JP2001026611A - Improved polymerization initiator for vinyl phenol or vinyl phenol derivative and polymerization method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cation polymerization initiator which is excellent in living polymerization of a vinyl phenol or its derivative and which yields a polymer with a narrower molecular weight distribution by using boron trifluoride or a boron trifluoride complex, a specific compound and a specific amount of water. SOLUTION: A compound of the formula is used and the ratio (molar ratio) of water to boron trifluoride or a boron trifluoride complex is 1:(20-500). In the formula, R1 is H or a hydrocarbon; R2 is H, a hydrocarbon, hydroxy or hydrocarbyloxy; and n is 1-3. As the compound of the formula, especially 4- methoxy-α-methylbenzyl alcohol, 4-hydroxy-α-methylbenzyl alcohol and 1- ethoxy-1-(4-methoxyphenyl)ethane are preferable. Usually 0.01-50 mol of the compound of the formula is used per mol of boron trifluoride or a boron trifluoride complex.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an improved polymerization initiator for vinylphenol or a vinylphenol derivative and a polymerization method using the same. More specifically, the present invention provides a polymerization initiator suitable for cationic polymerization of vinyl phenol or a vinyl phenol derivative, which enables the molecular weight distribution to be improved, and vinyl phenol or a vinyl phenol derivative using the polymerization initiator. It relates to a polymerization method.

[0002]

2. Description of the Related Art Polymers obtained from vinyl phenol or vinyl phenol derivatives (hereinafter sometimes abbreviated simply as vinyl phenols) have been used in various industrial fields as functional polymer materials, ie, photosensitive resins, thermosetting resins, and the like. It is used as a conductive resin, a coating material, a raw material for a rust inhibitor and the like. or,
In recent years, vinylphenol polymers have been used in the field of electronic materials,
In particular, it has attracted attention as an indispensable material for a photoresist for manufacturing a highly integrated semiconductor circuit. Vinylphenol polymers must have a molecular weight and molecular weight distribution suitable for such various uses, and strict control of the molecular structure, including copolymerization with other vinyl monomers, is required. is needed.

[0003] As a polymerization method for vinylphenols, a radical polymerization method or a cationic polymerization method is generally known. In particular, in the case of the cationic polymerization method, polymerization in which the active terminal of the growing molecule does not undergo a termination reaction or a chain transfer reaction,
If so-called "living polymerization" is realized, not only strict control of molecular weight and molecular weight distribution, but also control of polymer terminals will be possible. Therefore, for example, by adding another cationic polymerizable monomer to the living polymerization terminal of a specific monomer and polymerizing it, or by synthesizing a block copolymer, or by reacting a terminator having a vinyl group in the molecule, a macromonomer Can be synthesized, and the range of molecular design of the polymer can be greatly expanded.

[0004] However, regarding the cationic polymerization method of vinylphenols, there is no literature that describes an initiator exhibiting living polymerizability. For example, JP-A-51-39788 proposes a method of polymerizing parahydroxystyrene (that is, p-vinylphenol) using a cationic polymerization initiator such as a boron trifluoride complex in the presence of a nitrile compound. Have been. However, this publication does not mention the living polymerizability of the initiator. Also, the weight average molecular weight (M) measured by gel permeation chromatography (GPC method)
w) and the number average molecular weight (Mn) ratio Mw / Mn is 2.8 to
The molecular weight distribution of the resulting polymer is relatively broad.

Accordingly, the inventors of the present invention have previously proposed a novel initiator suitable for the cationic polymerization of vinylphenol or vinylphenol derivatives by using boron trifluoride or a mixture comprising boron trifluoride complex and water. An initiator combining specific organic compounds has been proposed (Japanese Patent Application No. 11-1260).
No. 43). This initiator is excellent in living polymerizability and has a molecular weight distribution (Mw / Mn) of the obtained polymer of 1.
It was relatively narrow, 70 to 2.20. However, in recent years, with higher performance in various uses of vinylphenols, a polymer having a narrower molecular weight distribution has been demanded.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a polymerization initiator for vinylphenol or a vinylphenol derivative, which can provide a polymer having excellent living polymerizability and a narrower molecular weight distribution. It is to provide an initiator for cationic polymerization.

Another object of the present invention is to provide a method for polymerizing vinyl phenol or a vinyl phenol derivative using the initiator for cationic polymerization.

