JP5521165B2 - Hydroxystyrene dimer derivative, method for producing the same, chain transfer agent, and method for polymerizing radical polymerizable monomer - Google Patents

Description

  The present invention relates to a novel hydroxystyrene dimer derivative useful as a chain transfer agent for obtaining a low molecular weight polymer, a simple production method for obtaining a hydroxystyrene dimer derivative from a hydroxycinnamic acid derivative, and a hydroxystyrene dimer derivative. The present invention relates to a method for polymerizing radically polymerizable monomers.

Polymers obtained by radical polymerization are used for various applications as so-called synthetic resin raw materials. The properties of the polymer can be changed greatly depending on the type of monomer used and copolymerization with different monomers, but it is extremely important to adjust the molecular weight of the polymer in order to obtain the properties and physical properties according to the intended application. Technology.
Addition of a chain transfer agent to a polymerization system is known as one of effective methods as a molecular weight adjustment technique in radical polymerization reaction. Many known compounds have been proposed as chain transfer agents, and α-methylstyrene dimer derivatives have been widely used in recent years. Although this α-methylstyrene dimer derivative is less efficient than an alkyl mercaptan chain transfer agent, it is characterized by being odorless and easy to handle and having little influence on the stability of the polymer such as discoloration.

  Such an α-methylstyrene dimer derivative can be obtained by subjecting α-methylstyrene to a dimerization reaction under acidic conditions. However, in this method, not only 2,4-diphenyl-4-methyl-1-pentene useful as a chain transfer agent, but also 2,4-diphenyl-4-methyl-2-pentene and saturated dimer 1,1, Since 3-trimethyl-3-phenylindane and trimer (2,4,6-triphenyl-4,6-dimethyl-1-heptene) are also by-produced, there is a problem that the yield of the target product is low. It was. For this reason, development of manufacturing methods for solving such problems has been performed, and in recent years, inexpensive and high-purity products have been obtained (see, for example, Patent Documents 1 to 4).

  On the other hand, styrene dimer derivatives containing functional groups such as hydroxyl, vinyl and amino groups can introduce reactive functional groups at the ends of polymer chains in addition to their functions as chain transfer agents. It is considered useful. However, it is difficult to produce a styrene dimer derivative having a functional group, and many problems remain including examples of its production such as the use of a special metal catalyst shown in Patent Document 5 or Patent Document 6, for example. ing.

  On the other hand, in recent years, it has been reported that by introducing a phenol group at the polymerization terminal of polystyrene, the compatibility between the polyacrylate resin and the polystyrene resin is improved (Non-patent Document 1), and the phenol group is easily added to the polystyrene terminal. Attention has been focused on hydroxystyrene dimer derivatives capable of introducing.

  Regarding the hydroxystyrene dimer derivative, for example, Non-Patent Documents 2 to 8 report the molecular structure and bioactive function of several types.

Japanese Patent Publication No.57-10850 JP-A-7-82180 Japanese Patent Laid-Open No. 8-176028 JP-A-9-194402 Japanese translation of PCT publication No. 2002-503645 JP 2002-241338 A

Shimon Tanaka, Haruo Nishida, and Takeshi Endo, Macromolecules, 2009, 42 (1), 293-298. Hideo Ohashi et al., Gifu University Agricultural Research Bulletin (52), 131-139 (1987). S. Suzuki, T. Umezawa and M. Shimada, J. Chem. Soc., Perkin Trans. 1, 2001 3252-3257. D. M. Skytte et al., J. Med. Chem., 2006, 49, 436-440. R. Bernini et al., Tetrahedron, 2007, 63, 9663-9667. T. Higashimura et al., Polymer Journal, 13, 563-568 (1981). K. Kodaira et al., Makromol. Chem., Rapid Commun., 1, 427-431 (1980). O. Frank et al., J. Agric. Food. Chem., 55, 1945-1954 (2007).

  However, it has not been found that known hydroxystyrene dimer derivatives can be used as chain transfer agents that are molecular weight regulators in radical polymerization reactions, and no effective production method has been disclosed. is there. Under such circumstances, the present invention has found that a hydroxystyrene dimer derivative having a predetermined characteristic structure is useful as a chain transfer agent in a radical polymerization reaction, and has completed the present invention.

