JPS6323906A - Novel living polymer - Google Patents

Abstract

PURPOSE:To obtain an anionic living polymer of a monomer protected with a protective group which can be eliminated only by treatment with a mineral acid or a base, by polymerizing a Schiff base of a specified vinyl monomer in the presence of an anionic polymerization initiator. CONSTITUTION:A vinyl monomer (a) of formula I (wherein R' is H or CH3) is reacted with about 1mol, per mol of component (a), of a 2,6-substituted aniline derivative (b) of formula II (wherein R<2-3> are each alkyl) at 70-90 deg.C for 1-10hr in the presence of, optionally, 0.1-10mol%, based on component (a), acidic catalyst to obtain a Schiff base (A) of an aromatic vinyl compound. Component A is polymerized at -100 deg.C to room temperature for 0.1-24hr in an inert gas atmosphere or a vacuum in the presence of an anionic polymerization initiator (B) [e.g., (alpha-methylstyrene oligomer) potassium salt] to obtain the title polymer having a number-average MW of 500-500,000 and a weight-average MW to number-average MW ratio of about 1 and having repeating units of formula III (wherein n>=2).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel morphing polymer of an aromatic vinyl compound.

[Conventional technology]

Anionic living polymers of vinyl monomers having reactive groups such as formyl groups and carboxyl groups in their molecules cannot be directly obtained because of the active hydrogen and carbonyl carbon in the reactive groups.

However, for aromatic vinyl monomers that have a formyl group, which is one of the reactive groups, the formyl group in the molecule is converted into a substituent consisting of an imidazolidine skeleton in advance, and then the anionic polymerization initiator is used. Anionic living polymers of aromatic vinyl monomers having protected formyl groups have been obtained (Kobunshi Proceedings, Vol. 34, No. 2, p. 195 (1985)).

[Problem that the invention seeks to solve]

Generally, linear polymers having formyl groups in side chains, such as poly(4-formylstyrene) and polyacrylaldehyde, are originally tetrahydrofuran (hereinafter abbreviated as THF).

), but it becomes soluble when left standing.
It is known that the solubility decreases over time and eventually becomes insoluble in the above organic solvent, and that the reactivity when converting the formyl group in the polymer to another polar group by reacting with an appropriate compound decreases. It is being

This insolubilization is caused by the formation of hemiacetal bonds between formyl groups in the side chains of the same polymer molecule or different polymer molecules, resulting in the formation of intramolecular or intermolecular crosslinks. For this reason, linear polymers with formyl groups in their side chains can be used not only as functional polymers themselves, but also as raw materials for the synthesis of functional polymers in which the reactive formyl groups are substituted with other functional groups. In this case, the side chain formyl groups in the polymer should be protected with an appropriate protecting group until immediately before use to prevent insolubilization or reduction in reactivity due to cross-linking between formyl groups. is desirable.

The above-mentioned suitable protecting group used for protecting the formyl group is one that can simultaneously satisfy the following two requirements.

(2) The protecting group does not react with the anionic polymerization initiator, and when it has a formyl group protected by the protecting group, the nil monomer forms an anionic living polymer.

■ The protecting group in the anionic living polymer obtained in (■) above can be removed by treatment with methanol, etc., or purification treatment with re-extraction.
・There is no , and it can only be removed by removing the protective group using a mineral acid or base.

The substituent consisting of an imidazolidine skeleton, which is a protecting group for the formyl group described above, satisfies the above requirement (1), but some of the protecting groups are removed from the resulting living polymer by treatment with methanol or polymer purification treatment.
As a result, a phenomenon in which insoluble portions were formed over time was observed, and the above requirement (2) was not satisfied.

[Purpose of the invention]

The present invention aims to synthesize an anionic living polymer of nine monomers by protecting the formyl group of an aromatic vinyl monomer having a formyl group with a protecting group that cannot be removed under conditions other than the above-mentioned specific treatment. purpose.

[Ninth way to solve the problem]

(Summary of the Invention) As a result of extensive research, the present inventors have discovered that the formyl group of an aromatic vinyl monomer can be protected by converting it into a Schiff base with a 2,6-substituted aniline derivative. A living polymer having a repeating unit of an aromatic vinyl monomer having a structure is generated, and the Schiff base structure in the living polymer stably exists without decomposing except for a specific treatment using a mineral acid or base. They discovered this and completed the present invention.

That is, the present invention.

(In the formula, R1 is a hydrogen atom or a methyl group, R2 and R3 are the same or different alkyl groups, and n is an integer of 2 or more.