[0008]

SUMMARY OF THE INVENTION In view of the above-mentioned situation, the inventors of the present invention have previously described Japanese Patent Application No. 11-126043.
As a result of further research on the initiator for cationic polymerization of vinylphenol or vinylphenol derivative proposed in the above item, it was found that a polymer having a very narrow molecular weight distribution can be obtained by selecting the ratio of the initiator components, and the present invention was completed. Was.

That is, the gist of the first invention in the present application is:
(A) boron trifluoride or boron trifluoride complex, (B)
General formula (1)

Embedded image (Wherein, R ¹ represents a hydrogen atom or a hydrocarbon group, R ² represents a hydrogen atom, a hydrocarbon group, a hydroxy group or a hydrocarbyloxy group, and n represents an integer of 1 to 3, respectively.
When n is 2 or more, R ² may be the same or different. ) And (C) water;
The ratio (molar ratio) of the component (C) to the component (A) is 1:
A polymerization initiator for vinylphenol or vinylphenol derivative characterized by being 20 to 500,
Further, the gist of the second invention is to provide a method for polymerizing vinylphenol or a vinylphenol derivative in an organic solvent, wherein (A) boron trifluoride or a boron trifluoride complex,
(B) General formula (1)

Embedded image (In the formula, R ¹ represents a hydrogen atom or a hydrocarbon group, R ² represents a hydrogen atom, a hydrocarbon group, a hydroxy group or a hydrocarbyloxy group, and n represents an integer of 1 to 3, respectively.
When n is 2 or more, R ² may be the same or different. ) And (C) water;
The ratio (molar ratio) of the component (C) to the component (A) is 1:
The present invention resides in a polymerization method using a polymerization initiator of 20 to 500.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The first component constituting the polymerization initiator of the present invention is boron trifluoride or a boron trifluoride complex.
As the boron trifluoride complex, especially diethyl ether,
Complexes with ethers such as dipropyl ether and dibutyl ether, or complexes with methanol, phenol, water and the like are preferred.

The second component constituting the polymerization initiator of the present invention is a compound represented by the above general formula (1).
In the formula (1), R ¹ represents a hydrogen atom or a hydrocarbon group, and when R ¹ is a hydrocarbon group, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 16 carbon atoms, Number 7-1
8 arylalkyl groups or alkaryl groups.

In the above formula (1), R ² is a hydrogen atom,
Hydrocarbon group, a hydroxy group or a hydrocarbyloxy group, if R ² is a hydrocarbon radical, in particular the R ¹
And when R ² is a hydrocarbyloxy group, an alkoxy group having 1 to 10 carbon atoms and an alkoxy group having 6 to 1 carbon atoms
6 represents an aryloxy group, an arylalkoxy group having 7 to 18 carbon atoms, or an alkaryloxy group. When n is 2 or 3, that is, when R ² is bonded to a plurality of benzene nuclei, these groups may be the same or different.

Specific examples of the compound represented by the general formula (1) include 4-methoxy-α-methylbenzyl alcohol, 4-ethoxy-α-methylbenzyl alcohol,
4-phenoxy-α-methylbenzyl alcohol, 4-
(4-methylphenoxy) -α-methylbenzyl alcohol, 4-hydroxy-α-methylbenzyl alcohol, 1-ethoxy-1- (4-methoxyphenyl) ethane, 1-phenoxy-1- (4-methoxyphenyl) ethane 1- (4-ethylphenoxy) -1- (4-methoxyphenyl) ethane, 3-methoxy-α-methylbenzyl alcohol, 3-ethoxy-α-methylbenzyl alcohol, 3-phenoxy-α-methylbenzyl alcohol, 3-hydroxy-α-methylbenzyl alcohol, 1-ethoxy-1- (3-methoxyphenyl) ethane, 1-ethoxy-1- (3-phenoxyphenyl) ethane, 4-hydroxy-3-methyl-α-methylbenzyl Alcohol, 3-t-butyl-4-hydroxy-α-
Methylbenzyl alcohol, 4-hydroxy-3-methoxy-α-methylbenzyl alcohol, 3-hydroxy-4-methoxy-α-methylbenzyl alcohol, 4-
t-butoxy-3-hydroxy-α-methylbenzyl alcohol, 3,4-dihydroxy-α-methylbenzyl alcohol, 1-ethoxy-1- (4-hydroxy-3
-Methylphenyl) ethane, 1-ethoxy-1- (4-
Hydroxy-3-methoxyphenyl) ethane, 1-ethoxy-1- (4-t-butoxy-3-hydroxyphenyl) ethane, 1-ethoxy-1- (3,4-dihydroxyphenyl) ethane, and the like. 4-methoxy-
α-methylbenzyl alcohol, 4-hydroxy-α-
Methylbenzyl alcohol and 1-ethoxy-1- (4
-Methoxyphenyl) ethane is preferred.

