JP4837908B2 - Method for producing novolac type phenolic resin - Google Patents

Description

  The present invention relates to a method for producing a novolac type phenolic resin.

  The present applicant has developed a novolak-type phenol resin in which the content and dispersion ratio of phenolic monomers and phenolic dimers are controlled by heterogeneous reaction of phenols and aldehydes in the presence of phosphoric acids. A method for producing a novolac-type phenolic resin that can be obtained in a yield is proposed (Patent Documents 1 and 2).

  In Patent Documents 1 and 2, in the system after the completion of the reaction, for example, a water-insoluble organic solvent such as methyl ethyl ketone or methyl isobutyl ketone is added and mixed to dissolve the condensate, and then left to stand to leave an organic layer and an aqueous layer After removing most of phosphoric acids by removing the aqueous layer, the phosphoric acid remaining in the organic layer is removed by washing with water.

International Publication No. 03/042267 Pamphlet International Publication No. 2004/020492 Pamphlet

  The present invention not only provides a high yield of novolak type phenolic resin in which the content and dispersion ratio of phenolic monomers and phenolic dimers are controlled, but also prevents phosphoric acid at a high recovery rate while preventing coloration. An object of the present invention is to provide a method for producing a novolac-type phenolic resin that can be recovered and has a reduced amount of washing water for the organic layer.

That is, the method for producing the novolak type phenolic resin of the present invention comprises a first step in which phenols and aldehydes are reacted in a heterogeneous system in the presence of phosphoric acids, a water-insoluble organic solvent and water after the first step. And a second step of recovering the separated aqueous layer and a cleaning step of washing the organic layer after the aqueous layer recovery with hot water or water .

  ADVANTAGE OF THE INVENTION According to this invention, the novolak-type phenol resin by which content and dispersion ratio of the phenolic monomer and phenolic dimer were controlled can be obtained with a high yield.

  In addition, by adding a water-insoluble organic solvent and water after the reaction is completed, not only the improvement of the recovery rate of phosphoric acid from the separated aqueous layer and the prevention of coloring of the recovered phosphoric acid can be achieved, but also in the separated organic layer. The amount of washing water required for removing residual phosphoric acid can be reduced.

  In the first step of the present invention, a novolac type phenol resin is obtained by subjecting phenols and aldehydes to a condensation reaction in a heterogeneous system while stirring and mixing in the presence of phosphoric acids and preferably a reaction auxiliary solvent.

  In the first step, the phenols used as a reaction raw material include, for example, phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, 2,3- Xylenol, 2,5-xylenol, 3,5-xylenol, 3,4-xylenol, 2-propylphenol, 2-isopropylphenol, 3-propylphenol, 3-isopropylphenol, 4-propylphenol, 4-isopropylphenol, 2-sec-butylphenol, 2-tert-butylphenol, 3-sec-butylphenol, 3-tert-butylphenol, 4-sec-butylphenol, 4-tert-butylphenol, 2-cyclohexylphenol, 3-cyclo Xylphenol, 4-cyclohexylphenol, 2-nonylphenol, 3-nonylphenol, 4-nonylphenol, 2-dodecylphenol, 3-dodecylphenol, 4-dodecylphenol, 2-octadecylphenol, 3-octadecylphenol, 4-octadecylphenol, Alkylphenols such as 2-isopropyl-5-methylphenol, 2-tert-butyl-4-methylphenol, 3-methyl-6-tert-butylphenol, 2,3,5-trimethylphenol, 2,3,5-triethylphenol O-isopropenyl phenol, m-isopropenyl phenol, p-isopropenyl phenol, 2-methyl-4-isopropenyl phenol, 2-ethyl-4-isopropenyl phenol Any isopropenylphenol, phenylphenol such as 2-phenylphenol, 3-phenylphenol, 4-phenylphenol, naphthylphenol such as 2-naphthylphenol, 3-naphthylphenol, 4-naphthylphenol, o-methoxyphenol , M-methoxyphenol, p-methoxyphenol, o-ethoxyphenol, m-ethoxyphenol, p-ethoxyphenol, o-propoxyphenol, m-propoxyphenol, alkoxyphenols such as p-propoxyphenol, bisphenol A, bisphenol F, bis (2-methylphenol) A, bis (2-methylphenol) F, bisphenol S, bisphenol E, bisphenol Z, 4,4′-dihydroxybiphenyl, Examples thereof include polyhydroxyphenols such as resorcinol, hydroquinone and pyrogallol, and naphthalenes such as α-naphthol, β-naphthol and dihydroxynaphthalene.

