JP2609536B2 - Polyphenylene ether copolymer composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel polyphenylene ether copolymer composition. More specifically, the repeating unit (b) substituted with a dialkylamino group is 1/10 of the main repeating unit (a).
The present invention relates to a polyphenylene ether copolymer composition characterized by containing at least 00.

[Conventional technology]

Polyphenylene ether is a resin having excellent heat resistance and mechanical properties, and is widely used as a molding material. In order to industrially produce this polyphenylene ether, a method is generally employed in which a substituted phenol is subjected to oxidative coupling polymerization in the presence of a catalyst. In general, a side reaction such as oxidation occurs, which includes a heterogeneous structure.
Thus, there is a problem that the heterogeneous structure has an undesirable effect on the polymer. For this reason, many proposals have been made to solve the problem, and one of them is to improve the properties of polyphenylene ether by using, for example, an aliphatic secondary amine as one component of a polymerization catalyst. (See JP-A-52-897).

[Problems to be solved by the invention]

In the above-mentioned JP-A method, the polyphenylene ether contains a structure formed by bonding an aliphatic secondary amine to the benzyl position at the ortho position of the terminal hydroxyl group of the polymer (the structure (C) described later). Although it has the effect of improving the color tone and improving the color tone, the aliphatic secondary amine bond structure is thermally decomposed at the time of melt molding, and low molecular weight amines and derivatives thereof are formed. As a result of remaining in the molded article, a new problem of unpleasant odor at the time of molding has arisen. This is a problem that is particularly important in application fields where odor is important, such as food containers for microwave ovens, and application fields in which hot water extract is a problem, and improvement has been desired.

[Means for solving the problem]

The present inventors have conducted studies to solve the above-mentioned problems. As a result, in the case of the structure of the general formula (b) in which the bond position of the aliphatic secondary amine is a benzyl position other than the terminal, almost no bond is formed during melt molding. It has been found that it does not decompose and therefore has no problem such as odor, and that the color tone is equal to or more than that of the structure in which a secondary amine is bonded to the terminal benzyl position (the (C) structure described later). Reached.

That is, the present invention relates to a compound represented by the general formula (a) defined in the claims and a repeating unit represented by the general formula (b), wherein the molar ratio of (a) to (b) is 50 (a). / 1000
≧ (b) ≧ (a) / 1000, wherein (b) is present at a position other than the polymer terminal, and the number average degree of polymerization is from 50 to 1,000. The present invention provides a polymer composition.

In the above, the unit (a) or (b) should be bonded to the O atom side of (b), and it is better not to directly bond the H atom.

In the polyphenylene ether copolymer composition of the present invention, it is necessary that the repeating unit represented by the general formula (b) be contained at least 0.1 per 100 main repeating units (a). Although there is no particular upper limit, the number is preferably 5 or less per 100 pieces of (a). In addition to this, it does not prevent coexistence of a heterogeneous structure of the same degree as that present in a polymer obtained by a known technique for producing polyphenylene ether, but it is preferable to keep it as small as possible.

In particular, the following terminal structure (c) having an aliphatic secondary amine bonded thereto should be suppressed to a small amount.

This is because the structure (c) is considered to release the amine by heating during molding or the like by the reaction shown in the following formula.

The amine causes an unpleasant odor, becomes an extractable component with a solvent or hot water, and causes coloring.

The main repeating unit in the polyphenylene ether copolymer composition mixture of the present invention is represented by the general formula (a), and any phenylene ether group known to copolymerize with this is represented by (a) May be contained by 1/2 or less.

The degree of polymerization is preferably in the range of 50 to 1000 in number average, and is expressed in number average molecular weight in the case of R ₁ = CH ₃ from about 6,000 to 120,000. In particular, those having a number-average degree of polymerization of 100 to 300 are preferred for use as an engineering resin.

In addition, the number average polymerization degree of the present invention is, as specifically shown in the section of [Examples] described later, the number average molecular weight in terms of polystyrene obtained by gel permeation chromatography and the formula weight of the main repeating unit (a). (For example, when R ₁ = CH ₃ , 12
0.2).

The repeating unit (a) preferably has a methyl group at the 2- and / or 6-position. Representative examples of monomers corresponding to these include o-cresol, 2,6-dimethylphenol, 2,3,6-trimethylphenol, 2-methyl 6-phenylphenol, and the like in the present invention. Does not prevent coexistence of these or some of them with 2,6-diphenylphenol or the like. Of these, 2,6-dimethylphenol is particularly preferred.

The secondary aliphatic amine corresponding to the di-substituted amino group in the repeating unit (b) is represented by the formula (d) HNR ₂ R ₃ ... (d) wherein R ₂ and R ₃ are each independently or both And cyclic organic groups]. Preferred secondary aliphatic amines are those in which R ₂ and R ₃ each have 1 to 20 carbon atoms.
And more preferably 1 to 10 amines. Secondary aliphatic amines wherein R ₂ and R ₃ are each C _1-8 , preferably C _2-6 , more preferably C _3-5 alkyl groups, especially in that they are readily commercially available at present. Is preferred.