Many of the compounds represented by the above general formula (1) can be easily prepared. For example, 4-hydroxy-α-methylbenzyl alcohol is obtained by reducing commercially available 4-hydroxyacetophenone. Also, 4-methoxy-α-methylbenzyl alcohol can be produced by reducing commercially available 4-methoxyacetophenone. Further, 1-ethoxy-1- (4
-Methoxyphenyl) ethane is 4-methoxy-α-
It can be produced by etherifying methylbenzyl alcohol with ethanol.

Further, the third component constituting the polymerization initiator of the present invention is water.

The ratio of the components constituting the polymerization initiator of the present invention is such that the compound represented by the general formula (1) is 0.1 to 1 mol of boron trifluoride or boron trifluoride complex.
The amount is from 01 to 50 mol, preferably from 0.02 to 20 mol. Water is 20 to 500 mol, preferably 30 to 30 mol, per mol of boron trifluoride or boron trifluoride complex as a total amount including water in all raw material components.
0 mol.

When the required amount of water is relatively small depending on the polymerization conditions, for example, the water originally contained in each of the above-mentioned components constituting the polymerization initiator may be sufficient and may not require additional addition. . However, if the amount of water in the polymerization system fluctuates for each polymerization, the polymerization rate, molecular weight, etc. will be affected, so the water content in the raw material components can be accurately grasped by a water analysis method such as the Karl Fischer method. However, it is preferable to confirm that the total amount of all the raw materials including water is within the above range.

In the present invention, the monomer used for polymerization with the polymerization initiator constituted as described above is a vinyl phenol, that is, vinyl phenol or a vinyl phenol derivative. Specific examples of vinyl phenol include p-vinyl phenol and m-vinyl phenol, and p-vinyl phenol is particularly preferred.

Examples of the vinylphenol derivative include p-alkoxystyrene and m-alkoxystyrene in which phenolic hydrogen of vinylphenol is substituted with an alkyl group, and p-alkoxystyrene is particularly preferred. Specific examples include p-methoxystyrene, p-ethoxystyrene, pt-butoxystyrene, m-methoxystyrene, m-ethoxystyrene, mt-butoxystyrene and the like, particularly p-methoxystyrene, p-ethoxystyrene and the like. Styrene and pt-butoxystyrene are preferred.

Further, as the vinylphenol derivative,
Examples thereof include p-acetoxystyrene or m-acetoxystyrene in which phenolic hydrogen of vinylphenol is substituted with an acetyl group, and p-acetoxystyrene is particularly preferred.

The above-mentioned vinyl phenol can be synthesized by a conventionally known method such as hydrolysis of acetoxystyrene, decarboxylation of hydroxycinnamic acid, catalytic decomposition of bisphenolethane, and dehydrogenation of ethylphenol. Specifically, "Vinylphenol-Basics and Applications"
(1991, published by the Educational Publishing Center) The method described on page 22 or below, or the cited reference may be referred to.

The p-alkoxystyrene or m-alkoxystyrene of the above vinylphenol derivatives is obtained by reacting, for example, p-vinylphenol or m-vinylphenol with an alkyl halide in the presence of a basic compound such as pyridine. Can be obtained.

Further, p-acetoxystyrene or m-acetoxystyrene among the above-mentioned vinylphenol derivatives is obtained, for example, by reacting p-vinylphenol or m-vinylphenol with acetic anhydride in the presence of a basic compound such as pyridine. Can be obtained by:

On the other hand, in the polymerization method of the present invention, the above-mentioned vinyl phenols are polymerized by using the above-mentioned polymerization initiator. The amount of boron trifluoride or boron trifluoride complex in the polymerization initiator is 0.0
The amount is a ratio of 01 to 1, preferably 0.002 to 0.6.

The polymerization method of the present invention is carried out in an organic solvent. Examples of the organic solvent include aromatic hydrocarbons such as benzene, toluene and ethylphenol;
Halogenated hydrocarbons such as dichloromethane and carbon tetrachloride;
Nitrile compounds such as acetonitrile and propionitrile are used. Among these solvents, nitrile compounds, which are particularly excellent in the solubility of many vinylphenol polymers and have a low boiling point and are easily removed from the vinylphenol polymers, are preferable.