  Among these, particularly in the epoxy field, 2-phenylphenol, 2-tert-butylphenol, and 2-cyclohexylphenol are preferably used.

  The phenols are not limited to the above examples, and may be used alone or in combination of two or more.

  As a method for adding phenols, a method suitable for the purpose, such as a method in which the raw materials are added together with the raw materials or a method in which the phenols are added in a divided manner as the reaction proceeds, may be employed.

  Examples of aldehydes used as reaction raw materials in the first step include formaldehyde, formalin, paraformaldehyde, trioxane, acetaldehyde, paraaldehyde, propionaldehyde, parapropionaldehyde, benzaldehyde, salicylaldehyde, and the like. In addition, they may be used alone or in combination of two or more.

  As a method for adding aldehydes, a method suitable for the purpose, such as a method in which raw materials are added together with a raw material or a method in which the aldehydes are added in a divided manner as the reaction proceeds, may be employed.

  The compounding ratio (F / P) of phenols (P) and aldehydes (F) is not particularly limited, but is preferably 0.33 to 1.0, more preferably 0.6 to 1.0 on a molar basis. 0.97. If the blending ratio is less than 0.33, it may be difficult to reduce the content of components below the phenol dimer. Conversely, if it exceeds 1.0, unreacted aldehydes increase and production efficiency decreases. there's a possibility that.

  In the first step, phosphoric acids used as a reaction catalyst play an important role in forming a phase separation reaction (heterogeneous reaction) between phenols and aldehydes. Examples include, for example, polyphosphoric acid such as metaphosphoric acid, pyrophosphoric acid, orthophosphoric acid, triphosphoric acid, and tetraphosphoric acid, phosphoric anhydride, and mixtures thereof. Generally 75 mass% phosphoric acid, 89 mass% phosphoric acid, etc. are used.

  The blending amount of phosphoric acids is preferably 5 parts by mass or more with respect to 100 parts by mass of phenols, and the upper limit is not particularly limited, but considering reaction volume efficiency, safety, phase separation effect, etc. Preferably it is 20-200 mass parts, More preferably, it is 40-100 mass parts. When the blending amount is less than 5 parts by mass, the production of a high molecular weight component is promoted, while the low molecular weight component, particularly the phenolic dimer component, tends not to be reduced.

  As a method for adding phosphoric acids, a method suitable for the purpose, such as a method in which the raw materials are added together with a raw material or a method in which the phosphoric acid is added in a divided manner as the reaction proceeds, may be employed.

  In the first step, it is preferable to use a non-reactive oxygen-containing organic solvent as a reaction auxiliary solvent from the viewpoint of promoting the phase separation reaction. As the reaction auxiliary solvent, it is preferable to use at least one selected from the group consisting of alcohols, polyhydric alcohol ethers, cyclic ethers, polyhydric alcohol esters, ketones, and sulfoxides.

  Examples of alcohols include monohydric alcohols such as methanol, ethanol, and propanol, butanediol, pentanediol, hexanediol, ethylene glycol, propylene glycol, trimethylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, and tripropylene glycol. And dihydric alcohols such as polyethylene glycol and trihydric alcohols such as glycerin.

  Examples of the polyhydric alcohol ether include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monopentyl ether, ethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether, ethylene glycol mono Examples include glycol ethers such as phenyl ether.

  Examples of the cyclic ethers include 1,3-dioxane and 1,4-dioxane. Examples of the polyhydric alcohol ester include glycol esters such as ethylene glycol acetate. Examples of ketones include Examples include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of the sulfoxide include dimethyl sulfoxide and diethyl sulfoxide.