 Specific examples of secondary amines are shown below.

Dimethylamine, diethylamine, di-n-propylamine, di-secondary propylamine, di-n-butylamine, di-secondary-butylamine, di-tertiary-butylamine, dipentylamines, dihexylamines, Diheptylamines, dioctylamines, dinonylamines, didecylamines, dieicosylamines, dibenzylamines, methylethylamine, methylbutylamines, methylcyclohexylamine, heptylcyclohexylamine, octadecylcyclohexylamine and the like.

In the terminal structure (c), even if a substituent having some function is selected for R ₂ and R ₃ , it is almost ineffective because it decomposes and separates from the polymer during heat molding. Because it does not decompose when heated,
It has been found that various functions can be provided. For example, a functional group with good adhesion to the filler or a group compatible with other resins
By incorporating into R ₂ and R ₃ , an excellent composition can be developed. Dialkanolamines and the like are particularly preferred examples of secondary amines for this purpose.

The method for producing the polyphenylene ether copolymer of the present invention is not particularly limited. For example, a method substantially similar to the known oxidative coupling polymerization of phenols in the presence of a secondary aliphatic amine represented by the general formula (f) is used. It can be manufactured using. That is, a solution containing a phenol represented by the general formula (e) and a secondary aliphatic amine represented by the general formula (f):
The polymerization is carried out by adding a catalyst and, if necessary, a cocatalyst, and supplying an oxygen-containing gas with vigorous stirring.

In this production method, first, a structure (c) in which a secondary amine is bonded to a terminal group is formed at an early stage of polymerization, and then a polymer chain grows from the terminal hydroxyl group to become a repeating unit (b).

When the conventional polymerization method is applied as it is, the terminal group (d)
Since the polymerization reactivity of is significantly lower than the polymerization reactivity of a normal non-aminated terminal group, most of the terminal group remains as a repeating unit (b), and the repeating unit (b) is compared with the main repeating unit (a). Could not generate more than 1/1000. As a result of the present inventors' earnestly searching for a method for efficiently reacting the terminal group bonded to the secondary amine, the following three methods were found to be effective. One is to raise the polymerization temperature as high as possible. In particular, it is to raise the polymerization temperature in the middle stage of the reaction when the terminal structure (c) is almost completely formed and the polymerization reaction is actively proceeding. One is to increase the monomer concentration at the later stage of the reaction (about 80% to 95% in conversion of hydroxyl group). Another is to use a highly active catalyst. Particularly, catalysts having high activity at high temperatures are limited. The catalyst used in the method for producing polyphenylene ether shown in JP-A-1-33131 is one example of this. Incidentally, increasing the amount of the secondary amine used was not so effective. The post-treatment method after the completion of the reaction is not particularly limited. Normally, a catalyst such as hydrochloric acid or acetic acid is added to a reaction solution to deactivate the catalyst, the resulting polymer is separated, washed with a solvent that does not dissolve the polymer such as methanol, and then dried. By operation, polyphenylene ether can be recovered.

The polyphenylene ether copolymer obtained by this method has a remarkably large amount of the repeating unit (b) as compared with that obtained by polymerization in the presence of a conventional aliphatic secondary amine. Is sufficiently satisfied. Although the number of secondary amine-bonded terminals (c) is considerably smaller than that of a conventional polymer, it may be necessary to further reduce the number depending on the application. There are two effective means in such a case. One is to remove portions of relatively low molecular weight in the polymer mixture. After the terminal structure (c) occurs in the early stage of polymerization,
Because the polymer did not grow on the hydroxyl side,
Naturally, it is abundant in the low molecular weight region. This tendency is particularly remarkable when polymerizing while precipitating the polymer. Typically, if a low molecular weight region of about 5% by weight is removed by dissolution and reprecipitation, the terminal group (c) is removed by about 30 to 40%, and the repeating unit (b) is removed by only 5 to 10%. Absent. If it is necessary to completely remove the terminal group (c), a second method is to decompose by heating in advance. Specifically, a method for removing amines released by decompression while melting or after melting, a method for removing amines released by fusion and cooling and then extraction, a polymer solution or a slurry in which some polymer is precipitated After heating in the state described above, there is a method of precipitating the polymer and separating it from the released amine.

〔The invention's effect〕

The polyphenylene ether copolymer composition of the present invention,
Compared with the conventional polyphenylene ether, the color and viscosity increase at the time of heat molding are greatly improved, and the excellent properties of having an excellent property that an unpleasant odor at the time of molding and use can be suppressed without impairing other properties. It is a united composition.

