JPH0258505A - Method for anionic polymerization - Google Patents

Abstract

PURPOSE:To obtain a telechelic polymer having functional groups reactive with a crosslinking agent at both ends and a narrow molecular weight distribution by using a novel anionic-polymerization initiator prepared by reacting a special alpha-substituted styrene derivative with a specific organometallic compound. CONSTITUTION:An anionic polymerizable monomer is subjected to anionic polymerization using a compound prepared by reacting (A) an alpha-alkylstyrene derivative expressed by formula I (R1 is 1-6C alkyl; R2 is direct bond or 1-6C alkylene; R3 is OH-protecting group) or diphenylethylene derivative expressed by formula II (R4 is H or 1-6C alkyl) with an organometallic compound expressed by the formula MR5 (M is group Ia metallic element of the periodic table; R5 is 1-6C alkyl or cumyl) or (B) a compound obtained by reacting the compound expressed by formula I with the organometallic compound expressed by the formula MR5 and then reacting the resultant compound with a diphenylethylene (derivative) expressed by formula III as an anionic polymerization initiator.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anionic polymerization method using a novel anionic polymerization initiator.

In recent years, there has been a strong demand for high solids in the field of base resins for paints. As is well known, in order to achieve high solidity, it is necessary to reduce the molecular weight of the base resin so that it maintains a viscosity that allows coating at high concentrations. However, lowering the molecular weight of the base resin using existing technology is difficult because i) the molecule 1 distribution is wide, so blindly lowering the molecular weight will cause the formation of extremely low molecular weight components, which will have a negative effect on coating workability and physical properties of the coating film;
ii) Due to the increase in terminal free chains in the coating film, desirable physical properties of the coating film cannot be obtained.

In other words, when the molecular weight of resin obtained by radical polymerization is reduced, extremely low molecular weight molecules are produced because the molecular weight distribution is wide, and it is possible that extremely low molecular weight molecules do not contain functional groups that can serve as crosslinking points. There is sex.

Anionic polymerization, particularly anionic living polymerization, yields polymers with a relatively narrow molecular weight distribution, and the molecular weight can be easily controlled, so it is suitable as a method for synthesizing lower viscosity resins for high solid paints. On the other hand, in order to use it as a paint (H resin), it is necessary to have a functional group in its molecular chain that can react with a crosslinking agent.Moreover, in order to obtain a cured coating film with excellent physical properties, It is desirable to have as few (two) such functional groups in the same molecular chain.

However, for example, a dianionic living tetramer obtained by reacting α-methylstyrene with Na metal is used as an initiator, and a functional group is introduced into the growing terminal of the polymer obtained by growing it from two growth starting points by an anionic polymerization method. When trying to obtain a multifunctional polymer by using a monomer, if one of the growing ends causes a termination reaction, only a monofunctional monomer will be obtained.

Therefore, the present inventors first investigated α with a protected functional group.
- Using a dianionic living telomer obtained by reacting alkyl styrene with an alkali metal as an initiator, a functional group is introduced into the growing terminal of the polymer obtained by growing it from two growth initiation points by an anionic polymerization method, and the polymer chain is We have proposed an anionic polymerization method for producing multifunctional polymers having functional groups at the center and at both ends. See patent application No. 62-80399. However, the preparation of the initiator used in this process is relatively complex and requires the use of the alkali metal itself, which is difficult to handle.

Therefore, the present inventors used a compound obtained by metallizing an α-substituted styrene derivative having a protected functional group (hydroxy-containing group) with an organic alkali metal such as n-butyl lithium as an initiator. We considered introducing a functional group to the growing end of the polymer obtained by polymerization. Although the initiator used here has only one growing point, its production is much easier and simpler than the production of the dianionic telomer proposed earlier by the present inventors, and the initiator after polymerization By removing the protective group of the originally protected functional group, a bifunctional polymer having a narrow molecular weight distribution and having functional groups capable of reacting with a crosslinking agent at both ends can be obtained.