  Among these, methanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol, polyethylene glycol, 1,4-dioxane and the like are particularly preferable.

  The reaction auxiliary solvent is not limited to these, and can be used as a solid as long as it has the above-mentioned characteristics and exhibits a liquid state at the time of the reaction. You may use the above together.

  Although it does not specifically limit as a compounding quantity of a reaction auxiliary solvent, Preferably it is 5-1000 mass parts with respect to 100 mass parts of phenols, More preferably, it is 10-500 mass parts. If the blending amount is less than 5 parts by mass, the effect of adding a solvent may not be recognized, and if it exceeds 1000 parts by mass, the productivity may decrease in terms of reaction rate and volumetric efficiency.

  As a method for adding the reaction auxiliary solvent, a method suitable for the purpose may be employed, such as a method in which the reaction auxiliary solvent is added together with the raw material or a method in which the reaction auxiliary solvent is added in a divided manner as the reaction proceeds.

  Further, by using a surfactant in the first step as necessary, the phase separation reaction can be promoted, the reaction time can be shortened, and the yield can be improved.

  Surfactants include soaps, alpha olefin sulfonates, alkyl benzene sulfonic acids and their salts, alkyl sulfate salts, alkyl ether sulfate salts, phenyl ether ester salts, polyoxyethylene alkyl ether sulfate salts, ether sulfonate salts. , Anionic surfactants such as ether carboxylates, polyoxyethylene alkylphenyl ethers, polyoxyalkylene alkyl ethers, polyoxyethylene styrenated phenol ethers, polyoxyethylene alkylamino ethers, polyethylene glycol aliphatic esters, aliphatic monoglycerides Sorbitan aliphatic ester, pentaerythritol aliphatic ester, polyoxyethylene polypropylene glycol, aliphatic alkylol amide, etc. Nonionic surface active agents, monoalkyl ammonium chloride, cationic surfactants such as amine acid salts.

  Although it does not specifically limit as a compounding quantity of surfactant, Preferably it is 0.5 mass part or more with respect to 100 mass parts of phenols used as a reaction raw material in a 1st process, More preferably, it is 1-10 mass. Part.

  In the first step, from the viewpoint of the phase separation effect, the water content in the system is preferably 40% by mass or less, preferably 20% by mass or less in advance before starting the reaction. From the viewpoint of reaction efficiency and phase separation effect, the reaction temperature is generally 40 ° C or higher, preferably 80 ° C or higher, and more preferably reflux temperature. The reaction time is determined in consideration of the reaction temperature, the amount of phosphoric acid, the water content of the reaction system, the condensation state of the product, etc., but is generally about 1 to 50 hours. The reaction environment is usually atmospheric pressure, but the reaction may be performed under pressure or under reduced pressure as long as the heterogeneous reaction characteristic of the present invention is maintained.

  The present invention includes a second step of adding a water-insoluble organic solvent and water after the first step and recovering the separated aqueous layer.

  Specifically, after the first step, a water-insoluble organic solvent is added and mixed while stirring and mixing to reduce the viscosity of the condensate (novolak-type phenol resin) obtained in the first step, and then water is added. Add and mix and stir and mix. Thereafter, stirring and mixing are stopped and the mixture is allowed to stand, and separated into an organic layer (including phenols and condensate) and an aqueous layer (including phosphoric acids and a reaction auxiliary solvent when added). Next, after removing the aqueous layer out of the system, the phosphoric acid and the reaction auxiliary solvent are recovered, while the organic layer is removed with a few traces of phosphoric acid by means of washing with hot water and / or neutralization several times. Alternatively, after deactivation, residual moisture and water-insoluble organic solvent are completely removed by concentration under reduced pressure.

  Examples of the water-insoluble organic solvent added in the second step include ketones, alcohols, ethers and esters.

  Examples of the ketones include methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, diisopropyl ketone, diethyl ketone, ethyl-n-butyl ketone, cyclohexanone, di-n-propyl ketone, and methyl-n-amyl ketone.

  Examples of alcohols include n-butanol, isobutanol, 2-methyl-1-butanol, and the like. Alcohols that are freely mixed with water, such as isopropanol, ethanol, and methanol, are not suitable.