) Novel folding polymer (1) with repeating units
The gist is:

(Method for producing living polymer) The living polymer (I) according to the present invention has the following formula:
represents a hydrogen atom or a methyl group. ), the vinyl monomer obtained by contacting the vinyl monomer (ff)t- with a 2,6-substituted aniline derivative represented by the formula (in the formula, R% R3 represents the same or different alkyl group) PG can be produced by polymerizing a Schiff base in the presence of an anionic polymerization initiator.

Specific examples of the vinyl monomer (II) include 4-formylstyrene and 4-formyl-α-methylstyrene.

R2 and R3 in the formula of the 2,6-substituted aniline derivative used to protect the reactive group of the vinyl monomer (n) are methyl, ethyl, n-propyl, 1so-propyl, n-butyl, 1so It is a lower alkyl group such as -butyl, t-butyl, etc., and R2 and R3 may be the same or different.

Vinyl monomer (I[),! The reaction with the = 2, 6-[7-niline derivative is carried out under heating at 70 to 90°C for usually 1 to 10 hours. Contact between the two may be carried out in a solvent or in an atmosphere of an inert gas such as nitrogen gas. Suitable solvents include benzene, toluene,
Examples include m-xylene'4 tv hydrocarbons, chloroform, carbon tetrachloride, halogenated hydrocarbons such as dichloroethane, and the like.

Further, in the contact between the two, an acidic catalyst such as para-toluenesulfonic acid may be added as necessary.

The contact ratio of both is 2 to vinyl monomer (II).
．． It is desirable that the amount of the 6-substituted aniline derivative be 1 times the mole, but it may be more than 1 times the mole. In addition, the amount of acidic catalyst used is usually 0.1 to 1 per vinyl monomer (1 [)].
It is 0 mol%.

As a result, the two are condensed to form an aromatic vinyl compound having a thick base structure (hereinafter referred to as the vinyl compound), but the vinyl compound is then converted into an anion in the presence of an anionic polymerization initiator. The pasting polymer (1) of the present invention is obtained by polymerization.

Suitable anionic polymerization initiators used in the present invention include naphthalene sodium salt, naphthalene potassium salt, (α-
Examples include sodium salt (methylstyrene oligomer), potassium salt (α-methylstyrene oligomer), and cumyl potassium salt.

The anionic polymerization is carried out at -100°C to room temperature, preferably at a low temperature of -30°C or lower, particularly preferably at -50°C to room temperature.
It is carried out at a low temperature of -100°C for 0.1 to 24 hours. Although the polymerization reaction may be carried out without a solvent, it is preferably carried out in the presence of a solvent. Suitable solvents include THF, hexane, toluene, cyclohexane, pentane, benzene and the like, and two or more of these may be used in combination.

Furthermore, the polymerization system must be maintained in an inert gas atmosphere or under reduced pressure, particularly preferably under high vacuum, free of moisture and oxygen that would interfere with the polymerization reaction.

The molecular weight of the living polymer (1) is the vinyl compound/
It can be controlled by changing the ratio of anionic polymerization initiators, and by increasing the ratio, the molecular weight can be increased accordingly.

The polymer (I) thus obtained usually has a molecular weight of about 5
00 to about soo, ooo, preferably about 2.000 to about 200,000%, particularly preferably about 5.000 to about 1f
l) It has a number average molecular weight of 0,000 and has an extremely narrow molecular weight distribution with a ratio of weight average molecular weight/number average molecular weight close to 1.

〔Effect of the invention〕

When the pasting polymer CI) of the present invention is brought into contact with a mineral acid such as hydrochloric acid or sulfuric acid or a base such as sodium hydroxide or potassium hydroxide, the Schiff base, which is a protective group, easily decomposes to formyl groups. Regenerated and vinyl monomer (I
The polymer of I) is provided.

The living polymer (1) according to the present invention has a protective group that does not come off by treatment with methanol, ethanol, etc., purification treatment by reprecipitation in water, etc., compared to a living polymer using an imidazolinyl group as a protective group for a formyl group. , the protective group can be removed only by a protective group removal treatment using a mineral acid or base.

The thus obtained polymer from which the protective groups have been removed is useful as a functional polymer with a well-defined linear structure without cross-linking between side chain formyl groups, and all of its reactive substituents are replaced by other polar groups. The present invention will be specifically explained below with reference to Examples, but the present invention is not limited thereto.

〔Example〕

(Polymerization apparatus used for anionic polymerization) After freezing, the anionic polymerization initiator solution and monomer solution used for anionic polymerization were degassed in a high vacuum line and sealed in an Alpul with a break seal.