TECHNICAL FIELD The present invention relates to a method for anionically polymerizing monomers capable of anionic polymerization.

The anionic polymerization initiator used in the present invention is obtained from an α-alkylstyrene derivative of the following formula (1) or a diphenylethylene derivative of the formula (U).

where R+ is C1-Cs alkyl.

R2 is a direct bond or C1-C6 alkylene.

R3 is a hydroxy protecting group.

R4 is hydrogen or C1-C6 alkyl.

The anionic polymerization initiator is added to the α-alkylstyrene derivative (1) or diphenylethylene derivative (II),
Formula MR5 (M is a metal element of the Ta group of the periodic table, R5
is obtained by reacting Cs-C6 alkyl or cumyl).

When a compound obtained by reacting the compound of formula (1) with IMIJ thium is used as an initiator to anionically polymerize (meth)acrylic acid ester, carbonyl addition at the active site occurs as a side reaction in the initiation stage. Otherwise, a polymer with an extremely small molecular weight may be mixed into the produced polymer, making it impossible to obtain a polymer with a narrow molecular weight distribution. In such a case, after reacting the α-alkylstyrene derivative of formula (1) as an initiator with organolithium, further reacting diphenylethylene of the formula (wherein R4 is the same as above) or a derivative thereof. You can use the compound obtained by Thereby, in anionic polymerization of (meth)acrylic acid ester, the side reaction can be prevented using a highly versatile anionic polymerization initiator having lithium as a counter cation.

The anionic polymerization reaction of the present invention can be carried out by a conventional anionic living polymerization method, except for using the above-mentioned novel anionic initiator.

After the polymerization reaction has been carried out for a predetermined period of time, a proton donor such as a lower alkanol is added to react with the growing end of the polymer to stop the growth reaction.

By reacting a reagent for introducing a functional group that can react with a cross-linking agent instead of a proton donor, the growing end is deactivated and, at the same time, a functional group that can react with the cross-linking agent is introduced into the end. Can be done.

Finally, by removing the protecting group of the hydroxy group of the α-alkylstyrene derivative of formula ([) or the diphenylethylene derivative of formula (II) to regenerate the hydroxy group, a functional group capable of reacting with a crosslinking agent is added to both ends. A telekilic polymer with a narrow molecular weight distribution is obtained.

Among the α-alkylstyrene derivatives of the formula (1), compounds having a trialkylsilyl group as a protecting group for a hydroxyl group are described in Japanese Patent Application No. 80397/1983 by the present inventors. These can be produced by reacting a corresponding α-alkylstyrene derivative having a free hydroxyl group with trialkylchlorosilane or hexaalkylsilazane.

Here, the hydroxy group-protecting group refers to a group that can be selectively removed under relatively mild conditions such as hydrolysis to regenerate the hydroxy group. Such protecting groups and their removal methods are well known, for example, in the field of peptide synthesis.

Specific examples of the α-alkylstyrene derivative of formula (1) include p-(2-trimethylsiloxyethyl)-α-methylstyrene, p-(2-4ethylsiloxyethyl)-
α-methylstyrene, p(2tert-butyldimethylsiloxyethyl-α-methylstyrene (BOMS),
Examples include p-(2-liptylsiloxyethyl)-α-methylstyrene, p-(2-propyldimethylsiloxyethyl)α-methylstyrene, and p(2tert-butoxyethyl)-α-methylstyrene.

The diphenylethylene derivative of formula (II) is a new compound.

Therefore, these compounds are not limited to the methods of use of the present invention. For example, it is known that diphenylethylene does not show homopolymerizability but copolymerizes with small molecules such as styrene (Bull.

Chew, Soc, Jpn, 40, 2659
(1967) Therefore, this compound can also be used as a monomer for synthesizing various copolymers.