（式中、置換基Ｒ¹およびＲ³は水素原子、アルコキシ基またはアセトキシ基のいずれかであり、Ｒ²はアセチル基またはアルキル基のいずれかである）。
That is, the present invention provides a method of polymerizing the radical polymerizable monomer used chain transfer agent consisting of Ruhi mud carboxymethyl dimer derivatives having a structure of Formula (1) below, and the chain transfer agent.

(In the formula, substituents R ¹ and R ³ are either a hydrogen atom, an alkoxy group or an acetoxy group, and R ² is either an acetyl group or an alkyl group).

More specifically, the present invention is a chain transfer agent comprising a hydroxystyrene dimer derivative represented by the following formula (2).

Further, it is a hydroxystyrene dimer derivative represented by the following formula (3).

これらのヒドロキシスチレンダイマー誘導体は、芳香環のフェノール性ヒドロキシル基が適当な保護基より保護されていることを特徴としている。 Furthermore, it is a hydroxystyrene dimer derivative represented by the following formula (4).

These hydroxystyrene dimer derivatives are characterized in that the phenolic hydroxyl group of the aromatic ring is protected by a suitable protecting group.

（式中、置換基Ｒ¹、Ｒ²、Ｒ³およびＲ⁴は、水素、ヒドロキシル基またはメトキシ基のいずれかである）で表されるヒドロキシケイ皮酸誘導体を塩基触媒およびプロティックソルベントの存在下で加熱してヒドロキシスチレンダイマー誘導体を得る製法を提供する。 Furthermore, as these production methods, the formula (5):

(Wherein the substituents R ¹ , R ² , R ³ and R ⁴ are either hydrogen, hydroxyl or methoxy) and the presence of a base catalyst and a protic solvent A process for obtaining a hydroxystyrene dimer derivative by heating under is provided.

  Moreover, this invention is a chain transfer agent which consists of a hydroxy styrene dimer derivative of a structure of above-described Formula (1)-(4).

  And this invention is a polymerization method of the radically polymerizable monomer characterized by polymerizing a radically polymerizable monomer using the said chain transfer agent.

  As described above, known hydroxystyrene dimer derivatives have only been reported for their presence and bioactive functions. In contrast, the present invention has found and provided a hydroxystyrene dimer derivative having a structure useful in the field of radical polymerization. This hydroxystyrene dimer derivative is used as a chain transfer agent in the polymerization of radically polymerizable monomers, so that it is possible to easily introduce a phenol group to the polymer terminal from its chain transfer mechanism. It also has excellent functionality. According to the industrially useful production method according to the present invention, the novel hydroxystyrene dimer derivative of the present invention could be produced for the first time. In addition, there is also an effect that easily available ferulic acid can be effectively used as a raw material.

The amount of raw ferulic acid, the amount of styrene derivative obtained and the amount of intermediate dimer are shown over time. (A) is a graph when ethylene glycol is used as a solvent, and (b) is toluene as a solvent. It is a graph of the case.

In the following, preferred embodiments of the present invention will be described. However, the present invention is not limited to these embodiments, and various modifications can be made within the spirit and the spirit of the present invention. Needless to say.
As shown in the following formula (1), the hydroxystyrene dimer derivative according to the present invention has a plurality of acetoxy groups or alkoxy groups on the aromatic ring in addition to the styrene dimer structure having an internal double bond (internal olefin). It is characterized by having. For this reason, this structure is introduced at the end of the polymer or copolymer to be produced.

The hydroxystyrene dimer derivative according to the present invention can be specifically produced by, for example, the methods shown in the following reaction formulas (a) to (d). It is possible to manufacture by applying various synthesis methods using characteristics based on types.
First, the hydroxystyrene dimer derivative of the present invention can be specifically produced by the method shown in the following reaction formula (a).

Furthermore, hydroxystyrene dimer derivatives having different substituents can be produced by the methods shown in, for example, the following reaction formula (b), reaction formula (c) and reaction formula (d).

  An intermediate having an OH group at the 4-position of the aromatic ring (formula (6)) or an intermediate having an OH group at the 4-position of the aromatic ring and a methoxy group at the 3-position (formulas (7), (8)) Since these OH groups and methoxy groups act as radical traps and become polymerization inhibitors, they cannot be used for radical polymerization reactions, and these intermediates are unstable compounds. On the other hand, hydroxystyrene dimer derivatives (formulas (2), (3), (4), (10)) obtained from these intermediates are stable compounds, and as chain transfer agents as will be described in detail later. It can be used for radical polymerization reactions.

