JP2008101038A - Method for producing novolak type phenol resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method by which a novolak type phenol resin wherein not only the contents of monomer and dimer components of phenols, but also the contents of trimer and tetramer components of the phenols are little can be produced in good efficiency. <P>SOLUTION: The method for producing the novolak type phenol resin includes a step for heterogeneously reacting phenols with 0.90-2.0 mol aldehydes based on 1 mol phenols in the presence of phosphoric acids and/or an organic phosphonic acid, and alcohols and/or cyclic ethers. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

  A novolac type phenol resin is generally produced by reacting phenols and aldehydes to a desired degree of condensation in the presence of an acid catalyst to synthesize an initial condensate, and then concentrating at high temperature under reduced pressure. The novolak-type phenolic resin obtained by such a production method contains a large amount of phenolic monomers and dimer components with odor and irritation, but environmental pollution due to such aeration is a problem. Methods for reducing the phenolic monomer and dimer components have been investigated.

  For example, a method for removing not only phenolic monomers but also dimer components by blowing an inert gas or water vapor when concentrating the novolak condensate after the condensation reaction at 150 to 210 ° C. has been proposed (Patent Document 1). ). However, according to this method, although the effect of reducing low molecular weight components such as phenolic monomers or dimers is certain, a large amount of medium molecular weight components exceeding the trimers that could not be removed remain, while high molecular weight components are converted into resins. As a result, the molecular weight distribution becomes wider, and the yield of the resin is reduced due to the removal of low molecular weight components.

  As another method for reducing the low molecular weight component in the novolak type phenol resin, there is a fractionation method represented by a liquid / liquid separation method (Patent Document 2). However, if these fractionation methods are used for conventional novolak type phenol resins containing a large amount of low molecular weight components, the separation conditions must be strict to remove a large amount of phenolic dimer components. In addition, the necessary high molecular weight components are also removed, and the yield is greatly reduced.

  In addition, when using a novolac type phenolic resin as a flame retardant resin, a balance of processing fluidity, mechanical properties, low smoke generation, low volatility, etc. is required, and not only phenolic monomers and dimer components, but also phenols Reduction of trimer and tetramer components is also strongly desired.

Japanese Patent Publication No. 7-91352 Japanese Patent Laid-Open No. 2-60915

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a production method capable of efficiently producing a novolak-type phenol resin that contains not only phenolic monomers and dimer components but also phenolic trimer components. And

  As a result of intensive studies to overcome the above-mentioned problems, the present inventors have further conducted a heterogeneous condensation reaction between phenols and aldehydes in the presence of phosphoric acids and / or organic phosphonic acids. It has been found that not only phenolic monomers and dimer components but also phenolic trimer components can be significantly reduced by using alcohols and / or cyclic ethers and reacting phenols and aldehydes at a specific mixing ratio. The present invention has been completed.

  That is, the method for producing the novolak type phenolic resin of the present invention comprises 0.90 to 2.0 moles of aldehydes per mole of phenols and phenols, phosphoric acids and / or organic phosphonic acids, and alcohols. And / or a heterogeneous reaction in the presence of cyclic ethers.

  According to the present invention, it is possible to efficiently produce a novolak type phenol resin in which the total content of phenolic monomers and phenolic dimers is 3% or less and the content of phenolic trimers is 5% or less. Moreover, the novolak-type phenol resin manufactured by this invention can be used suitably especially as a resin for flame retardants.

  The method for producing the novolak type phenolic resin of the present invention is formed from phenols and aldehydes as reaction raw materials, phosphoric acids and / or organic phosphonic acids as reaction catalysts, and alcohols and / or cyclic ethers. As a two-phase separation state, for example, mechanical stirring, stirring and mixing with ultrasonic waves, etc., as a cloudy heterogeneous reaction system (so-called phase separation reaction) in which two phases (organic phase and aqueous phase) are mixed, It has the adjustment process of the condensate (resin) which advances the condensation reaction of phenols and aldehydes, It is characterized by the above-mentioned.

  Examples of the phenols used as a reaction raw material include phenols, alkylphenols having 1 to 4 alkyl groups having 1 to 10 carbon atoms as substituents, such as cresol, xylenol, ethylphenol, propylphenol, butylphenol, hydroquinone, Polyphenols such as resorcin, catechol, bisphenols such as bisphenol A, bisphenol F, bisphenol S, trisphenols such as 2,4-bis (4-hydroxybenzyl) -6-methylphenol, α-naphthol, β And naphthols such as naphthol. Among these, those having no alkyl group such as phenol, hydroquinone, resorcin, catechol, α-naphthol and β naphthol are preferable, and phenol is more preferable from the viewpoint of flame retardancy and cost. The phenols are not limited to the above examples, and may be used alone or in combination of two or more.