Of the compounds represented by formula (II), p-(2ter
t-Butyldimethylsiloxyethyl)diphenylethylene ([[-a) is p- according to the following scheme, (the following margins) (V-a) (V[-a) (■-a) (■ 01; a) It can be produced by synthesizing (2-hydroxyethyl)diphenylethylene (■-a) and reacting it with tert-butyldimethylchlorosilane.

p-(2-)liptylsiloxyethyl)diphenylethylene (IT-b) can be obtained by reacting compound (■-a) with hexamethyldisilazane.

Furthermore, p(2tert-butoxyethyl)diphenylethylene (n-c) can be synthesized by reacting compound (■-a) with isobutylene.

Diphenylethylene derivatives other than those listed above are also corresponding diphenylethylene derivatives having a free hydroxyl group (■)
It can be produced according to the above synthetic scheme by reacting the corresponding trialkylchlorosilane, hexaalkyldisilazane, or olefin.

The anionic polymerization initiator of the present invention is the α-alkylstyrene derivative or diphenylethylene derivative ([)
is obtained by reacting with an organic alkali metal of formula MR5. Specific examples of organic alkali metals of formula MR5 include n-, sec or tert-butyllithium, cumyl potassium, cumyl cesium, and the like. The organic alkali metal is compound vA(1) or (I
The reaction is carried out in an amount of 0.5 to 1.2 mol based on I). If it is used in excess, a polymer will also be generated from unreacted organic alkali metal, so it should be avoided. The reaction was carried out at -100°C to +50°C in a solvent used in the polymerization reaction described below.

The reaction can be carried out preferably at -100°C to -40°C in the same atmosphere as the polymerization reaction described later for 10 minutes to 24 hours.

The product obtained from the reaction of said compound IM (1) with an organolithium compound was further reacted with diphenylethylene of formula (III) or its CI-C6 alkyl derivative such as p-methyldiphenylethylene. After that, it can be used as an anionic polymerization initiator in the present invention. Compound (III) is suitably used in an amount of 1 to 1.5 mol based on compound (r).

Specific examples of monomers that can be polymerized with the initiator of the present invention include
Styrene, o-, m- or p-methylstyrene, α-
Methylstyrene, o-, m- or p-ethylstyrene, o-, m- or p-propylstyrene, o-, m-
or p-7' (-lustyrene, o-, m= or p
- Styrene derivatives such as hexylstyrene, 1,3-bucdine, isoprene 12,3-dimethyl-1,3-butadiene, 2-methyl-1,3-butadiene, 3,4-dimethyl-I.

3-pentadiene, 3,4-dimethyl-], C3 hexadiene, 4,5-diethyl-1,3-octadiene.

Phenyl-1,3-butadiene, 2tert-butyl-1
, 3-butadiene and other dienes, methyl (meth)acrylate, ethyl (meth)acrylate, (meth)acrylic flln-butyl 1 i-butyl (meth)acrylate,
(meth)acrylic esters such as phenyl (meth)acrylate, benzyl (meth)acrylate, and (
Meta)acrylonitrile is mentioned.

The first reaction is generally carried out in a medium that is inert to the m-combination reaction. Specific examples of solvents that can be used include diethyl ether and methyl ethyl ether.

1. Ethers such as 4-dioxane and tetrahydrofuran, aromatic hydrocarbons such as benzene, toluene and xylene, pentane, hexane and heptane.

Examples include aliphatic hydrocarbons such as cyclohexane. Further, two or more of these solvents can be used in combination. Furthermore, there is no particular limit to the m concentration, but it is 5 to 30%.
It is generally done in

The mixing temperature can be arbitrarily selected within the range of -100°C to +50°C, but in the case of diene spinning wheel bodies, it is -40°C.
~50°C, and in the case of styrene-based and acrylic acid-based monomers, the temperature is preferably 50°C or less, particularly within the range of -100°C to -50°C.

The polymerization atmosphere is an inert gas atmosphere, under reduced pressure, preferably under high vacuum, and the polymerization time depends on the monomers used,
Depending on the solvent 1 polymerization temperature 2 polymerization concentration and the molecular weight of the resulting polymer, 10 minutes to 48 hours are employed.