Anionic polymerization is carried out in a drawing in which a flask connected to a high vacuum line is connected to the above ampoules containing multiple anionic polymerization initiator solutions and monomer solutions, and a branch pipe for taking out the waste anionic initiator solution after cleaning the system. using the device,
It was done in the following way.

First, flask 1 was kept at 10-5 mmHg for 5 hours to degas it, and the vacuum line 6 was sealed at point A. Then, the seal of ampoule 2 containing one anionic polymerization initiator solution was broken, and flask 1 was removed. The inside of the system containing the liquid was thoroughly washed and led to a branch pipe 5, which was then sealed off at point B. Next, the flask 1t was cooled to -78°C, the seal of the ampoule 3 containing the second anionic polymerization initiator solution cooled to -78°C was broken 9, and the anionic polymerization initiator was introduced into the flask 1. Four ampoules of the monomer cooled to -78°C were introduced into flask 1 in the same manner and reacted for 20 minutes. The resulting polymer was post-treated and then subjected to characterization.

(Synthesis and identification of N-(4-vinylbenzylidene)-2,6-diethylphenylamine (abbreviated as BDA, the same applies hereinafter)) 4-formylstyrene (equal mole of 2 to CH2-FST) was added to the reactor. .025% of 1 mole para-toluenesulfonic acid to 6-dinitylaniline and PST
A benzene solution was added, and the reaction was carried out for 5 hours at the reflux temperature of benzene. The obtained product was distilled under reduced pressure to obtain N-(
4-vinylbenzylidene)-2,6-diethylphenylamine (abbreviated as BDA).

Same below. ), and further Grignard reagent (C2H3
By adding OM2MgCI and vacuum distilling, 5
Purified BDA was obtained with a yield of 4%.

BDA' HNMR (60 MHz % CCl J,
BDA was confirmed to have the following structure based on the chemical shift value shown below.

1.10 ppm (t; 6H, -CH2-C
H3), 2.4 appm (q; 4H, -CH2-C
H,), 5.19-5.771) 1) m(2d; 2H,
J=11Hz, 18Hz.

CH2= ), 6.53-6.93 ppm (m;
3H, N-C, H3), 6.53-6.93 pp
m (m; IH, CH=), 7.35-7.92 p
pm (m; 4H, C6H4-CH=N-), 8
．． 17pm) m (,S; IH; C6H4-CH
=N-).

(Synthesis and identification of living polymer of BDA) Using various anionic polymerization initiators shown in Table 1, BDA was
Polymerization was carried out at -78° C. for 20 minutes in F. In both cases, the color exhibited a slightly blackish red color characteristic of the polymerized exfoliating anion.

Poly[:N-(4 -vinylbenzilitine) -2,6-diethylphenylamine] (abbreviated as PBDA, same hereinafter)
was obtained quantitatively.

1HNMR of PBDA (60MHz in 1CCZ4,
The results of TMS standard analysis and IR analysis are shown below.

'HNMR: 1. OOppm(s: 6H,C
H2CHρ, 2.03 ppm (lit: 4 H
, -CH2-CH3), 0.73-2.70 ppm
(broad; 2H, -CH2-CH-), 0.7
3 to 2.70 ppm (broad: IH, -
CH2-CH-), 6.20-7.9 5 ppm (
broad: 3H.

= N −C6Hρ, 6.20-7.95 ppm (b
road: 4H, C6H4-CH=N-), 8.
10 PPm (8: IH, C6H4-Cdan=N-
C6H3).

IR: 2974 and 2876 am-1 (CH3), 1
645 cm (CH=N), 1610 and 151
1 am (benzene ring endoskeleton), 830 From these analysis results, PBDA! It was confirmed that Ii had all of the following structures and that the Schiff base structure as a protecting group was not removed at all.

(Left below) V P O (Vapor Pressure Osmo
Table 1 shows the results of measuring the number average molecular weight of PBDAO and comparing it with the number average molecular weight calculated from the molar ratio of BDA/anionic polymerization initiator. It can be seen that the two agree quite well.

Regarding PBDA, GPC (Gel
Permeation Chromatography
y) As a result of measurement, it was confirmed that the polymer had an extremely narrow molecular weight distribution. These analysis results proved that the polymer obtained by anionic polymerization of BDA is a living polymer having repeating units of BDA.

PBDA is THF, benzene, toluene, xylene,
Soluble in ethyl acetate, methyl ethyl ketone, chloroform, carbon tetrachloride, dichloromethane, diochitin, n
-Hechitin was insoluble in diethyl ether, ethanol, methanol, and water.