〔Example〕

Hereinafter, the present invention will be described specifically with reference to Examples.
The present invention is not limited by these examples.
In addition, each measurement was performed on condition of the following.

The viscosity of the polymer was measured with a 0.5% chloroform solution at 30 ° C. using an Ubbelohde viscosity tube. Expressed as ηsp / c.

The molded product was prepared by mixing the powders obtained in Examples and Comparative Examples with 310.
Refers to a test piece molded under heat and pressure at 180 kg / cm ² for 10 minutes.

Δη / η is a value obtained by dividing the difference between ηsp / c of the powder and the molded product by ηsp / c of the powder, and is used as an index of the viscosity increase during heat molding.

The coloring degree was determined by dissolving 0.5 g of the molded product in chloroform to make a total amount of 10 ml, measuring the absorbance at 480 nm at 25 ° C., and evaluating the color index (coloring index) defined by the following formula.

Where l ₀ : intensity of incident light l: intensity of transmitted light a: cell length [cm] b: solution concentration [g / cm ³ ] The total nitrogen bond amount of polyphenylene ether is JIS K
It was measured according to the micro Kjeldahl method of 2609.

¹ H-nuclear porcelain resonance spectrum was measured by GX manufactured by JEOL Ltd.
The measurement was performed at -270 using CDCl ₃ as a solvent.

Gel permeation chromatography (GP
C) was measured with HL-802RTS manufactured by Toyo Soda Kogyo Co., Ltd., and calibrated with standard polystyrene.

Example 1 Polymerization was carried out using a continuous polymerization reactor comprising three complete mixing tanks. The first reactor has a capacity of 1.5 and is equipped with a circulation pump. The second reactor and the third reactor have a stirrer with capacities of 3.7 and 1.5, respectively.

The catalyst solution was prepared by dissolving cuprous oxide in 35% hydrochloric acid, adding methanol, and further adding di-n-butylamine, N, N, N ', N'-tetramethyl-1,3-diaminopropane and methanol. . The monomer solution was prepared by dissolving 2,6-dimethylphenol in mixed xylene and n-butanol. Each was prepared under air.

The catalyst solution and the monomer solution were sent to the first reactor and methanol was sent to the second reactor at a constant rate.

Based on the amounts of the catalyst solution and the monomer solution sent, the composition of the reaction raw material solution combining them is as follows.

The weight ratio of the solvent used for the 2,6-dimethylphenol concentration of 20% by weight was mixed xylene: n-butanol: methanol = 6.
0:20:20. However, half of the methanol was sent to the second reactor.

Per 100 mol of 2,6-dimethylphenol, 0.06 g atom of copper, 0.55 g atom of Cl ion, 1.5 mol of di-n-butylamine, 1.5 mol of N, N, N ', N'-tetramethyl-1,3-diamino Propane was 3 moles. Also, 2,6-dimethylphenol was supplied at a rate of 160 g / Hr.

In the first reactor, oxygen was flowed while vigorously circulating the reaction solution with a circulation pump. The internal temperature was controlled to be 40 ° C. The reaction solution sent from the first reactor to the second reactor at the head pressure was uniform.

While stirring vigorously in the second reactor, oxygen gas was
The temperature was kept at 35 ° C. at a rate of one minute. The polymer precipitates, but is uniformly distributed throughout the reactor by stirring. Overflow from the second reactor, the reaction solution containing the polymer particles enters the third reactor.

While controlling the third reactor at 25 ° C., oxygen gas was flowed at a rate of 200 ml / min while stirring with a stirrer.

The reaction solution containing the polymer was continuously taken out of the third reactor by overflow.

The methanol was added to the yellowish-white reaction solution containing the slurry, followed by filtration. The mixture was sufficiently purified and washed using a mixed solvent (mixed xylene, butanol, and methanol) and dilute hydrochloric acid.
The viscosity (ηsp / c) of the polymer obtained after drying was in the range of 0.66 ± 0.03, and stable operation was possible for a long time.

Table 1 shows the results of the structural analysis and physical property evaluation of the obtained copolymer.

Comparative Example 1 In Example 1, the amounts of copper and hydrochloric acid were changed to 0.05 gram atom and 0.46 gram atom, di-n-butylamine was not added, and the feeding amount of 2,6-dimethylphenol was 172 g /
Except having changed to Hr, it carried out similarly to Example 1 and obtained the result of Table-1.

Comparative Example 2 For comparison, the following procedure was performed using a catalyst having a low polymerization activity. That is, in Example 1, copper was changed to 0.09 gram atom, hydrochloric acid was changed to 0.83 gram atom of hydrobromic acid, and
N, N, N ', N'-tetramethyldiaminopropane was changed to 1.8 mol of butyldimethylamine, and 0.18 mol of N, N'-di-tert-butylethylenediamine was further added. Also, 2,6
-The same operation was performed except that the amount of dimethylphenol fed was changed to 240 g / Hr and the temperature of the second reactor was changed to 25 ° C, and the results in Table 1 were obtained.