  Examples of ethers include anisole, diethyl ether, dibutyl ether, dipropyl ether and the like. Ethers that are freely mixed with water, such as dioxane and dimethyl ether, are not suitable.

  Examples of the esters include ethyl acetate, isobutyl acetate, isopropyl acetate and the like.

  Among these, ketones such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, and diethyl ketone are preferable, and methyl isobutyl ketone is particularly preferable.

  The addition ratio of the water-insoluble organic solvent is not particularly limited, but is preferably 10 to 500 parts by mass, more preferably 30 to 300 parts by mass with respect to 100 parts by mass of the phenols. If the addition ratio is less than 10 parts by mass, the effect of reducing the viscosity may not be obtained, and if it exceeds 500 parts by mass, it is not preferable from the viewpoint of volume efficiency and raw material cost.

  On the other hand, the addition ratio of water is not particularly limited, but the greater the amount, the more preferable is the contrast between the organic layer and the aqueous layer when they are separated. Specifically, the amount of water in the system after the addition is 50 parts by mass or more, preferably 100 parts by mass or more, more preferably 120 parts by mass or more with respect to 100 parts by mass of the phenols used as a reaction raw material. It is preferable to add to. The greater the difference in contrast between the organic layer and the aqueous layer, the more organic components are excluded from the aqueous layer and remain on the organic layer side, and phosphoric acid is excluded from the organic layer and remain on the aqueous layer side. When the organic component dissolved in the water layer decreases, the recovered phosphoric acid is less colored, and when the phosphoric acid dissolved in the organic layer decreases, the recovery rate of the recovered phosphoric acid is improved.

  When the production method of the present invention is used, although it varies somewhat depending on the type of phenols, generally, depending on the range of the blending molar ratio (F / P) of aldehydes (F) and phenols (P), A novolac-type phenolic resin is obtained.

  When the blending molar ratio (F / P) is in the range of 0.80 mol or more, preferably 0.80 mol or more and 1.00 mol or less, the ratio between the phenolic monomer and the phenolic dimer is measured by the area method of gel filtration chromatography. The total content is 10% or less, preferably 5% or less, and the dispersion ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) by gel filtration chromatography is preferably 1.1 to A novolac-type phenol resin characterized by being 3.0, more preferably 1.2 to 2.0 can be produced in high yield.

  Further, when the blending molar ratio (F / P) is in the range of 0.33 or more and less than 0.80, the content of the phenolic monomer component is 3% or less, preferably 1%, as measured by the area method of gel filtration chromatography In the following, the content of the phenolic dimer component is 5% to 95%, preferably 10% to 90%, and the dispersion ratio between the weight average molecular weight (Mw) and the number average molecular weight (Mn) by gel filtration chromatography ( Mw / Mn) is 1.05 to 1.8, preferably 1.1 to 1.7, and a novolac type phenolic resin can be produced in a high yield.

  Examples The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. “%” Means “mass basis” unless otherwise specified. Further, the properties of the obtained novolac type phenolic resin and recovered phosphoric acid were measured by the following test method.

(1) Phosphoric acid concentration Ion chromatograph IC-2001 manufactured by Tosoh Corporation (column: SuperIC-AP, solvent: 2.9 mM NaHCO ₃ +3.1 mM Na ₂ CO ₃ , flow rate: 0.8 ml / min, column temperature: 40 ° C).

(2) Number average molecular weight (Mn), weight average molecular weight (Mw), dispersion ratio (Mw / Mn)
Number average in terms of standard polystyrene as measured by Tosoh Corporation gel filtration chromatograph SC-8020 series build-up system (column: G2000H _XL + G4000H _XL , detector: UV254 nm, carrier: tetrahydrofuran 1 ml / min, column temperature 38 ° C.) The molecular weight (Mn) and the weight average molecular weight (Mw) were determined, and the dispersion ratio (Mw / Mn) was calculated.

(3) Content of phenolic monomers and phenolic dimers (%)
The area of the phenolic monomer and phenolic dimer with respect to the total area of the molecular weight distribution was measured by an area method that displays the percentage.