Moreover, with this initiator, random copolymers and block copolymers can also be produced using a known anionic living polymerization method.

Since the propagating end of the polymer thus obtained is "living," a polymer with trialkylsiloxy or alkoxy ends can be obtained by adding a protic solvent such as methanol, and a polymer with a trialkylsiloxy or alkoxy end can be obtained by reaction with an appropriate external reagent. Hydroxyl group, carbogyyl group, amino group on the growing terminal side of
Epoxy group.

Functional groups such as mercapto groups, sulfonyl groups, halogens, vinyl groups, and vinylidene groups can be introduced.

Specific examples of external reagents for introducing hydroxyl groups into the terminals of polymers include formaldehyde, acetaldehyde,
n-butyraldehyde, chloral, propionaldehyde, isobutyraldehyde, n-valeraldehyde,
Aldehydes such as isovaleraldehyde, n-caproaldehyde, n-heptaldehyde, and stearaldehyde, ketones such as acetone, methyl ethyl ketone, and diethyl ketone, ethylene oxide, propylene oxide, trimethylene oxide, butylene oxide, bentrene oxide, cyclohexylene oxide.

Examples include alkylene oxides such as styrene oxide and derivatives thereof, and oxygen.

Carbon dioxide is an example of an external reagent for introducing a carboxyl group to the end of a polymer.

External reagents for introducing halogen into the terminals of polymers include chlorine, bromine, bisbromomethyl ether, bisbromomethyl ether, and the like.

External reagents for introducing amino groups at the terminal ends of polymers include imines such as ethyleneimine, propyleneimine, and cyclohexeneimine.

In addition, to the terminal of the polymer, for example, carbon disulfide, ethylene sulfide, propylene sulfide.

A mercapto group can be introduced using sulfur or the like, a sulfonyl group can be introduced using sulfuryl chloride or the like, and a functional group such as an epoxy group can be introduced using epichlorohydrin or the like.

Thereafter, if the protecting group for the hydroxy group contained in compound (1) or (II) is removed by a conventional method such as hydrolysis, a telekilink having a hydroxy group at one end of the polymer and a functional group at the other end. You can get a polymer.

Examples of the present invention are shown below. The physical properties of the polymers in Examples were measured by the following method.

The molecular weight and molecular weight distribution of the polymer were measured using a GPC2 vapor pressure osmometry equipped with a differential refractometer and an ultraviolet absorption photometer.

Quantification of terminal carboxy groups is performed using Anal, Chem, +
29+232 (1957), by potentiometric titration using a benzene/methanol solution of potassium methoxide in methyl isobutyl ketone as the titration reagent.

Example 1 THF 13 at room temperature using break seal method under high vacuum
31rLe, I) THF solution solution of (2-tert-butyldimethylstyrene (BOMS), 3 x 10-2N, No. 11.9) was added, and further n-butyllithium was added. (2,3X 10
-2N, 11.8d) was added. The reaction system exhibited a reddish brown color characteristic of α-methylstyryl anion. After reacting for 1 hour, 8.6 parts of α-methylstyrene was added, and the temperature was reduced to -78°C.
The mixture was cooled to a temperature of 50% to initiate a polymerization reaction. After reacting for 1 hour, a small amount of methanol was added to stop the reaction. The number average molecule i1Mn of the obtained polymer (polystyrene equivalent, GPC
) and molecular weight distribution M w / M n are; each 1
6,] X l O' and 1.04.

Yield 100% Example 2 THF1 at -78°C using break seal method under high vacuum
09m! n-butyllithium (2,9X10-IN
, 6.35d), and then add BOMS THF solution (
80MS3.50mf, THF6.80), 1
．． The reaction was allowed to proceed for 5 hours. Next, methyl methacrylate io,
4mi was added to start the polymerization reaction. After 2 hours of reaction,
The reaction was stopped by adding a small amount of methanol. The Tn (GPC) and Ding wealth 1 of the obtained polymer are each 1
．． 5xlO' and 4°25. Yield: 100% Example 3 Using the break-seal method under high vacuum, 80% of THF was added to 130%.
After adding 3.25 ml of 0MS, the temperature was raised to -40°C, n-butyllithium (0.29N, 7.00d) was added, and the mixture was reacted for 1 hour. Next, 1,1-diphenylethylene (D
PE) in THF solution (DPE2.Oy!.

