JPS6347733B2 - - Google Patents

Description

[Detailed description of the invention]

Conventional polyphenylene ethers such as poly(2,6-dimethylphenylene ether) (PPO) and poly(2,6-diphenylphenylene ether) are strong, have good dimensional stability, and have excellent insulation properties. It is known as a thermoplastic resin with excellent physical properties. Furthermore, a mixture of PPO and polystyrene (commonly known as Noryl) is a plastic material with even better mechanical strength, moldability, and cost. The present invention relates to polyphenylene ethers having reactive allyl groups in their side chains. These poly(2,6-diallylphenylene ethers) can be easily derived into a series of highly useful polymeric compounds while retaining the excellent physical properties of polyphenylene ethers by utilizing the high reactivity of the allyl group in the side chain. (In this specification, the term allyl group is used to include substituted allyl groups.) One example is a graft copolymer having these poly(2,6-diallylphenylene ether) as a backbone polymer. For example, a resin made by grafting styrene onto a copolymer of 2,6-diallylphenols and 2,6-dimethylphenol has physical properties equivalent to that of Noryl, but also exhibits problems such as phase separation and migration that are observed in mixtures. It is an excellent material that overcomes the drawbacks of The present invention is based on the following new findings based on the inventors' systematic research on oxidative polymerization of phenols. A comparative study of the oxidative polymerizability of 2,6-disubstituted phenols with double bonds in their side chains revealed that monomers with double bonds conjugated to the phenol core, such as 2,6-divinylphenol, have a conjugated structure. Based on this, branching and cross-linking occur during polymerization, and linear polyphenylene ether cannot be obtained. Furthermore, in monomers in which the double bond is located far from the phenol nucleus, polymerization does not occur due to its steric bulk. Furthermore, in the case of non-2,6-disubstituted phenol, for example, in the case of 2-monosubstituted phenol, a side reaction occurs at the unprotected 6-position, and a linear polyphenylene ether cannot be obtained.
From the above results, we have reached the conclusion that 2,6-diallylphenols are the only monomers that provide polyphenylene ethers having reactive double bonds in their side chains. Homopolymers of 2,6-diallylphenols do not necessarily have high molecular weights, but by copolymerizing them with appropriate 2,6-disubstituted phenols, the molecular weight and content of reactive allyl groups can be adjusted as desired. can. Allyl groups in polyphenylene ethers are suitable for grafting by radical polymerization of vinyl monomers. The present invention was completed based on the above knowledge, and its gist is that it consists of the following repeating unit (), or it consists of a repeating unit () and a repeating unit (), and the repeating unit () is 28%
The above polyphenylene ethers have an allyl group in the side chain and have a molecular weight of 500 to 30,000. (In the formula, R ¹ and R ² represent a hydrogen atom, a lower alkyl group, or a phenyl group, and R ³ and R ⁴
represents a lower alkyl group. ) The present invention will be explained in detail below. The monomer essential to the polyphenylene ether according to the present invention has the general formula () [In the formula, R ¹ and R ² have the same meanings as in the general formula (). ] These are 2,6-diallylphenols shown as follows. R ¹ and R ² are a hydrogen atom, a lower alkyl group such as methyl, ethyl, isopropyl, or a phenyl group, and R ¹ and R ² may be the same. Representative examples of 2,6-diallylphenols are:
2,6-diallylphenol (R ¹ ==R ² =H),
2,6-diprenylphenol (R ¹ =R ² =-
CH ₃ ), 2,6-dibutenylphenol (R ¹ =
H, R ² = -CH ₃ ), 2,6-dicinnamylphenol (R ¹ = H,

