JPH0453807A - Production of p-alkenylphenol polymer - Google Patents

Abstract

PURPOSE:To narrow mol.wt. distribution and improve thermal stability and compatibility by randomly copolymerizing a conjugated diene and/or a vinylarom. compd. and a specific compd. in the presence of an org. alkali metal compd. and removing a protective aliph. satd. group from the resulting copolymer. CONSTITUTION:A 4-12C conjugated diene and/or a vinylarom. compd. and a compd. of the formula (wherein R1 is H or methyl; and R2 is 1-4C alkyl) wherein a phenolic hydroxyl group is protected by an aliph. satd. group. are randomly copolymerized by anionic polymn. in the presence of a polymn. initiator comprising an org. alkali metal compd. (e.g. ethyllithium) in an inert gas atmosphere in an org. solvent at -100 to 150 deg.C. Then, at least one compd. selected from the group consisting of hydrochloric acid, hydrogen chloride gas, and 1,1,1- trifluoroacetic acid is added to the polymn. system and allowed to react to remove the protective group from the resulting copolymer.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a method for producing a p-alkenylphenol copolymer, and more specifically, the present invention relates to a method for producing a p-alkenylphenol copolymer, and more specifically, a method for producing a p-alkenylphenol copolymer, and more specifically, a method for producing a p-alkenylphenol copolymer. The present invention relates to a method for producing a p-alkenylphenol copolymer obtained by anionic polymerization of a compound whose hydroxyl group is protected with a saturated aliphatic protecting group using an organic alkali metal compound as a polymerization initiator.

[Conventional technology]

Polymers of p-alkenylphenol, typified by p-vinylphenol, have been known to be useful as resist materials, curing agents for epoxy resins, antioxidants, and the like.

As a method for producing p-alkenylphenol polymer,
Crude p- containing large amounts of phenol, cresol, etc. is produced by dehydrogenation of p-ethylphenol, thermal decomposition of bisphenol ethane, decarboxylation of p-hydroxycinnamic acid, etc.
After obtaining vinylphenol, a p-vinylphenol polymer is obtained by thermal polymerization or radical polymerization (JP-A-53-13694, JP-A-57-44607, JP-A-57-44608) , Japanese Patent Publication No. 57-4
(See Publication No. 4609, Special Publication No. 61-2683, etc.)
After polymerizing a monomer in which the hydroxyl group of p-vinylphenol is protected by tert-butyldimethylsilane using an anionic polymerization initiator consisting of an organometallic compound such as n-butyllithium or sodium naphthalene, the monomer is treated with an acidic reagent. A method for obtaining p-vinylphenol polymers with narrow molecular weight distribution by
, 45.1986) have been proposed.

[Problem that the invention seeks to solve]

In recent years, p-alkenylphenol polymers with controlled structures containing phenolic hydroxyl groups have been used as resist materials with submicron resolution required for the production of VLSIs, as well as as separation membranes and biocompatible polymer materials. Copolymers with various other monomers are attracting attention.

However, p-alkenylphenol homopolymers, which are p-alkenylphenol-based polymers, still have problems in terms of solubility in solvents and compatibility with other resins, and it is difficult to improve these properties. Therefore, copolymers with various other monomers are desired.

In the above-mentioned production method, p-vinylphenol obtained from crude p-vinylphenol by thermal polymerization method or radical polymerization method is used.
Vinylphenol polymer has an extremely wide molecular weight distribution.
Furthermore, it has the disadvantage that it is difficult to obtain a polymer with a controlled structure. Furthermore, there are problems in that the resulting polymer is easily colored and it is extremely difficult to remove trace amounts of impurities.

The method of anionic polymerization by protecting the hydroxyl group of p-vinylphenol with tert-butyldimethylsilane is not industrially advantageous because the tert-butyldimethylsilyl chloride used for silylation is extremely expensive.

Therefore, an object of the present invention is to provide an industrially advantageous manufacturing method for producing a p-alkenylphenol copolymer having a narrow molecular weight distribution and a controlled structure.

[Means for solving problems]

As a result of intensive research to achieve the above object, the present inventors have discovered that a compound in which the phenolic hydroxyl group of p-alkenylphenol is protected with a saturated aliphatic protecting group and a conjugated diene and/or a vinyl aromatic compound are combined into organic After random copolymerization using an alkali metal compound as a polymerization initiator, the saturated aliphatic protecting group is removed to obtain a p-alkenylphenol copolymer, resulting in a narrow molecular weight distribution and controllable structure. The present invention was completed by discovering that p-alkenylphenol copolymers can be produced easily and inexpensively.

