JP2003313290A - Process for depositing low-molecular weight polyphenylene ether - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deposition process for obtaining a polyphenylene ether having a broad molecular-weight distribution in an improved yield. <P>SOLUTION: In the deposition process, upon mixing a poor solvent for the polyphenylene ether and a solution into which the polyphenylene ether of a specific viscosity is dissolved, the solution temperature inside a deposition vessel is controlled to from -80 to 20&deg;C. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for precipitating polyphenylene ether particles by mixing a polyphenylene ether solution and a poor solvent for polyphenylene ether, and the polyphenylene ether particles are separated from the polyphenylene ether particles in the solvent without being precipitated and are not recovered. The present invention relates to a precipitation method for obtaining a polyphenylene ether resin having a higher yield, a lower average molecular weight, and a wider molecular weight distribution by reducing the molecular weight of polyphenylene ether.

[0002]

2. Description of the Related Art Polyphenylene ether resins made from polyphenylene ether can be used to produce products and parts of desired shapes by molding methods such as melt injection molding and melt extrusion molding. It is a widely used material for products and parts in various industrial material fields. Particularly, reduced viscosity 0.05 g /
The polyphenylene ether resin having excellent fluidity of dl to 0.30 g / dl is a material that can be suitably used as an electronic substrate material, a sealant, and the like.

As a method for producing polyphenylene ether, there is a method of oxidatively polymerizing phenols in the presence of a copper compound and amines in a good solvent for polyphenylene ether. As a method for recovering the polyphenylene ether from the polyphenylene ether solution by this method, in a solution in a room temperature or a heated state, a poor solvent for the polyphenylene ether such as methanol, which is also room temperature or heated, is added to form the polyphenylene ether particles. Methods of precipitation are known.

However, when the above-mentioned polyphenylene ether resin having a low reduced viscosity is recovered from the polyphenylene ether solvent by the conventional technique, a low molecular weight of about 10-mer is not deposited and remains on the filtrate side. However, there are problems that the yield of the recovered polymer is deteriorated, the molecular weight distribution of the recovered polyphenylene ether resin is shifted to the high molecular weight side, and various physical properties are changed due to the sharpening of the molecular weight distribution.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a method for depositing a polyphenylene ether resin by mixing a polyphenylene ether solution and a poor solvent for the polyphenylene ether, in which a low molecular weight filtrate of about 10-mer is added to the filtrate side. Remaining is reduced, the polymer yield is improved, and the molecular weight distribution of the polyphenylene ether resin in the polyphenylene ether solution is suppressed from shifting to a high molecular weight, and the molecular weight distribution of the polyphenylene ether resin in the polyphenylene ether solution state shifts to the polymer side. It is an object of the present invention to provide a method for precipitating polyphenylene ether having a broader molecular weight distribution.

[0006]

Means for Solving the Problems The present invention has been studied in order to achieve the above object, and as a result, as a result, a polyphenylene ether solution consisting of polyphenylene ether and a good solvent thereof and a poor solvent for polyphenylene ether were mixed to obtain polyphenylene ether. In the method of precipitating resin, ~ 10
Reduction of the residual amount of low molecular weight filtrate on the side of the filtrate and recovery of the low molecular weight polyphenylene ether resin more efficiently improves the polymer yield and improves the molecular weight distribution of the polyphenylene ether resin in the polyphenylene ether solution. , A method for precipitating polyphenylene ether having a broader molecular weight distribution while suppressing the shift to higher molecular weight was completed.

That is, in the present invention, the reduced viscosity measured at 30 ° C. using a chloroform solution is from 0.05 g / dl to
In a method of depositing a polyphenylene ether resin by mixing a polyphenylene ether solution having a concentration of 25% by weight to 70% by weight of a polyphenylene ether of 0.30 g / dl and a good solvent thereof and a poor solvent of polyphenylene ether A method for depositing polyphenylene ether, which comprises using a bath and controlling the liquid temperature in the depositing bath to a temperature in the range of -80 to 20 ° C.

The polyphenylene ether of the present invention has the following main chain structure (formula 1).

[0009]

[Chemical 1]

R1 and R4 in the polyphenylene ether represented by the above formula (1) of the present invention each independently represent hydrogen, primary or secondary lower alkyl, phenyl or aminoalkyl hydrocarbon oxy. . R2
R3's each independently represent hydrogen, primary or secondary lower alkyl, or phenyl.