THFIOd) was added and reacted for 30 minutes. Furthermore-
The mixture was cooled to 78°C, 10°C of methyl methacrylate was added, and after reacting for 1 hour, a small amount of methanol was added to stop the reaction. The obtained polymer (theoretical molecular weight Mk=6.
5 x 103) Mn (GPC) and M w /
M n are 6.8 x 103 and 1,1 respectively
It became 7. In addition, the number average molecular weight Mn (VPO) determined by vapor pressure osmometry (VPO) is 8.6X10
It became 3. IH-N HR measurement showed that the numbers of 80MS units and DPE units contained per molecule of polymer chain were 2.3 and 0.8, respectively.

Example 4 Using the argon atmosphere nib break seal method, T at 58 °C
HF28.0j? n-butyllithium (1,82N,
227) and 3219 g of 80M were added and reacted at -25°C for 2 hours. Further, 113 g of DPE was added at -25°C and reacted for 1 hour. Next, 2.01 ml of methyl methacrylate was added at -78° C., and after reacting for 1 hour, a large excess of carbon dioxide was added to stop the reaction. The obtained polymer (
Mk=5゜0X103) Mn (GPC) and Mw
/Mn are 5.9 X L O3 and 1.3, respectively.
It became 4.

(The terminal carboxylate was acidified by reprecipitation purification after treatment with a dilute acid in a benzene solution. The polymer titration, vapor pressure osmometry, and I H-NMR measurement revealed that the carboxylate The functionality of the acid was 0.97, and the numbers of 80MS units and DPE units contained per molecule of polymer chain were 1.1 and 0.9, respectively. (Carboxylic acid concentration = 1.47Xio-' Mol/g, Mn (VPO
) = 6.6 X 103) Yield 100% By further blowing hydrogen chloride gas into acetone,
Alternatively, it was confirmed by IH-NMR that the protecting group was completely removed by adding hydrobromic acid.

Example 5 29.1 g of metallic magnesium powder was placed in a 21 flask equipped with a 2-hydroxyethyl)diphenylethylene stirrer, a reflux condenser, and a dropping funnel, and 101 parts of bromobenzene and 500 d of THF were added from the dropping funnel.
A Grignard reagent was prepared by adding dropwise and reacting at 65°C. After cooling to 30°C, 199 g of p-bromoacetophenone and 200 g of THF were added. d was added dropwise from the dropping funnel in the same manner to cause a reaction. After the reaction was completed, dilute hydrochloric acid was added and ether extraction was performed to obtain an intermediate α-methyl-p-bromobenzhydrol. This product was dehydrated with potassium hydrogen sulfate and distilled under reduced pressure to obtain p-bromodiphenylethylene. 1190% Magnesium powder 20.4% again in the same reaction vessel as above
g, and a solution of 150 g of p-bromodiphenylethylene and 500 mf of THF was added dropwise from the dropping funnel.
A Grignard reagent was prepared by reacting at 5°C. After cooling to 0°C, 100% of ethylene oxide was added dropwise.
Made it react.

After the reaction was completed, dilute hydrochloric acid was added, ether extraction was performed, and the mixture was distilled under reduced pressure to obtain p-(2-hydroxyethyl)diphenylethylene. Yield 185% Identification by gas chromatography IR, IHN MR
I went there.

