beijing Odyssey Chemical), p-toluenesulfonic acid ( 0.388 g (0.05 eq.) of Kanto Kagaku Co., Ltd.) and 60 g of toluene were charged, and the temperature was raised to reflux (internal temperature: 110 to 115° C.). The reaction was carried out while maintaining the external temperature at the reflux temperature (internal temperature 110 to 115° C.)+20° C. so that the inside of the reaction system was always in a reflux state. When the change in the Mw of the polymer over time was confirmed by GPC, Mw was 33,900 after 4 hours and Mw was 40,300 after 9 hours. It was suggested that Moreover, when the by-produced water returned from the Dimroth cooler into the system, violent bumping occurred on the surface of the reaction liquid, creating a very dangerous situation.

Claims (10)

A method for producing a novolac-type polymer, comprising polymerizing an aromatic amine compound and an aldehyde compound in the presence of a catalyst in an organic solvent while removing water as a by-product,
The organic solvent is azeotropic with water, has a lower specific gravity than water, and is immiscible with water, and the amount of the organic solvent used is 1 in a mass ratio with respect to the aromatic amine compound. A method for producing a novolac-type polymer in an amount of ~50 . 2. The method of claim 1, wherein water is removed azeotropically. 3. The method for producing a novolak-type polymer according to claim 2, wherein water produced by azeotropic distillation is removed using a Dean-Stark apparatus. The method for producing a novolac polymer according to any one of claims 1 to 3, wherein the organic solvent is toluene, o-xylene, m-xylene, p-xylene, or a mixed solvent thereof. The method for producing a novolac-type polymer according to any one of claims 1 to 4, wherein the catalyst is an acid catalyst. 6. The method for producing a novolac polymer according to claim 5, wherein said acid catalyst is sulfuric acid or sulfonic acid. The method for producing a novolak polymer according to any one of claims 1 to 6, wherein the amount of the aldehyde compound used is 0.1 to 1.0 equivalents per equivalent of the aromatic amine compound. The method for producing a novolak polymer according to any one of claims 1 to 7, wherein the aromatic amine compound is a triarylamine compound. The method for producing a novolac-type polymer according to any one of claims 1 to 8, wherein the aldehyde compound is an aromatic aldehyde compound. The method for producing a novolak-type polymer according to any one of claims 1 to 9, wherein the novolak-type polymer is a hyperbranched polymer.

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