  Examples of aldehydes used as other reaction raw materials include aliphatic aldehydes such as formalin (formaldehyde aqueous solution), paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, butyraldehyde, glyoxal, malondialdehyde, succindialdehyde, and glutardialdehyde. , Aromatic aldehydes such as benzaldehyde, salicylaldehyde, naphthaldehyde and terephthalaldehyde. Among these, formalin and paraformaldehyde are preferable, but paraformaldehyde is particularly optimal in consideration of handleability and ease of adjustment of water content. Aldehydes are not limited to the above examples, and 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 the aldehydes are added together with phenols or a method in which a part (or all) of the aldehydes is added in a divided manner as the reaction proceeds, may be employed.

  The blending amount of the aldehydes is 0.90 to 2.0 mol, preferably 0.92 to 1.5 mol, more preferably 0.95 to 1.2 mol with respect to 1 mol of phenol. In order to make the content of the phenolic tetramer component 5% or less, it is more preferably 0.96 to 2.0 mol. If the blending ratio is less than 0.90 mol, it is particularly difficult to reduce the phenol trimer component. On the other hand, if it exceeds 2.0 mol, production efficiency decreases due to removal of unreacted aldehydes and deterioration in reaction volume efficiency. Accompany.

  In addition, phosphoric acids, organic phosphonic acids and mixtures thereof used as reaction catalysts play an important role in forming a phase separation reaction field between phenols and aldehydes. Advantageous phosphoric acid is preferably used. Examples of such phosphoric acids include polyphosphoric acids such as metaphosphoric acid, pyrophosphoric acid, orthophosphoric acid, triphosphoric acid, and tetraphosphoric acid, phosphoric anhydride, and mixtures thereof. An easy orthophosphoric acid aqueous solution such as 75% by mass phosphoric acid, 89% by mass phosphoric acid, etc. is generally used.

  The organic phosphonic acid is an organic compound containing a phosphonic acid group, and preferred specific examples include, for example, ethylenediaminetetrakismethylenephosphonic acid, ethylenediaminebismethylenephosphonic acid, aminotrismethylenephosphonic acid, β-aminoethylphosphonic acid N , N-diacetic acid, aminomethylphosphonic acid N, N-diacetic acid, 1-hydroxyethylidene-1,1′-diphosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, and the like. It is not limited. Among these, 1-hydroxyethylidene-1,1'-diphosphonic acid and 2-phosphonobutane-1,2,4-tricarboxylic acid which are easily available are preferable.

  The blending amount of phosphoric acids and / or organic phosphonic acids is preferably 20 parts by mass or more, more preferably 50 parts by mass or more, and still more preferably 60 parts by mass or more with respect to 100 parts by mass of phenols. Moreover, the upper limit amount is not particularly limited, but is preferably 200 parts by mass or less, more preferably 150 parts by mass or less in consideration of reaction volume efficiency, safety, phase separation effect, and the like. If the blending amount is less than 20 parts by mass, the phenol trimer may not be reduced. As a method for adding phosphoric acids and / or organic phosphonic acid, a method suitable for the purpose, such as a method in which the raw materials are added together with the reaction raw material or a method in which the phosphoric acid and / or organic phosphonic acid are dividedly added as the reaction proceeds, may be employed.

  Alcohols and / or cyclic ethers play an important role in promoting phase separation reactions and reducing phenol trimers.

  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. Among these, a monohydric alcohol is preferable from the viewpoint of a phenol trimer reduction effect, and methanol is more preferable.

  Examples of cyclic ethers include 1,3-dioxane, 1,4-dioxane and the like. Among these, 1,4-dioxane is preferable from the viewpoint of the effect of reducing phenol trimers.

  The alcohols and cyclic ethers are not limited to the above examples, and both or each of them may be used alone or in combination.