As described above, in the production method of the present invention, a cinnamic acid derivative having a hydroxyl group at the 4-position is suitably used as a raw material. Specific cinnamic acid derivatives used in the production method of the present invention include 4-hydroxycinnamic acid (R ¹ = R ² = R ³ = R ⁴ = H), 3-methoxy-4-hydroxy cinnamic acid ( Ferulic acid: The structural formula is shown in the following formula (11)) (R ¹ = R ² = R ⁴ = H, R ³ = OMe), 3,4-dihydroxycinnamic acid (caffeic acid) (R ¹ = R ² = R ⁴ = H, R ³ = OH), 3,5-dimethoxy-4-hydroxycinnamic acid (sinapic acid) (R ¹ = R ⁴ = H, R ² = R ³ = OMe), etc. . Using these hydroxycinnamic acid derivatives as raw materials, a decarboxylation reaction and a subsequent dimerization reaction are performed, and then an acetylation or an alkylation reaction is performed to obtain a target hydroxystyrene dimer derivative.

  The base catalyst used for causing the decarboxylation reaction and the dimerization reaction continuously is not particularly limited. For example, an alkylamine (methyl group, ethyl group, carbon number including a linear or branched molecular chain). 3 alkyl groups (n-propyl, iso-propyl), C4 alkyl groups (n-butyl, iso-butyl, sec-butyl, tert-butyl) and other alkylamines having up to 20 carbon atoms), piperidine and pyrrolidine Specific examples include cyclic amines such as aniline, aromatic amines such as aniline, nitrogen-containing aromatic compounds such as pyridine, alkali metal hydroxides such as sodium hydroxide, and solid bases supported on polymer substrates. In order to obtain the target product with good yield, it is preferable to use one that is soluble in the solvent used.

  The amount of these base catalysts used is such that the reaction proceeds in an amount of 1/100 to 5 (molar ratio) with respect to 1 mol of the raw hydroxycinnamic acid derivative. Is preferably 0.5 to 5 (molar ratio) with respect to 1 mol of the hydroxycinnamic acid derivative. Preferably, it is 1-5 (molar ratio). When the amount of the base catalyst is less than 0.5 mol relative to 1 mol of the hydroxycinnamic acid derivative, the reaction may be stopped by the first stage of decarboxylation. In order to obtain a hydroxystyrene dimer with a high yield, it is important to use as much as possible even within a molar ratio of 0.5 to 5.

  The solvent used in the production method of the present invention needs to contain a protic solvent that dissociates protons. Although this protic solvent is not particularly limited, for example, one or more selected from the group consisting of methanol, ethanol, butanol, propanol, 2-propanol, ethylene glycol, diethylene glycol, water and the like can be used. In addition to these protic solvents, in addition to aromatic solvents such as benzene, toluene, xylene, chlorobenzene, and ethylbenzene, aliphatic hydrophobic solvents such as n-hexane, cyclohexane, dimethylcyclohexane, n-heptane, Even in a mixed system combining one or two or more solvents selected from hydrophobic solvent groups such as n-octane, isooctane, n-nonane, n-decane and kerosene, the target product can be obtained efficiently and in high yield. Is possible.

  In the production method of the present invention, heating is required for the decarboxylation reaction of the hydroxycinnamic acid derivative. The heating temperature is not particularly limited, but the reaction proceeds rapidly by heating at about 50 ° C. to 250 ° C. More preferably, it is a high temperature of 100 ° C. or higher. The reaction can be carried out either in an open system in which the pressure does not increase even when heated, or in a closed system in which the pressure increases due to high temperature heating. The heating method during the reaction is not particularly limited, but a normal heating method such as an oil bath may be used. The atmosphere during heating is preferably free of oxygen. However, since the reaction system is covered with carbon dioxide gas generated by the reaction, oxygen is temporarily blocked. As a precaution, the reaction may be performed under a nitrogen stream.