[Formula]). 2,6-diallylphenols have the following reaction formula: It can be easily obtained by subjecting phenol to a heated reaction with allyl halides in the presence of an excess of sodium metal, as shown in the following formula. For example, phenol is dissolved in a nonpolar, aprotic solvent (benzene, toluene, etc., with ether being particularly good), a large excess of metallic sodium (2 to 10 times the mole) is added to the solution, and then the general formula () [In the formula, R ¹ and R ² have the same meanings as in the general formula (), and X represents a halogen atom. ] Add 2 to 5 times the mole, particularly 3 times the mole, of the allyl halide represented by the formula, and heat (usually at reflux at the boiling point of the solvent) for 10 minutes to 1 hour. In the general formula () of allyl halides,
are, for example, chlorine, bromine and iodine, of which chlorine is preferred. Examples of allyl halides include butenyl chloride, prenyl chloride, cinnamyl chloride, and the like. Next, a method for polymerizing 2,6-diallylphenols will be explained. The catalyst may be any metal complex known to be effective in the oxidative polymerization of 2,6-disubstituted phenols. That is, transition metal ions (b, b, , b, group b element ions are suitable, particularly copper ions, manganese ions, iron ions, and any form such as chloride, bromide, sulfate, etc.), It is a complex of so-called ligand compounds containing nitrogen and oxygen (especially aliphatic and aromatic amines containing basic nitrogen are good). After dissolving or suspending these catalysts in a polymerization solvent, one or more monomeric 2,6-diallylphenols are added, and the mixture is heated at 0 to 100°C, for example at room temperature, in the presence of oxygen according to a conventional method. When stirred vigorously,
Polymerization progresses easily to produce polyphenylene ether. The appropriate amount of catalyst is (monomer)/(metal component in the complex) = 1 to 1000 (molar ratio). After the polymerization is completed, the reaction solution is added dropwise to methanol acidified with hydrochloric acid according to a conventional method to obtain a polymer precipitate, which is filtered, washed, and dried to obtain poly(2,6-diallylphenylene ether). . As the polymerization solvent, methanol, ethanol, benzene, toluene, xylene, chloroform, etc. can be used, but benzenes and halogenated hydrocarbons are particularly preferred. When 2,6-diallylphenols are polymerized in this way, homopolyphenylene ether (hereinafter referred to as polymer (1)) whose repeating unit is 2,6-diallylphenylene ether represented by the general formula () is obtained. ) can be obtained. A copolymerization reaction can also be carried out in the same manner. During copolymerization,
2,6-diallylphenols and general formula () (In the formula, R ³ and R ⁴ represent lower alkyl groups.) If a mixture with one or more 2,6-disubstituted phenols represented by the formula is subjected to a copolymerization reaction in the same manner as in the above case, good. In the general formula (), R ³ and R ⁴ are lower alkyl groups such as methyl, ethyl, isopropyl, etc., and R ³ and R ⁴ may be the same. When 2,6-diallylphenols and 2,6-disubstituted phenols are copolymerized in this way,
2,6-diallylphenylene ether whose repeating unit is represented by the general formula () and general formula () (In the formula, R ³ and R ⁴ represent lower alkyl groups.) Polyphenylene ether copolymer (hereinafter sometimes referred to as polymer (2)) which is a 2,6-di-substituted phenylene ether is obtained. The molecular weight of the polyphenylene ether according to the present invention is usually 500 to 30,000. Furthermore, if the 2,6-diallylphenylene ether moiety in the polyphenylene ether is usually 28% or more, its functional groups can be effectively utilized. Next, the graft reaction will be explained. In the reaction, polymer (1) or polymer (2) as a parent polymer is dissolved in a polymerization solvent, and a vinyl monomer (styrene, vinyl acetate, vinyl pyrrolidone, methyl methacrylate, etc.) is added to this in the presence of a radical polymerization initiator according to a conventional method. This is done by adding below. In particular, in order to increase the grafting rate, it is preferable to slowly drop a small amount of the graft monomer into the solution of polymer (1) or polymer (2). (Allyl group)/(graft monomer) = 1 to 100 (mole ratio)
is appropriate. The side chain allyl groups of polymer (1) and polymer (2) can be used not only for grafting reactions but also for general induction reactions. For example, there is the following reaction. Next, examples of the present invention will be shown. Example 1 1.34 g of phenol is dissolved in 15 ml of ether, 1.32 g of metallic sodium is added to the solution in fine pieces, and the mixture is stirred at room temperature for 30 minutes. Subsequently, 4.44 g of 1-chloro-3-methyl-2-butene (prenyl chloride) was slowly added dropwise, and the mixture was refluxed for 1 hour. After the reaction, treatment was carried out in a conventional manner to obtain 3.8 g of a pale yellow oil. This was distilled under reduced pressure to obtain a fraction of 2.25 with a boiling point of 129-132℃/1.5mmHg.