  It is preferable that the compounding quantity of alcohol and / or cyclic ether is 10-200 mass parts with respect to 100 mass parts of phenols, More preferably, it is 20-150 mass parts, More preferably, it is 40-100 mass parts. is there. When the blending amount is less than 10 parts by mass, the phenol trimer component may not be reduced, and when it exceeds 200 parts by mass, there is a possibility that productivity decreases due to a decrease in reaction volume efficiency. As a method for adding alcohols and / or cyclic ethers, a method suitable for the purpose, such as a method in which the reaction raw materials and phosphoric acids are added together, a method in which the alcohols and / or cyclic ethers are added in a divided manner as the reaction proceeds, etc.

  In the above phase separation reaction, the amount of water in the reaction system is preferably 100 parts by mass or less, more preferably 75 parts by mass or less, more preferably 100 parts by mass or less, with respect to 100 parts by mass of phenols, from the viewpoint of the effect of reducing phenol trimers. Is 40 parts by mass or less. The moisture in the reaction system here means water blended in the reaction system directly or in a state where aldehydes are dissolved in a target amount of water in advance. In addition, there is no particular limitation on the method of blending water, depending on the purpose, such as a method of batch charging together with the raw materials as described above, a method of dividing a predetermined amount during the reaction, or a method of blending all of them. May be adopted.

  From the viewpoint of reaction efficiency and phase separation effect, the reaction temperature is generally 50 ° C. or higher, preferably 70 ° C. or higher, and more preferably reflux temperature. The reaction time is determined in consideration of the reaction temperature, the amount of phosphoric acid and / or organic phosphonic acid, the water content of the reaction system, the condensation state of the product, etc., but is generally about 1 to 50 hours. .

  It is preferable to have a washing step after completion of the reaction. Specifically, it is preferable to wash with water or hot water after the reaction, but in some cases, a water-insoluble organic solvent (for example, methyl ethyl ketone, methyl isobutyl ketone, etc.) is added and mixed to form a condensate (novolak type phenol resin). After dissolution, leave it to separate into an organic layer and an aqueous layer. Next, the aqueous layer is removed from the system, and then phosphoric acids and non-reactive oxygen-containing organic solvent are recovered. On the other hand, the organic layer is washed with hot water and / or neutralized and then water-insoluble organic by vacuum distillation. Remove the solvent.

  The novolak type phenolic resin obtained in the present invention has a total content of phenolic monomers and phenolic dimers of 3% or less, preferably 2% or less, more preferably 1% or less, and a content of phenolic trimers. It is 5% or less, preferably 3% or less, and can be suitably used particularly as a flame retardant resin. Also, considering the balance of processing fluidity, mechanical properties, low smoke generation, low volatility, etc. when used as a flame retardant resin, the total content of phenolic monomer, dimer, trimer and tetramer is 10% or less Preferably, it is 8% or less, more preferably 5% or less.

  The polystyrene-converted weight average molecular weight of the novolak-type phenolic resin obtained in the present invention is not particularly limited, but considering the balance between improvement in mechanical properties and processability when used as a flame retardant resin, 1,000 to 100,000 are preferably used, more preferably 2,000 to 50,000, still more preferably 5,000 to 50,000, and particularly preferably 5,000 to 30,000.

  In addition, the polystyrene-equivalent number average molecular weight is not particularly limited, but those having a molecular weight of 500 to 50,000 are preferably used. Processing fluidity when used as a flame retardant resin, dripping prevention effect during combustion, low smoke generation In view of the properties, low volatility, etc., the number average molecular weight is preferably 600 to 20,000, more preferably 800 to 10,000.

  EXAMPLES Next, although an Example demonstrates this invention still in detail, this invention is not limited at all by these examples. In the examples, “parts” and “%” indicate “parts by mass” and “% by mass” unless otherwise specified.

  The obtained novolac type phenolic resin was measured by the following test method.

(1) Molecular weight Gel filtration chromatograph SC-8020 series build-up system manufactured by Tosoh Corporation (column: G2000Hxl + G4000Hxl, detector: UV254 nm, carrier: tetrahydrofuran 1 ml / min, column temperature: 38 ° C.) weight average in terms of standard polystyrene by measurement Molecular weight (Mw) and number average molecular weight (Mn) were determined.

(2) Content of phenolic monomer, phenolic dimer, phenolic trimer and phenolic tetramer (%)
The area of the phenolic monomer, phenolic dimer, phenolic trimer, and phenolic tetramer relative to the total area of the molecular weight distribution was measured by an area method that displays the percentage.