In the production method of the present invention, a hydroxycinnamic acid derivative is heated in the presence of a base catalyst and a protic solvent, whereby a decarboxylation reaction and a subsequent dimerization reaction are continuously performed to obtain a hydroxystyrene dimer. The obtained hydroxystyrene dimer is characterized by reacting an acetylating agent or an alkylating agent, and these reactions can utilize generally known reactions. For example, as the acetylating agent, generally at least one selected from acetic anhydride, acetyl chloride, and acetyl bromide can be used. Use of a catalyst is effective for allowing the acetylation reaction to proceed efficiently. The catalyst is not particularly limited, but alkylamine (methyl group, ethyl group, alkyl group having 3 carbon atoms (n-propyl, iso-propyl), alkyl group having 4 carbon atoms (n-butyl, iso-butyl, sec) Alkylamines having up to 20 carbon atoms such as -butyl and tert-butyl), cyclic amines such as piperidine and pyrrolidine, aromatic amines such as aniline, nitrogen-containing aromatic compounds such as pyridine, and alkali metals such as sodium hydroxide. It is preferable to use a hydroxide, a solid base supported on a polymer substrate, or the like. In the present invention, the base used for the decarboxylation reaction may be used as it is, or may be added according to the progress of the reaction.
On the other hand, for the alkylation reaction, a general-purpose method using alkyl halide or dimethyl sulfate, or a method of reacting alcohol such as methanol by Mitsunobu reaction can be used. In order to obtain the target product by Mitsunobu reaction, phosphorus compounds such as triphenylphosphine, diethylphenylphosphine, diphenyl-2-pyridylphosphine, tributylphosphine, polystyrene resin-fixed diphenylphosphine derivatives, azodicarboxylic acid dimethyl ester, azodicarboxylic It is effective to use in combination with azo compounds such as acid diethyl ester, azodicarboxylic acid diisopropyl ester, N, N, N, N, -tetramethylazodicarboxylic acid amide, azodicarboxylic acid di-2-methoxyethyl ester .

As the radically polymerizable monomer that can be used in the present invention, specifically,
(A) Aromatic ethylenically unsaturated monomers: styrenes such as styrene, α-methylstyrene, vinyltoluene, hydroxystyrene, halogen substituted products of styrenes such as vinylnaphthalene, dichlorostyrene, etc.
(B) Aliphatic ethylenically unsaturated monomer: ethylene, propylene, butene, isobutylene, pentene, heptene, diisobutylene, octene, dodecene, octadecene, butadiene, isoprene, etc.
(C) alicyclic ethylenically unsaturated monomer: cyclopentadiene, pinene, limonene, indene, bicyclopentadiene, ethylidene norbornene, etc.
(D) Alkyl (meth) acrylate having an alkyl group having 1 to 50 carbon atoms: methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate , Dodecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, eicosyl (meth) acrylate,
(E) hydroxyl group-containing (meth) acrylate: hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, etc.
(F) Amide-containing ethylenically unsaturated monomer: (meth) acrylamide, N-methylol (meth) acrylamide, etc.
(G) Examples include unsaturated organic silane compounds such as 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, and vinyltrimethoxysilane, but are not particularly limited thereto. From the viewpoint of radical polymerizability and availability of monomers, methacrylic acids, acrylic acids, α, β-unsaturated carboxylic acids and styrenes are preferred. Moreover, these radically polymerizable monomers may use only 1 type, and may use it in combination of 2 or more type.

The radical polymerization initiator used for the polymerization is preferably an azo compound or an organic peroxide, and is selected on the basis of a 10-hour half-life temperature corresponding to the polymerization temperature. Specific examples of the organic peroxide include 2,4-dichlorobenzoyl peroxide, t-butyl peroxypivalate, o-methylbenzoyl peroxide, bis-3,5,5-trimethylhexanoyl peroxide, octa Noyl peroxide, t-butylperoxy-2-ethylhexanoate, cyclohexanone peroxide, benzoyl peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, lauroyl peroxide, diisopropylbenzene hydroperoxide, t-butyl hydroperoxide , Di-t-butyl peroxide and the like. Specific examples of the azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyl-4). -Methoxyvaleronitrile) and the like. Among these, benzoyl peroxide, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyl-4) -Methoxyvaleronitrile) is preferred because it is readily available and easy to handle. These radical polymerization initiators may be used alone or in combination of two or more.
The addition amount of the radical polymerization initiator is preferably in the range of 0.0001 parts by mass to 10 parts by mass with respect to 100 parts by mass of the total amount of radical polymerizable monomers. When the added amount of the radical polymerization initiator exceeds 10 parts by mass, the residue of the radical polymerization initiator itself remains in the polymer, and there is a high possibility that the quality of the polymer is deteriorated. On the other hand, when the addition amount is less than 0.0001 part by mass, the degree of polymerization of the polymer is unnecessarily high, resulting in excessive polymerization, and the reaction time until the end of the polymerization becomes long, making it unsuitable for actual production.