(Changing over time of protecting groups in PBDA) After leaving PBDA in an atmosphere of 20°C and relative humidity of 65°C for 10 days, the solubility in the above solvent that dissolves PBDA was observed, and no insoluble portion was observed. . As a result of ``HNMR, analysis, and one-pack analysis of this PBDA, the presence of a formyl group was not observed, and it was confirmed that the Schiff base structure, which is a protective group, completely disintegrated when left standing over time.

(Synthesis and identification of poly(4-formylstyrene) (abbreviated as PFST, the same applies hereinafter)) PBDA was added to T containing 8.3 ml of 36% hydrochloric acid.
Dissolve in 100ml of HF to make a 1.6% solution and heat at 50°C.
By heating for 3 hours, the Schiff base, which is a protective group for the formyl group, was decomposed and removed, yielding PFST. P
After FST was purified by reprecipitation method, 'HNMR and I
It was analyzed using R and confirmed to have the following structure.

PFST is soluble in THF, methyl ethyl ketone, chloroform, dichloromethane, N,N-dimethylformamide, n-hexyl ether, cyclohexyl ether, carbon tetrachloride, xylene, toluene, ethyl acetate, benzene, acetone, pyridine. , diochitin was insoluble in ethanol, methanol, and water.

(Left below) Table 1 Explanation of abbreviations of anionic polymerization initiator (In) (α-MeS
t) 4 to 2: (α-methylstyrene oligomer)
Potassium salt (α-MeSt)4Na2' (α-methylstyrene oligomer) sodium salt, note) 1) Measured in benzene using VPO.

2) Calculated based on the molar ratio of the charged monomer and polymerization initiator.

[Comparative example]

(4-(2-(1,3-dimethylimidazolidinyl))
Synthesis and Identification of Styrene Pasting Polymer) A monomer protected by converting the formyl group of a styrene monomer having a formyl group into a substituent consisting of an imidazolidine skeleton, that is, 4-("2-(1,3-dimethylimidazolidinyl) )] Styrene (hereinafter abbreviated as pDMIs) is FS
N*N'-dimethylethylenediamine in an equimolar amount with respect to T and FST, and 1 mol of paratoluenesulfonic acid with respect to FST were dissolved in benzene to give a concentration of 0.05%, and the mixture was heated under the reflux temperature of benzene for 2 hours. After the reaction, the product was obtained by distillation under reduced pressure. The obtained pDMIS was purified by adding Grignard reagent (C, H5CH2MgC) and vacuum distillation.

Poly(pDMIs) was quantitatively obtained by anionically polymerizing pDMI S in exactly the same manner as in the examples and by treating the resulting PDMIS polymer with methanol. Poly(pDMIs)'HNMR, and IR.

It was analyzed and confirmed to have the following structure.

(Left below) Poly(pDMIs) is soluble in cyclohexitine, diethyl ether, THF, benzene, toluene, xylene, methyl ethyl ketone, ethyl acetate, chloroform, carbon tetrachloride, diochitin, pyridine, and N,N-dimethylformamide. It was insoluble in n-hexitine, acetone, dichloromethane, and water.

(B9 Change over time of protecting groups in (pDMIs)) After the above poly(pDMIs) was left in an atmosphere of 20°C and relative humidity of 65°C for 10 days, the solubility in the above solvent in which poly(pDMIs) was dissolved was determined. As a result of observation, insoluble portions were observed, and it was confirmed that the solubility had decreased. As a result of 'HNMR analysis and ITL analysis of this poly(pDMIs), in addition to the peak of the substituent having an imidazolidine skeleton, which is a protecting group, a peak due to formyl group was observed.

From these results, it was confirmed that the protecting group, the Okira group having an imidazolidine skeleton, decomposes when left standing over time, the formyl group is regenerated, and the polymer becomes insolubilized.

[Brief explanation of the drawing]

The figure is a conceptual diagram of an example of an apparatus for carrying out anionic polymerization in the present invention. DESCRIPTION OF SYMBOLS 1... Flask, 2, 3... Ampoule filled with anionic polymerization initiator solution, 4... Ampoule filled with monomer solution, 5... Branch pipe, 6... Vacuum line,
7. River Kotuku, 8. Magnet.

Claims (1)

[Claims] General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R^1 is a hydrogen atom or a methyl group, R^2 and R
^3 represents the same or different alkyl group, and n represents an integer of 2 or more. ) A novel living polymer with repeating units.