<< Confirmation of Polymer Structure >> The structures of the copolymers of Examples 1 and 2 and Comparative Examples 1 and 2 were determined mainly by elemental nitrogen analysis and nuclear magnetic resonance spectrum.

The terminal group (C) to which the secondary aliphatic amine is bonded is ¹ H and
Confirmed and quantified by ¹³ C nuclear magnetic resonance spectrum. That is, on the ¹ H nuclear magnetic resonance spectrum of Example 1, the signal of the methylene group of the formula (C) was observed at 3.63 ppm, and the n-butyl group —CH ₂ —CH ₂ corresponding to R ₄ and R _5. four of the ¹ H of -CH ₂ -CH ₃
The signals corresponding to the nuclei are 2.47, 1.50, 1.29, and 0.88 pp
m, and the area intensity ratio was consistent with the structure of the formula (C). The structure of the formula (C) was quantified based on the area intensity, and the polymer of Example 1 was treated with the polymer of Example 1.
Confirmed to be 20%. These signals were also observed on the spectrum of the copolymer of Comparative Example 2, and were determined to be 0.30% of (a), but were not observed at all on the spectrum of the copolymer of Comparative Example 1. In addition, on the ¹³ C-nuclear magnetic resonance spectra of the copolymers of Example 1 and Comparative Example 2, the signals of the four types of ¹³ C-nuclei of the n-butyl groups of R ₄ and R ₅ were between ^{13 and} 53 ppm. Was observed.

The structure (b) in which the aliphatic secondary amine is bonded to the benzyl position in the main chain gives a ¹ H nuclear magnetic resonance spectrum very similar to the structure of the formula (c), but the chemical shift value of each signal is represented by the formula ( It can be clearly distinguished from that of c), where the signal of the methylene group is observed at 3.36 ppm, and the two signals at the terminal of the n-butyl group are observed at 1.17 ppm and 0.80 ppm. This structure
Although 0.13% of (a) was present in the polymer of Example 1, it was not present in the polymer of Comparative Example 1 at all, and 0.02% or less of (a) was present in the polymer of Comparative Example 2. Were present.

The difference in the bonding position between the two types of secondary aliphatic amine bonding structures was clarified as follows. When the low molecular weight of about 5% was removed from the polymer of Example 1 by reprecipitation and recovery from a toluene solution with methanol, the signal assigned to the formula (c) decreased from 0.20 mol% to 0.11 mol%. On the other hand, the signal assigned to the formula (b) hardly decreased. In the low molecular weight region of 5%, the signal assigned to (c) was unevenly distributed at 1.7 mol%, but the signal assigned to formula (b) was hardly concentrated. The ubiquitous distribution in the low molecular weight region is a typical feature of the terminal group, and the structure of Formula (b) and Formula (c) was determined by this.

The presence of the main repeating unit (a) was confirmed by ¹ H-the magnetic resonance spectrum and the like.

Example 2 In Example 1, the amounts of copper, hydrochloric acid, and N, N, N ', N'-tetramethyl-1,3-diaminopropane were changed to 0.05 gram atom, 0.46 gram atom and 2.5 mole, Performed in the same manner as in Example 1, except that the feed amount of 6,6-dimethylphenol was changed to 172 g / Hr, the temperature of the second reactor was changed to 45 ° C, and the temperature of the third reactor was changed to 40 ° C. A copolymer was obtained. The viscosity of the obtained copolymer was η = 0.57. In this copolymer, (b) is 0.18 per 100 main repeating units (a).
The presence of 0.30 of (c) was confirmed by ¹ H-nuclear magnetic resonance spectrum. This copolymer was molded under pressure and heat at 250 ° C. for 20 minutes and analyzed again.
Although there was almost no decrease to 0.16 per 100 pieces (c)
Was not observed at all. Instead, N, N-dibutylamine and the like were observed, but these could be almost completely removed by the operation of dissolution and reprecipitation. After all, as the N-containing structure (b)
A copolymer containing only the above was obtained.

Claims (1)

(57) [Claims] (1) A repeating unit represented by the following general formula (a) and a repeating unit represented by the following general formula (b) have a molar ratio of (a) to (b) of 50 (a) / 1000 ≧ (b ) ≧ (a) / 1000
A polyphenylene ether copolymer composition, wherein (b) is present at a position other than the terminal of the polymer, and the number average degree of polymerization is from 50 to 1,000. (Wherein, R ₁ represents hydrogen, an alkyl group or an aryl group having 1 to 4 carbon atoms, and R ₂ and R ₃ represent the same or different alkyl groups having 1 to 20 carbon atoms and substituted alkyl groups)