<Example 1>
In a reaction vessel equipped with a thermometer, a stirrer, and a condenser, 100 parts of phenol (P), 32.9 parts of 92% by mass paraformaldehyde (F) (F / P = 0.95), 89% by mass phosphorus After charging 100 parts (100% / P) of acid and 40.0 parts (40% / P) of methanol, the mixture was gradually refluxed under a cloudy state (two-phase mixture) formed by stirring and mixing. The reaction was stopped after a condensation reaction was carried out at the same temperature for 8 hours.

  Next, after adding methyl isobutyl ketone with stirring and mixing to dissolve the condensate, stirring and mixing are stopped, and the contents are transferred into a separating flask and allowed to stand, and the methyl isobutyl ketone solution layer (upper layer) and phosphorus are mixed. Separated into an acid aqueous solution layer (lower layer). Next, after removing the phosphoric acid aqueous solution layer and washing the methyl isobutyl ketone solution with water several times to remove phosphoric acid, the contents are returned again into the reaction vessel, and methyl isobutyl ketone is completely removed by vacuum distillation to remove the novolak. Type phenolic resin was obtained.

  About the obtained novolak-type phenol resin, the characteristic was measured by the test method described at the beginning. The results are shown in Table 1. In addition, “ND” in the table means that it was not detected. Moreover, the GPC chart of the obtained novolak-type phenol resin is shown in FIG.

<Examples 2-6, Comparative Examples 1-4>
A novolac type phenol resin was obtained in the same manner as in Example 1 except that the reaction conditions were changed as shown in Table 1. The measurement results are shown in Table 1. Moreover, the GPC chart of the obtained novolak type phenol resin is shown in FIGS. 2 to 6 and FIGS.

<Example 7>
A novolak-type phenol resin was obtained in the same manner as in Example 1 except that the condensation reaction was changed for 18 hours and the reaction conditions were changed as shown in Table 1. The measurement results are shown in Table 1. Moreover, the GPC chart figure of the obtained novolak-type phenol resin is shown in FIG.

<Comparative Example 5>
A reaction vessel equipped with a thermometer, a stirrer, and a condenser was charged with 100 parts of phenol, 32.9 parts of 92 mass% paraformaldehyde (F / P = 0.95) and 0.50 parts of oxalic acid, and gradually refluxed. After heating up to temperature (98-102 degreeC), the condensation reaction was performed at the same temperature for 6 hours. When dehydrated while gradually raising the temperature to 140 ° C., gelation occurred.

1 is a GPC chart of a novolac type phenol resin obtained in Example 1. FIG. FIG. 3 is a GPC chart of the novolac type phenol resin obtained in Example 2. FIG. 4 is a GPC chart of the novolak type phenol resin obtained in Example 3. FIG. 4 is a GPC chart of the novolac type phenol resin obtained in Example 4. 6 is a GPC chart of a novolac type phenol resin obtained in Example 5. FIG. 6 is a GPC chart of a novolac type phenol resin obtained in Example 6. FIG. 6 is a GPC chart of the novolac type phenol resin obtained in Example 7. FIG. 2 is a GPC chart of a novolac type phenol resin obtained in Comparative Example 1. FIG. 6 is a GPC chart of a novolac type phenol resin obtained in Comparative Example 2. FIG. 6 is a GPC chart of a novolac type phenol resin obtained in Comparative Example 3. FIG. 6 is a GPC chart of a novolac type phenol resin obtained in Comparative Example 4. FIG.

Claims (6)

  Heterogeneous system in the presence of 0.90 to 2.0 moles of aldehydes per mole of phenols and phosphoric acids and / or organic phosphonic acids and alcohols and / or cyclic ethers A method for producing a novolac-type phenolic resin, comprising a step of reacting.   The said phosphoric acid and / or organic phosphonic acid are 20 mass parts or more with respect to 100 mass parts of phenols, The manufacturing method of the novolak-type phenol resin of Claim 1 characterized by the above-mentioned.   The said alcohols and / or cyclic ether are 10-200 mass parts with respect to 100 mass parts of phenols, The manufacturing method of the novolak-type phenol resin of Claim 1 or 2 characterized by the above-mentioned.   The said alcohol is methanol, The manufacturing method of the novolak-type phenol resin in any one of Claims 1-3 characterized by the above-mentioned.   The said cyclic ether is 1, 4- dioxane, The manufacturing method of the novolak-type phenol resin in any one of Claims 1-3 characterized by the above-mentioned.   The said aldehyde is 0.96-2.0 mol with respect to 1 mol of phenols, The manufacturing method of the novolak-type phenol resin in any one of Claims 1-5 characterized by the above-mentioned.

Images