That is, the present invention produces a conjugated diene and/or by an anionic polymerization method using an organic alkali metal compound as a polymerization initiator
Alternatively, a vinyl aromatic compound and a compound in which the hydroxyl group of a phenol residue represented by the following general formula (I) represents an alkyl group having 1 to 6 carbon atoms is protected with a saturated aliphatic protecting group are randomly combined. This is a method for producing a p-alkenylphenol copolymer, which is characterized in that after polymerization, a saturated aliphatic protecting group is removed.

The present invention will be explained in detail below.

The conjugated diene used in the present invention has 4 to 1 carbon atoms.
The conjugated diene of No. 2 is - -, for example, 1,3-butadiene, isoprene, 2,3-methyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1, Examples include 3-hexadiene, 4,5-diethyl-1,3-octane, and 3-butyl-1,3-octane, and these may be used alone or in a mixture of two or more.

Examples of vinyl aromatic compounds include styrene, O-methylstyrene, p-methylstyrene, α-methylstyrene, and p-methylstyrene.
-tert-butylstyrene, 1,3-butylstyrene, vinylnaphthalene, divinylbenzene, 1,1-diphenylethylene, etc., and these may be used alone or in a mixture of two or more.

Examples of the p-alkenylphenol compound represented by the general formula (I) include p-n-butoxystyrene, p-5e
Examples include c-butoxystyrene, p-tert-butoxystyrene, p-tert-butoxy-α-methylstyrene, and p-tert-butoxystyrene and p-tert-butoxy-α-methylstyrene are particularly preferred. .

In the method for producing the copolymer of the present invention, the reaction is carried out by an anionic polymerization method using the above-mentioned conjugated diene, vinyl aromatic compound, and p-alkenylphenol compound, and an organic alkali metal compound as a polymerization initiator. The reaction is carried out in an organic solvent at a temperature of -100 to 150°C under an inert gas atmosphere such as nitrogen or argon.

After the reaction is completed, other vinyl monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, etc. are added to the reaction system.
meth)acrylic esters: 2-vinylpyridine, 4-
It is also possible to react by adding one or more of vinylpyridines such as vinylpyridine and acrylonitrile.

As the polymerization initiator for the organic alkali metal compound used in the copolymerization reaction, alkyl, allyl, and aryl compounds of alkali metals such as lithium and sodium are used. Examples of these compounds include ethyllithium, n-butyllithium, 5eC-butyllithium, t
ert-butyl lithium, ethyl sodium, butadienyl dilithium, butadienyl sinatrim, lithium biphenyl, lithium naphthalene, lithium triphenyl, lithium fluorene, sodium biphenyl, sodium naphthalene, sodium triphenyl, sodium fluorene, α-methylstyrene sodium silicate Examples include anions, and these may be used alone or in a mixture of two or more.

In addition, as organic solvents, aliphatic hydrocarbons such as n-hexane and n-hebuta; alicyclic hydrocarbons such as cyclohexane and cyclopenkune; aromatic hydrocarbons such as benzene and toluene; diethyl ether, dioxane, It is used as one or a mixed solvent of two or more organic solvents commonly used in anionic polymerization, such as ethers such as tetrahydrofuran.

In the above copolymerization reaction, when introducing a functional group to the end of the copolymer chain, after the reaction is completed, the reaction solution is treated with carbon dioxide or a cyclic ether compound such as ethylene oxide, and then treated with water, hydrochloric acid, methanol, etc. By treatment with , carboxyl groups and hydroxyl groups are introduced, respectively.

A saturated aliphatic protecting group is removed from a random copolymer consisting of the conjugated diene unit and/or vinyl aromatic compound unit and the compound unit represented by the general formula (1) to generate a p-alkenylphenol skeleton. The reaction is carried out using hydrochloric acid, hydrogen chloride gas, hydrobromic acid, 1,
It can be carried out at a temperature of room temperature to 150°C, preferably room temperature to 100°C, with the addition of at least one type such as 1.1-trifluoroacetic acid. In this reaction, side reactions such as polymer chain cutting and intermolecular crosslinking hardly occur, and the molecular weight and molecular weight distribution before and after the reaction hardly change.

The p-alkenylphenol copolymer obtained by the production method of the present invention has a narrow molecular weight distribution, has a highly reactive phenolic hydroxyl group in the molecule, and has excellent thermal stability.
Furthermore, due to its excellent compatibility with various resins, it is expected to be used in a wide range of fields as a modifier for photosensitive resins, chelate resins, polymer electrolytes, antioxidants, and thermosetting and thermoplastic resins. .