Example 6 In a 1e flask equipped with a stirrer and addition funnel, DM
F200me, t-butyldimethylchlorosilane 16.
Add 8 g and 7.6 g of imidazole, and add DM to this.
A solution of 25.0 g of p-(2-hydroxyethyl)diphenylethylene was added dropwise to F 100, and the mixture was reacted at room temperature. After the reaction was completed, ether extraction was performed, followed by distillation under reduced pressure.
The title compound was obtained. Yield 59A 1H-NMR (CDCj! 3, δ 1 pp
m): 0.2 (s6 H-Si-
Clla), 0.9 (s, 9H-5
i-C'' l moving piece) 2.9 (t, 2H Kayu heat, 3
．． 8 (t, 2H-Honghong-o->, s, 4
(a, 2H,:C=imprint).

7.1-7.3 (2d, 9H phenyl proton) Example 7 -(2-trimethylsiloxyethyl)diphenylethylene t-butyl Dimethylchlorosilane and imidazole were replaced by hexamethyldisilazane, but Example 6
The title compound was obtained in the same manner as above.

Yield 90% 'H-NMR (CDOI!3, δ, ppm)
: 0.1 (s9 H-3i-(C)+3)
3), 2.9 (t, 2H-=□-CH23,
8(t, 2H-Ct12-0), 5.4
(d, 2HnC=CHz7.1-7.3 (2
d, 9H phenyl proton) Example 8 (2-tert-butoxyethyl)diphenylethylene Into a 21 flask equipped with a stirrer, reflux condenser and gas inlet tube, 500 m of methylene chloride, p-(2-hydroxyethyl)diphenylethylene 40 g of concentrated sulfuric acid were added, and 100 g of isobutylene was blown into the flask at 0°C. After the reaction was completed, ether extraction was performed, followed by distillation under reduced pressure to obtain the title compound. Yield 72%'H-NMR (CDCI2z, δ,
pprn): 1.2 (s.

9H-0-C kokutan 1), 3.6 (t, 2H-mark 2-0
- ).

2.9 (t, 2H-@-ken2-), 5.4 (
d, 2H2C=starvation 2), 7.2-7.4 (2d, 9
Example 9 THF8 at -78°C using the break seal method under high vacuum
n-butyllithium (0,282N) 8.0 in 9mJ2
Add 5 mJ2 and further add 1.3 g of p-(2-trimethylsiloxyethyl)diphenylethylene (MODP) to T.
HE30m1. A molten solution was added to the solution, and the mixture was allowed to react for 1 hour. Next, at the same temperature, 1 methyl methacrylate (MMA)
3.3 was added, and after reacting for 1 hour, a small amount of methanol was added to stop the reaction. The number average molecular weight M n (GPC, polystyrene equivalent) and molecular weight distribution M w / M n of the obtained polymer were 3.2 x 10, respectively.
4 and 2.23.

Example 10 THF at -40°C using break seal method under high vacuum
I 41mJ', n-butyllithium (0,282
A solution of 1.4 g of MODP in 6.95 g of THFIO was added and reacted for 1 hour. Then MMAl at -78℃
After 1 hour of reaction, a fresh amount of methanol was added to stop the reaction. The obtained polymer (Mk=5.1
Mn (GPC) M w / M n and Mn (VPO) of
4 and 1.6×104.

Also, from the IH-NMR measurement results and the Mn (VPO) value, the number of MODP units per polymer chain molecule is 1.
．． It became 1.

Example 11 THF15 at -40°C using the polymer break seal method.
0mJ! , n-butyllithium (0,282N) 8.0
p(2-tertbutyldimethylsiloxyethyl)diphenylethylene (BODP) in 0d and THF15d
1.40 g of solution was added and reacted for 1 hour. Next one seven
After 1 hour of reaction at 8°C by adding MMAll and 3 volumes, a small amount of methanol was added to stop the reaction. M n (G P C) of the obtained polymer (Mk=5.1×103)
, M w/M n and Mn (VPO) are 5.3xlO3,1,29 and 4.1x103 respectively
It became. Further, the number of BODP units per molecule of polymer chain determined in the same manner as in Example 10 was 1.3.