The polyphenylene ether of the present invention has a reduced viscosity of 0.05 to 1.0 dl / g, preferably 0.05 to 1.0, measured at 30 ° C. using a chloroform solution.
It is a polymer or copolymer in the range of 0.30 g / dl. The polyphenylene ether of the present invention includes poly (2,6-dimethyl-1,4 phenylene ether), poly (2-methyl-6-ethyl-1,4-phenylene ether) and poly (2-methyl-6-phenyl). -1,4-phenylene ether, poly (2,6-dichloro-1,4-
Phenylene ether) and the like. Another specific example of the polyphenylene ether of the present invention is a copolymer of 2,6-dimethylphenol and other phenols (for example, 2,3,6-trimethylphenol or 2-methyl-6-butylphenol). Such polyphenylene ether copolymers are also included.

Among the above polyphenylene ethers of the present invention, poly (2,6-dimethyl-1,4-phenylene ether), 2,6-dimethylphenol and 2,3,6-
A copolymer with trimethylphenol can be preferably used, most preferably poly (2,6-dimethyl-1,4).
-Phenylene ether). The method for polymerizing the polyphenylene ether used in the present invention is not particularly limited.
As an example of the method for polymerizing the polyphenylene ether used in the present invention, a cuprous salt-amine complex described in US Pat. No. 3,306,874 is used as a catalyst,
There is a method of oxidatively polymerizing 2,6-xylenol. U.S. Pat. Nos. 3,306,875, 3,257,357 and 3,257,358, Japanese Patent Publication No. 52-1788.
No. 0 and JP-A Nos. 50-51197 and 63-1.
The method described in each publication of No. 52628 is also preferable as a method for producing polyphenylene ether.

The terminal structure of the polyphenylene ether of the present invention is preferably the structure of the following (formula 2).

[0014]

[Chemical 2]

[0015] wherein, _{R 1, R 2, R 3} , R 4 are defined as in _{R 1, R 2, R 3} , R 4 in the respective (Equation 1). ]

The terminal structure of the polyphenylene ether of the present invention is more preferably the structure of the following (formula 3).

[0017]

[Chemical 3]

[0018] wherein, R _1, said R ₁ in (Equation 1)
And R ₅ and R ₅ 'represent an alkyl group. ]

The good solvent for the polyphenylene ether of the present invention means a solvent in which the polyphenylene ether is satisfactorily dissolved to form a uniform polyphenylene ether solution. The polyphenylene ether solution of the present invention is a solution in which polyphenylene ether is uniformly dissolved in the solvent.

In the polyphenylene ether precipitation method of the present invention, the polyphenylene ether concentration is from 25% by weight to 70% by weight.
% By weight, and the liquid temperature in the precipitation tank is -80 ° C to 2
It is desirable to control the temperature in the range of 0 ℃, -50 ℃ ～
It is more desirable to control the temperature in the range of 10 ° C. In the polyphenylene ether precipitation method of the present invention, the weight ratio of poor solvent / good solvent in the mixed solution is preferably 1 to 12. In the polyphenylene ether precipitation method of the present invention,
The polyphenylene ether concentration in the polyphenylene ether solution is more preferably 27% by weight to 60% by weight.

As the good solvent for the polyphenylene ether of the present invention, at least one solvent selected from benzene, toluene and xylene is preferable. In the present invention,
As a good solvent for polyphenylene ether, toluene is more preferable. The polyphenylene poor solvent of the present invention is a solvent that does not dissolve polyphenylene ether. As the polyphenylene ether poor solvent of the present invention,
Methanol, ethanol, isopropanol, n-
It is preferably at least one solvent selected from butanol, acetone, methyl ethyl ketone and water.
The polyphenylene ether poor solvent of the present invention is more preferably methanol.

In the present invention, by recovering a large amount of low molecular weight components from the polymerized polyphenylene ether solution, it is possible to recover a polyphenylene ether resin closer to the molecular weight in the polyphenylene ether solution in a high yield of 90% or more. Has an aim.

In the present invention, the means for precipitating the polyphenylene ether resin from the polyphenylene ether solution using a precipitation tank was examined. As a result, the temperature in the precipitation tank, the polyphenylene ether solution, and the poor solvent for precipitation were adjusted to -80 ° C to 20 ° C. By performing the precipitation operation while controlling the temperature within the range, a much more stable precipitation operation is performed than in the past, and the residue on the filtrate side of low molecular weight of about 10-mer is reduced, and low molecular weight polyphenylene ether. Of the polyphenylene ether solution by suppressing the shift to a high molecular weight when the molecular weight distribution of the polyphenylene ether resin in the polyphenylene ether solution is recovered by more efficiently recovering the polymer in a broader polyphenylene ether solution. That polyphenylene ether resin with a molecular weight distribution close to that existing in the resin can be recovered It was.