The conditions of the polymerization method of the present invention are as follows: the temperature is -70 to 100 ° C, preferably -30 to 80 ° C;
The time is 1 minute to 30 hours, preferably 5 minutes to 10 hours. In addition, the polymerization initiator of the present invention gives a high molecular weight substance even at a high polymerization temperature of cationic polymerization of room temperature or higher.

The concentration of vinylphenols in the polymerization system is generally 10 to 80% by weight, preferably 20 to 7% by weight.
0% by weight, and at a high concentration exceeding 80% by weight, it may be difficult to control the reaction temperature due to heat of polymerization,
In addition, since the reaction solution has a high viscosity due to the produced polymer, the polymerization rate cannot be increased to a certain level or more, and the productivity is deteriorated. On the other hand, at low concentrations below 10% by weight,
The use amount of the organic solvent increases, which may be disadvantageous in practical use.

The molecular weight of the polymer can be controlled by several conditions such as the polymerization time, the monomer concentration in the polymerization system, the initiator concentration, and the ratio of the components of the initiator. Adjusting the concentration or the component ratio of the initiator is convenient and convenient from a practical viewpoint.

As described above, the vinylphenol polymer, which is a product obtained by the polymerization method of the present invention, is obtained by a lower alcohol solution containing a lower alcohol such as methanol, and optionally a basic compound such as ammonia or an amine. Termination of the polymerization, that is, deactivation of the growth terminal is performed. Then, the product as it is, or after washing with water, methanol, etc.,
By removing unreacted monomers and solvent by a solvent reprecipitation method or a thin film evaporation method, a target vinylphenol polymer can be obtained.

In the present invention, when the polymerization conditions in the following examples are adopted, the molecular weight (number average molecular weight) is usually 3,
A polymer having a molecular weight distribution (Mw / Mn) of 2,000 to 20,000 and a molecular weight distribution (Mw / Mn) of 1.20 to 1.50 is obtained.

[0032]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

In the following examples, the polymerization rate (ie, the conversion rate of the monomer) was determined by measuring the residual monomer in the polymerization solution by ¹ HN
It was determined by analysis by MR. The weight average molecular weight Mw and the number average molecular weight Mn of the polymer were determined by gel permeation chromatography (solvent: DMF, temperature: 40 ° C.).
Was measured by Further, the ratio between Mw and Mn was calculated and used as an index of the molecular weight distribution. Each experiment in this example was performed under conditions where the monomer concentration and the like were relatively low in order to increase the accuracy of the polymerization experiment and analysis.

Example 1 A dry glass reactor was replaced with nitrogen gas. 2.62 ml of acetonitrile was charged as a solvent into this reaction vessel, followed by 0.073 g of p-vinylphenol (0.
6 mmol), 10.8 μl (0.6 mmol) of water and 1.68 of 4-methoxy-α-methylbenzyl alcohol.
μl (0.012 mmol) were added sequentially. The temperature of the system was adjusted to 0 ° C. while stirring the mixed solution, and then a solution of boron trifluoride diethyl ether complex in acetonitrile was added.
3 ml (0.006 mmol as boron trifluoride diethyl ether complex) was added to initiate polymerization. With the passage of time, the polymerization was continued until 3 hours later while taking the polymerization solution as a sample from the system. Each sample was subjected to ¹ H NMR analysis and GPC measurement after the polymerization reaction was terminated with ammoniacal methanol and post-treated.

The conversion, Mw, Mn, and M for each sample
w / Mn is shown in Table 1. FIG. 1 is a graph showing the relationship between the conversion rate data and the Mn data in Table 1. As is clear from FIG. 1, the Mn of the obtained polymer increases linearly with the conversion, and the catalyst of this example shows living polymerizability. This catalyst has a very narrow molecular weight distribution of Mw / Mn of 1.27 at a conversion of 99%.

[0036]

[Table 1]

Example 2 [Polymerization experiment (1) to (3)] A polymerization experiment (1) was performed in the same manner as in Example 1 except that the polymerization temperature and the polymerization time were changed as shown in Table 2. ) To (3) and further post-processing. Table 2 summarizes the results.

[0038]

[Table 2]

Example 3 In Example 1, the amount of p-vinylphenol used was changed to 2
Polymerization was carried out in the same manner as in Example 1 except that the amount was doubled.
Samples were collected and post-treated in the same manner as in Example 1 for up to 2 hours, and then these samples were subjected to ¹ H NMR analysis and GPC measurement. The results were as shown in Table 3.