Example 12 Using THF at -40°C using break seal method under high vacuum
150mf1. n-butyllithium (0,282N
)7.90d and THF36m! p in e (2tert
A solution of -phthoxyethyl)diphenylethylene (BTDP) was added and reacted for 1 hour. Then MMA at -78℃
After adding OmK' and reacting for 1 hour, a small amount of methanol was added to stop the reaction. The obtained polymer (Mk=
5.0 x 103) Mn CGPC), Mn (
VPO) and M w / M n are 4.9, respectively.
X103, 4.6X103 and 1.21. Further, the number of BTDP units per molecule of polymer chain determined in the same manner as in Example 10 was 1.2.

Example 13 Using the break-seal method under an argon atmosphere, T was
HF33j! , n-butyllithium (1°75N) 18
5-shu and BTDPloog were added, and the mixture was allowed to react for 1 hour. Next, 2.01 MMA was added at -78°C, and after reacting for 1 hour, a large excess of carbon dioxide was added to stop the reaction.

Mn (GPC), Mn (VP
O) and M w /Mn are each 6°4Xl 0
It became 3,7.0X103 and 1.28. In addition, BT per molecule of polymer chain obtained in the same manner as in Example 10
The number of DP units was 1. Further, the functionality of the terminal carboxylic acid determined by alkaline titration and 'rn(VPO) was 0.99. (Carboxylic acid concentration -1,41 x 10-4 mol/g) It was confirmed by IH-NMR that the protecting group was completely eliminated by further adding hydrobromic acid to the acetone solution and refluxing.

Claims (9)

[Claims] (1) In the anionic polymerization of monomers capable of anionic polymerization, the anionic polymerization initiator has the formula (a) ▲ Numerical formula, chemical formula, table, etc. ▼ (I) (In the formula, R_1 is C_1-C_6 alkyl, R_2 is a direct bond, or C_1-C_6 alkylene, R_3 represents a protecting group for the hydroxy group), or an α-alkylstyrene derivative of the formula ▲ Numerical formula, chemical formula, table, etc. ▼ (II) (In the formula, R_2 and R_3 is the same as above, R_3
4 represents hydrogen or C_1-C_6 alkyl. ) with an organometallic compound of the formula MR_5 (wherein M is a metal element of group Ia of the periodic table and R_5 represents C_1-C_6 alkyl or cumyl), or (b) after reacting the compound of formula (I) with the organometallic compound of formula MR_5, the formula ▲ has a mathematical formula, chemical formula, table, etc. ▼ (III) (in the formula, R_4 is the same as above). An anionic polymerization method characterized by using a compound obtained by reacting diphenylethylene or a derivative thereof. (2) The method of item 1, wherein the anionically polymerizable monomer is selected from styrene and its derivatives, diene compounds, (meth)acrylic esters, or (meth)acrylonitrile. (3) The method according to item 1 or 2, wherein the number average molecular weight of the polymer obtained by anionic polymerization is 1,000 to 1,000,000. (4) The method according to any one of Items 1 to 3, which includes the step of deactivating the growing end of the polymer by reacting the growing end with a proton donor. (5) A step of introducing a functional group capable of reacting with a crosslinking agent and simultaneously deactivating the growing terminal by reacting a reagent for introducing a functional group capable of reacting with a crosslinking agent to the growing end of the polymer. The method according to any one of paragraphs 1 to 3, including: (6) After deactivating the growing end of the polymer, protect group R_3
6. The method according to item 4 or 5, comprising the step of regenerating the hydroxyl group by reacting it with a reagent capable of eliminating the hydroxyl group. (7) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) (In the formula, R_2 represents a direct bond or C_1-C_6 alkylene, R_3 represents a protecting group for a hydroxy group, and R_4 represents hydrogen or a C_1-C_6 alkyl group. ) diphenylethylene derivative. (8) R_2 is ethylene, R_3 is tri-C_1-C_6
Diphenylethylene derivative according to item 7, wherein alkylsilyl, R_4 is hydrogen. (9) α-(2-TriC_1-C_6 alkylsiloxyethyl)phenylstyrene.