By the precipitation method of the present invention, it is possible to recover a polyphenylene ether resin having a high yield and a molecular weight distribution close to that existing in a polyphenylene ether solution, and a method for precipitating a polyphenylene ether resin that sufficiently meets the requirements of the industrial world. Is.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to examples. However, the present invention is not limited to the following examples unless the gist thereof is changed.
The following polyphenylene ethers were used in Examples and Comparative Examples. (A) According to the method described in Example 3 of JP-B-59-23332, 30% by weight of a 2,6-dimethylphenol toluene solution in the presence of each catalyst and di-n-butylamine while bubbling oxygen. Add over 35 minutes, 74
Stop the oxygen supply after a minute. An aqueous solution of ethylenediaminetetraacetic acid trisodium salt was added to the polymerization mixture, and the mixture was mixed with 7
Keep at 0 ° C. Then, the mixture was sent to a centrifugal separator manufactured by Sharpless, and the reduction concentration of polyphenylene ether having a polyphenylene ether content of 26% was 0.11 dl / g when measured with 0.5 g / dl of chloroform. The weight average molecular weight was 5741.

[0026]

Example 1 A precipitation bath was installed in a constant temperature bath, and a 30 wt% polyphenylene solution of (A) was added in an amount as defined in Condition A of Table 1, and the temperature was adjusted to −10 ° C. while stirring with a stirrer. Maintain to be. Similarly, the amount of methanol adjusted to a temperature of 45 ° C. is added in the amount specified in Condition A of Table 1. After polymer deposition,
The mixture was filtered and vacuum dried at 140 ° C. for 1 hour. Similar operations are performed under the conditions (1) to (2) shown in Table 1. The weight ratios of methanol, which is a poor solvent, and toluene, which is a good solvent, are methanol / toluene = 5.0, 7.
The precipitation operation was performed at a ratio of 0 and 12.0. The polymer was precipitated under any of the conditions. The results are shown in Table 2. The values of weight average molecular weight are shown in Table 3.

[0027]

Example 2 The precipitation temperature was set to 1 ° C. in the same manner as in Example 1 except for the temperature. The polymer was precipitated under any of the conditions. The results are shown in Tables 2 and 3.

[0028]

[Comparative Example 1] The same procedure as in Example 1 was carried out except that the deposition temperature was 30 ° C. Under the condition that the weight ratio of methanol / toluene = 2.5, the precipitated polymer was sticky and entangled with the stirrer to form a lump. Under the condition that the weight ratio of methanol / toluene = 5.0, lumps were heavily attached to the stirring tank and the stirring bar. The results are shown in Tables 2 and 3.

[0029]

[Comparative Example 2] The same procedure as in Example 1 was carried out except that the deposition temperature was changed to 45 ° C. Under the conditions of methanol / toluene weight ratio = 2.5 and 5.0, the precipitated polymer was sticky and entangled with the stirrer to form a lump. Under the condition of the weight ratio of methanol / toluene = 7.0, the adherence of lumps to the stirring tank and the stirring bar was severe. The results are shown in Tables 2 and 3. The yield of the obtained polyphenylene ether resin was measured from the total weight. Further, for each condition, the weight average molecular weight was measured by a method using a chloroform solvent.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

[Table 3]

[0033]

The method of depositing the polyphenylene ether resin by mixing the polyphenylene ether solution and the poor solvent for the polyphenylene ether of the present invention has a high yield of 90% or more and is present in the polyphenylene ether solution. This is a method of depositing a polyphenylene ether resin which can recover a polyphenylene ether resin having a molecular weight distribution close to that of the molecular weight distribution and sufficiently meet the requirements of the industrial world.

Claims (6)

[Claims] 1. A concentration of 25% by weight to 70 consisting of polyphenylene ether having a reduced viscosity of 0.05 to 0.30 g / dl and a good solvent thereof, which is measured at 30 ° C. using a chloroform solution.
In a method of depositing a polyphenylene ether resin by mixing a polyphenylene ether solution with a weight% of polyphenylene ether and a poor solvent for polyphenylene ether, a precipitation tank is used, and the liquid temperature in the precipitation tank is controlled to a temperature in the range of −80 to 20 ° C. A method for precipitating polyphenylene ether, comprising: 2. The weight ratio of the good solvent of polyphenylene ether to the poor solvent used for precipitation is 1 to 12 in terms of poor solvent / good solvent.
The method for depositing polyphenylene ether according to claim 1, wherein 3. The method for precipitating polyphenylene ether according to claim 1 or 2, wherein the polyphenylene ether concentration in the polyphenylene ether solution is 27% by weight to 60% by weight. 4. The good solvent for polyphenylene ether is toluene, as claimed in claim 1, 2, or 3.
The method for depositing polyphenylene ether according to 1. 5. The method for precipitating polyphenylene ether according to claim 1, wherein the poor solvent used for precipitation is methanol. 6. The liquid temperature in the precipitation tank is controlled to a temperature in the range of −50 to 10 ° C., 1.
The method for depositing polyphenylene ether according to 3, 4, or 5.