[0040]

[Table 3]

Example 4 In Example 1, p-vinylphenol was replaced with p-vinylphenol.
Polymerization was carried out in the same manner as in Example 1 except that the same molar amount of -methoxystyrene was used. Samples were collected and post-treated in the same manner as in Example 1 for up to 14 hours, and then these samples were subjected to ¹ H NMR analysis and GPC measurement. The results were as shown in Table 4.

[0042]

[Table 4]

Example 5 (Block copolymerization) Under the same conditions as in Example 1, first, p-
Vinyl phenol was polymerized for 2 hours. At this time, the conversion of the monomer was 95%. A part of the reaction solution was collected, and after the post-treatment, ¹ HNMR analysis and GPC measurement were performed. As a result, Mn was 5,430 and Mw / Mn was 1.27. Met. Next, as the second stage polymerization, p-methoxystyrene was added to the reaction vessel in an equimolar amount with p-vinylphenol, and the polymerization was continued for another 24 hours. The reaction product was post-treated in the same manner as in Example 1 and subjected to ¹ H NMR analysis and GPC measurement. As a result, Mn was 15,180, and Mw / Mn was 1.
72. The molecular weight distribution by GPC showed two peaks.

The produced polymer was slightly aggregated, and a reaction between polymer chains due to poor solubility in acetonitrile was expected. Therefore, this polymer was dissolved in dimethylformamide, 4N hydrochloric acid was added, and heat treatment was performed at 60 ° C. for 2 hours. The polymer after the treatment had Mn of 11,030, Mw / Mn of 1.34, and GP
The molecular weight distribution by C showed one peak. Mn is 1
From the fact that the molecular weight was 1,030, which is about twice the molecular weight of the first stage, and the peak of the molecular weight distribution is also one, it is highly likely that the crosslinked product was mixed into the polymerization product of the second stage. Incidentally, the final conversion rate of the monomer was 1 for p-vinylphenol.
At 00%, p-methoxystyrene was 96%.

[0045]

Industrial Applicability The polymerization initiator of the present invention for vinylphenol or vinylphenol derivatives is excellent in living polymerizability. When this initiator is used for the cationic polymerization of vinylphenol or vinylphenol derivatives, it has an extremely narrow molecular weight. A distribution of polymers can be obtained. Also, since it has excellent living polymerizability, it can be applied to the production of blog copolymers and macromonomers.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the conversion rate data and the Mn data of the polymer obtained in Example 1.

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Claims (5)

[Claims] (A) boron trifluoride or a boron trifluoride complex, (B) a general formula (1) (Wherein, R ¹ represents a hydrogen atom or a hydrocarbon group, R ² represents a hydrogen atom, a hydrocarbon group, a hydroxy group or a hydrocarbyloxy group, and n represents an integer of 1 to 3, respectively.
When n is 2 or more, R ² may be the same or different. ) And (C) water;
The ratio (molar ratio) of the component (C) to the component (A) is 1:
An initiator for polymerization of vinylphenol or a vinylphenol derivative, which is 20 to 500. 2. A compound represented by the general formula (1):
The methoxy-α-methylbenzyl alcohol, 4-hydroxy-α-methylbenzyl alcohol or 1-ethoxy-1- (4-methoxyphenyl) ethane.
3. The polymerization initiator according to item 1. 3. A method for polymerizing vinyl phenol or a vinyl phenol derivative in an organic solvent, comprising: (A) boron trifluoride or a boron trifluoride complex; and (B) a general formula (1). (Wherein, R ¹ represents a hydrogen atom or a hydrocarbon group, R ² represents a hydrogen atom, a hydrocarbon group, a hydroxy group or a hydrocarbyloxy group, and n represents an integer of 1 to 3, respectively.
When n is 2 or more, R ² may be the same or different. ) And (C) water;
The ratio (molar ratio) of the component (C) to the component (A) is 1:
A polymerization method using a polymerization initiator having a molecular weight of 20 to 500. 4. The method according to claim 3, wherein the vinylphenol or vinylphenol derivative is p-vinylphenol, p-alkoxystyrene or p-acetoxystyrene. 5. A compound represented by the general formula (1):
4. It is methoxy-α-methylbenzyl alcohol, 4-hydroxy-α-methylbenzyl alcohol or 1-ethoxy-1- (4-methoxyphenyl) ethane.
The polymerization method described in 1.