g was obtained. The characteristic absorption of the infrared absorption spectrum is
3400, 1910, 1840, 1770, 1655, 1210, 830,
760, 740cm ^-1 , NMR spectrum (δ, CCl ₄ ) is
1.75 (6H, S, = C(CH ₃ ) ₂ ), 3.25 (4H, d, -
CH ₂ -), 5.00 (1H, S, -OH), 5.32 (2H, t, =
_CH2- ), 6.45 to 7.00 (3H, m) ppm, and from the above data it was confirmed that this fraction was 2,6-diprenylphenol. 80 ml of benzene, 8 ml of pyridine, 0.1 cuprous chloride
After stirring thoroughly in the presence of oxygen, 20 ml of a benzene solution containing 2.3 g of 2,6-diprenylphenol synthesized as above was added and stirred vigorously at room temperature. Polymerization started immediately and the polymerization started in 45 minutes. The reaction is complete. After the reaction was completed, the solution was washed with hydrochloric acid water,
When the solvent benzene is distilled off, a viscous oil is obtained. Yield is 87%. The infrared absorption spectrum of the produced polymer is 3400 cm ^-1 , which is characteristic of the raw material phenol.
Absorption due to ν _OH completely disappeared. Also, ν _COC can be confirmed to be the formation of polyether.
(1180cm ^-1 ) absorption became remarkable. Furthermore, based on the results of quantitative determination of double bonds using a halogen addition reaction, it was confirmed that there were two double bonds per monomer component. From these results, it was confirmed that the polymer obtained in this example was poly(2,6-diprenylphenylene ether).
The molecular weight of the benzene solution measured by the vapor pressure (VPO) method was 920. Example 2 Toluene 300ml, pyridine 30ml, cuprous chloride 200ml
After stirring thoroughly under oxygen, 4.0 g of 2,6-diprenylphenol synthesized in Example 1
(0.017mol) and 4.1g of 2,6-dimethylphenol
(0.034 mol) in toluene solution was added at room temperature and stirred vigorously. Polymerization was completed in 40 minutes, and the reaction solution was concentrated to 1/2 and then added to 2 portions of hydrochloric acid and methanol to obtain a white polymer precipitate. The yield of the copolymer was 90%, and the composition of the copolymer was 2,6-diprenylphenol:2,6-dimethylphenol≈1:2.2 (unit molar ratio) based on the quantitative determination of double bonds. The molecular weight of the produced polymer was 24,000. Example 3 Triethyleneamine 30ml in chloroform 300ml,
After adding 270 mg of cupric chloride, 2,6-diprenylphenol and 2,6-dimethylphenol were copolymerized in the same manner as in Example 2. The polymerization was completed in 60 minutes, and the yield of the copolymer was 86%, the composition was 2,6-diprenylphenol:2,6-dimethylphenol=1:2.0 (unit molar ratio), and the molecular weight was 16,400. Example 4 2,6-bis(2-butenyl)phenol was synthesized in the same manner as in Example 1 using trans-1-chloro-2-butene as the allyl halide. The yield was 58%. The characteristic absorptions of the infrared absorption spectrum are 3450, 1930, 1860, 1780, 1675,
1210, 970, 870, 750 cm ^-1 , and the NMR spectrum (δ, CCl ₄ ) is 1.70 (6H, d, -CH ₃ ), 3.28
(4H, d, -CH ₂ -), 5.03 (1H, -OH), 5.40 ~
5.72 (2H), 6.65-7.20 (3H, proton of benzene nucleus) ppm. 2,6-bis(2-
(butenyl)phenol and 2,6-dimethylphenol were copolymerized in a benzene solvent at room temperature in the same manner as in Example 2. Copolymer yield: 92%, composition: 2,6-bis(2-butenyl)phenol:
2,6-dimethylphenol = 1:1.9, molecular weight
It was 23200. Example 5 2,6-biscinnamylphenol was synthesized in the same manner as in Example 1 using cinnamyl chloride as the allyl halide. The yield was 42%. 2,6-biscinnamylphenol and 2,6-dimethylphenol synthesized as described above were copolymerized in the same manner as in Example 2 in a benzene solvent. The yield of the copolymer was 88%, and the composition was 2,6-
Biscinnamylphenol:2,6-dimethylphenol=1:2.5, molecular weight 19,600. Application example Copolymer of 2,6-diprenylphenol and 2,6-dimethylphenol synthesized in Example 2
Dissolve 1.0 g in 30 ml of benzene, purify the reaction vessel with nitrogen, and then heat to 60°C. Separately prepare 10 ml of a benzene solution containing 6.9 mg of azobisisobutylnitrile as a radical polymerization initiator and 10 ml of a benzene solution containing 0.5 ml of styrene, and add drop by drop to the reaction vessel over about 20 hours while stirring and blowing nitrogen gas. After further stirring at 60° C. for 5 hours, the reaction solution was added dropwise to 1 portion of methanol acidified with hydrochloric acid to obtain a white precipitate of a graft copolymer.

Claims (1)

[Scope of Claims] 1. An allyl group in a side chain with a molecular weight of 500 to 30,000, consisting of the following repeating unit (), or consisting of a repeating unit () and a repeating unit () and containing 28% or more of the repeating unit () Polyphenylene ether with. (In the formula, R ¹ and R ² represent a hydrogen atom, a lower alkyl group, or a phenyl group, and R ³ and R ⁴
represents a lower alkyl group. Polyphenylene ether according to claim 1, characterized in that the repeating unit ( ) 2 is derived from 2,6-diallylphenol.