〔Example〕

The present invention will be explained in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited in any way by these Examples.

In addition, in the examples, "parts" and "%" are based on weight unless otherwise specified.

Example 1 In a nitrogen atmosphere, 10 mmol of n-butyllithium was added to tetrahydrofuran (THF, hereinafter abbreviated as THF).
0.034 mol of p-tert-butoxystyrene (trade name: Hokuko PTBST, Hokuko Chemical Co., Ltd., hereinafter abbreviated as PTBST) and 1.3-mol of p-tert-butoxystyrene (trade name: Hokuko PTBST, hereinafter abbreviated as PTBST) were added to 100 g of a solution under stirring and maintained at -40°C. 150 g of THF solution containing 0.444 mol of butadiene (pre-cooled to -40°C)
was added dropwise over 3 hours, and the reaction was continued for an additional 2 hours.

Then, the temperature of the reaction system was lowered to -60°C, 30 mmol of ethylene oxide was added, water was added to stop the reaction, and the solvent was distilled off under reduced pressure to obtain a pale yellow transparent liquid polymer. . The polymerization yield was 99.0%, and the obtained polymer had a number average molecular weight (section) measured by the V2O method.
3180, the hydroxyl value was 16.7, which was in good agreement with the expected value, and the GPC elution curve showed a single peak, and the weight average molecular weight (node)/number average molecular weight (goods) was 1.05. Furthermore, it was confirmed from the measurement results of 'HNMH (see Figure 1) that polymerization was carried out as expected and that a random copolymer of PTBST and butadiene was obtained.

Next, 10 g of the obtained random copolymer of PTBST and butadiene was dissolved in dioxane to make a 10% solution.
After adding concentrated hydrochloric acid and reacting at 609C for 2 hours, the solvent was distilled off under reduced pressure to obtain 9.2 g of pale yellow transparent liquid polymer.
I got it.

Regarding the random copolymer polymer of PTBST and butadiene used in this reaction and the polymer produced using the random copolymer, '1 (VR was measured and compared, and the tert-butyl group in the former was The peak at 1.3 ppm originating from the origin disappeared in the latter. Furthermore, the produced polymer was in good agreement with the expected value at Mn 2950, and the GPC elution curve showed a unimodal peak. It was a monodisperse polymer with a weight of 1.05.

From the above results, the debutylation reaction from the random copolymer of PTBST and butadiene does not cause any side reactions (progresses as expected, and the desired random copolymerization of p-vinylphenol and butadiene occurs). It was confirmed that a polymer was obtained.

Example 2 Under nitrogen atmosphere, 5ec-butyllithium 3.7
100 g of solution in THF containing mmol - 40 g under stirring
A THF solution containing 0.085 mol of PTBST O and 0.144 mol of styrene was heated at
150 g of the solution was added dropwise over 3 hours, and the reaction was continued for an additional 2 hours, and then methanol was added to stop the reaction.

Next, the reaction solution was poured into a large amount of methanol to precipitate a polymer, which was filtered and washed, and then dried under reduced pressure at 60°C for 5 hours to obtain a white powdery polymer. Polymerization yield is 9
The obtained polymer had a value of 4.8050, which was in good agreement with the expected value, and the GPC elution curve showed a single peak, and the Mw/Mn was 1.07. Further, as in Example 1, it was confirmed from the INMR measurement results that polymerization was carried out as expected and a random copolymer of PTBST and styrene was obtained.

Next, 10 g of the obtained random copolymer of PTBST and styrene was dissolved in dioxane to prepare an IOX solution.
After reacting at room temperature for 15 minutes while blowing hydrogen chloride gas, the reaction solution was poured into a large amount of n-hexane to precipitate the polymer, filtered and washed, and then dried under reduced pressure at 60°C for 5 hours. 8.4 g of a white powdery polymer was obtained.

When we measured and compared the 'HNMR of the random copolymer of PTBST and styrene used in this reaction and the polymer produced using the random copolymer, we found that the terj-butyl group in the former was removed. In addition, as a result of comparing the infrared absorption spectra, it was confirmed that the tert-butyl group in the former
The absorptions at ' and 1360 cm-' disappeared in the latter, and a new broad absorption derived from hydroxyl groups was observed around 3300 cm-'. In addition, the produced polymer is
4.6700, which was in good agreement with the expected value, and the GPC elution curve showed a unimodal peak, and Mw/Mn・1.08
It was a monodisperse polymer.