(4) Softening point Based on the ring-and-ball method described in JIS-K6910, it measured using the ring-and-ball type automatic softening point measuring apparatus ASP-MGK2 made by Meitec.

(5) Hue ORBECO ANALYTICAL SYSTEMS, INC. Using the Gardner-Heligue colorimeter “No. 600-DA (Color Disc: No. 620C-44)” manufactured by Gardner, the colors of the recovered phosphoric acid and the color disc were compared, and the color number of the closest standard color Was selected and judged according to the following criteria.
A: 9 or less.
○: 10 to 18 (upper limit).
X: Darker than 18 (upper limit).

<Example 1>
(First step)
In a reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, 850 parts of phenol (P) and 510 parts of 89% by mass phosphoric acid (60% / P) were charged, and then the contents were stirred and mixed. Heated to about ℃. Next, split injection of 92.64 parts (92% by mass) of paraformaldehyde (F) (F / P = 0.85) was started, and gradually, using the heat of reaction under a cloudy state (two-phase mixture). The temperature was raised to the reflux temperature (98-110 ° C.). After 92 mass% paraformaldehyde was added in portions over 2 hours, a condensation reaction was further performed at reflux temperature for 4 hours, and then the reaction was stopped.

(Second step)
Next, 2550 parts of diisobutyl ketone as a water-insoluble organic solvent was added with stirring and mixing to reduce the viscosity of the condensate, and then 2550 parts of pure water (water content in the system after addition: 325% / P) was added. Added and stirred for 30 minutes. Thereafter, stirring and mixing were stopped and the mixture was allowed to stand, and separated into an organic layer (diisobutyl ketone and reaction condensate layer: upper layer) and an aqueous layer (phosphoric acid aqueous solution layer: lower layer). Next, 3200 parts of the aqueous layer was removed, and the organic layer was washed with water several times to remove phosphoric acid remaining in a trace amount. Table 1 shows the concentration of phosphoric acid in the organic layer after removal of the aqueous layer and the amount of washing water required for washing the organic layer. Thereafter, residual moisture and diisobutyl ketone were completely removed by concentration under reduced pressure to obtain 900 parts of a novolak resin (yield 106% / P). The yield of the novolak resin was expressed as a percentage with respect to the amount of phenol charged (mass basis).

  On the other hand, the aqueous layer removed in the second step was charged into a reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, and then water and an organic solvent contained in a trace amount were removed by vacuum concentration, and 89% Was prepared as a recovered phosphoric acid.

  The evaluation results are shown in Table 1. In addition, “ND” in the table means that it was not detected.

<Examples 2-5, Comparative Examples 1-5>
A novolak resin was produced and evaluated in the same manner as in Example 1 except that the conditions of the first step and the second step were changed as shown in Table 1. The results are shown in Table 1.

Claims (6)

A first step in which phenols and aldehydes are reacted in a heterogeneous system in the presence of phosphoric acids, and a second step in which a water-insoluble organic solvent and water are added after the first step and a separated aqueous layer is recovered. And a step of washing the organic layer after the aqueous layer recovery with hot water or washing with water .   The method for producing a novolak type phenol resin according to claim 1, wherein the water-insoluble organic solvent is methyl isobutyl ketone.   3. The method for producing a novolac type phenol resin according to claim 1, wherein in the first step, the phosphoric acid is 5 parts by mass or more with respect to 100 parts by mass of the phenols.   The said 1st process WHEREIN: The compounding quantity of aldehyde is 0.33 mol or more and 1.0 mol or less with respect to 1 mol of phenols, The novolak in any one of Claims 1-3 characterized by the above-mentioned. Type phenolic resin production method.   The method for producing a novolac type phenolic resin according to any one of claims 1 to 4, wherein in the first step, a non-reactive oxygen-containing organic solvent is present as a reaction auxiliary solvent.   6. The reaction cosolvent is at least one selected from the group consisting of alcohols, polyhydric alcohol ethers, cyclic ethers, polyhydric alcohol esters, ketones, and sulfoxides. Of producing a novolac-type phenolic resin.