From the above results, the debutylation reaction from the random copolymer of PTBST and styrene proceeded as expected without any side reactions, and the desired random copolymer of p-vinylphenol and styrene was produced. It was confirmed that a combination was obtained.

Example 3 Under a nitrogen atmosphere, 100 g of a solution in THF containing 7.3 mmol of n-butyllithium was stirred and maintained at 60° C. while adding 0.34 mol of PTBST O and 0.03 mmol of styrene.
．． 150 g of a THF solution containing 0.057 mol and 0.333 mol of 1,3-butadiene (previously cooled to -40°C)
The mixture was added dropwise over time and the reaction was continued for an additional 2 hours.

Then, after adding carbon dioxide to the reaction solution, a hydrochloric acid-methanol solution was added to stop the reaction, and the solvent was distilled off under reduced pressure to obtain a pale yellow transparent liquid polymer. The polymerization yield was 99.
3%, the obtained polymer had an acid value of 4100 and an acid value of 1.
3.3, which is in good agreement with the expected value, and the GPC elution curve shows a monomodal peak, with Mw/Mn=1.05. Furthermore, as in Example 1, the 'HNMR measurement results indicate that polymerization has occurred. It was confirmed that the process was carried out as expected, and a random copolymer of PTBST, styrene, and butadiene was obtained.

Next, 10 g of the obtained random copolymer of PTBST, styrene, and butadiene was dissolved in dioxane, and 10
% solution, added concentrated hydrochloric acid and reacted at 60° C. for 2 hours, and then the solvent was distilled off under reduced pressure to obtain 8.6 g of a pale yellow transparent liquid polymer.

When we measured and compared the 'HNMR and infrared absorption spectra of the random copolymer polymer of PTBST, styrene, and butadiene used in this reaction and the polymer produced using the random copolymer, we found that the former It was confirmed that the tert-butyl group in was eliminated and a hydroxyl group was generated.

Furthermore, the produced polymer had a width of 3500, which was in good agreement with the expected value, and the GPC elution curve showed a single peak, and it was a monodispersed polymer with Mw/Mn of 1.05.

From the above results, the debutylation reaction from the random copolymer of PTBST, styrene, and butadiene proceeds without any side reactions, and the desired random copolymerization of p-vinylphenol, styrene, and butadiene is carried out. It was confirmed that the combination was obtained.

〔Effect of the invention〕

As shown in the above examples, the method of the present invention can easily produce a random copolymer of a conjugated diene and/or vinyl aromatic compound and p-alkenylphenol with a controlled molecular weight and structure and a narrow molecular weight distribution. can be manufactured.

The present invention includes a photosensitive resin, a chelate resin, a polymer electrolyte,
This invention relates to a method for producing p-alkenylphenol copolymers with a controlled structure, which are extremely useful as antioxidants and modifiers for various thermosetting resins and thermoplastic resins, and are industrially advantageous. Yes, and its industrial significance is extremely large.

CH, -CH- CH.

(PTBST unit) HenoVC-C-C-CH3

[Brief explanation of drawings]

FIG. 1 is a diagram showing the 'HNMR absorption spectrum of the copolymer of PTBTS and butadiene obtained in Example 1. Each absorption peak ai in the figure corresponds to hydrogen in the following structural unit. In addition, the shaded part (Δg) of signal g in the figure is PTBS
The butadiene side chain vinyl proton next to PTBST is shifted by a high magnetic field due to the ring current of the aromatic ring of T, and when this signal intensity is compared with the signal intensity of signal i, it is the same intensity, so in the copolymer. BTB
It is presumed that butadiene units are always present on both sides of the ST unit. These results confirmed that the polymerization resulted in a random copolymer of PTBST and butadiene.

Claims (1)

[Claims] (1) Using an anionic polymerization method using an organic alkali metal compound as a polymerization initiator, a conjugated diene and/or vinyl aromatic compound is produced with the following general formula (I) ▲Mathematical formula, chemical formula, table, etc.▼‥‥(I) (Here, R_1 is a hydrogen atom or a methyl group, and R_2 is an alkyl group having 1 to 6 carbon atoms.) The hydroxyl group of the phenol residue represented by R_1 is a hydrogen atom or a methyl group, and R_2 is an alkyl group having 1 to 6 carbon atoms. 1. A method for producing a p-alkenylphenol copolymer, which comprises removing a saturated aliphatic protecting group after polymerization.