  Although it does not specifically limit regarding polymerization temperature, In order to achieve high chain transfer efficiency, it is preferable to superpose | polymerize at 40-250 degreeC, More preferably, it is 60-160 degreeC.

  The hydroxystyrene dimer derivative according to the present invention can be used for radical polymerization of various polymers or copolymers prepared from radically polymerizable monomers or mixtures thereof, and has a chain that reduces the molecular weight of these polymers or copolymers. Useful as a transfer agent. The degree of this molecular weight reduction can be adjusted by the amount of chain transfer agent added, and the amount of chain transfer agent addition is determined by the molecular weight of the desired polymer or copolymer.

  As a method for producing a polymer or copolymer by performing polymerization using the chain transfer agent of the present invention, generally known polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization can be used. However, it is not limited to the above polymerization method.

EXAMPLES Hereinafter, although a manufacture example, an Example, and a comparative example demonstrate this invention concretely, this invention is not limited at all by these manufacture example, an Example, and a comparative example.
Here, the structure of the hydroxystyrene dimer derivative synthesized in the production example was confirmed by ¹ H-NMR, ¹³ C-NMR (manufactured by Bruker, AVANCE400) and ESI-TOF / MS (manufactured by Applied Bio, Mariner). The number average molecular weight (= Mn), weight average molecular weight (= Mw), and molecular weight distribution (= d (= Mw / Mn)) of the synthesized polymer are GPC (Gel Permeation Chromatograph: Waters, Alliance 2690). ) And polystyrene as a standard.

(Production Example 1)
4-acetoxystyrene dimer (produced by the above-described reaction formula (a): acetylation);
[1,3-Bis (4'-acetoxyphenyl) butene]
A solution in which 6.56 g (40 mmol) of 4-hydroxycinnamic acid (p-coumaric acid) was dispersed in 100 ml of toluene and 1.6 g (40 mmol) of NaOH dissolved in 60 ml of water was added and refluxed overnight. After standing to cool, the aqueous phase was neutralized and then transferred to a separatory funnel to separate the aqueous phase. The obtained organic phase was washed with water, dried over MgSO ₄ , and then the solvent was distilled off under reduced pressure to obtain 4.26 g of crude 4-hydroxystyrene dimer (intermediate dimer of formula (6)).
The obtained crude 4-hydroxystyrene dimer was dissolved in 20 ml of pyridine, and 4.0 ml (42.3 mmol) of acetic anhydride was added and stirred overnight at room temperature. After crushed ice was added to stop the reaction, 80 ml of ethyl acetate was added and the mixture was transferred to a separatory funnel and washed with saturated KHSO ₄ , water, saturated NaHCO ₃ and saturated brine in this order. After drying with MgSO ₄ , the solvent was distilled off, and the residue was purified by column chromatography to obtain a purified product as a colorless oil. When the obtained purified product was subjected to instrumental analysis as described below, it was 4-acetoxystyrene dimer (dimer of formula (2): yield 4.35 g, yield 67%). The instrumental analysis results are shown below.
¹ H-NMR (400MHz, CDCl ₃ ) δ1.44 (d, 3H, J = 8.0 Hz, CH ₃ ), 2.27 (s, 3H, acetyl), 2.28 (s, 3H, acetyl), 3.63 (m, 1H , CH), 6.30 (dd, 1H, J = 4.0 and 16.0 Hz, CH =), 6.39 (d, 1H, J = 16.0 Hz, CH =), 6.27-7.36 (m, 8H, Ar-H) ppm; ¹³ C NMR (CDCl ₃ ) (21.04, 21.06, 21.09, 41.84, 121.40, 121.52, 126.98, 127.66, 128.17, 135.10, 135.18, 142.91, 148.92, 149.62, 169.40, 169.55 ppm; MS (ESI-TOF) calcd for [ C ₂₀ H ₂₀ O ₄ ] ⁺ 325.14, found 325.10 [M + H] ⁺ .

(Production Example 2)
4-methoxystyrene dimer (manufactured by application example of reaction formula (d) described above: alkylation);
[1,3-Bis (4'-methoxyphenyl) butene]
Crude 4-hydroxystyrene dimer (1.03 g, 4.28 mmol) obtained by the same reaction as in Production Example 1 was dissolved in dichloromethane (50 ml), triphenylphosphine (3.0 g, 11.4 mmol), and methanol (1.0 ml). (24.7 mmol) and 6.0 ml of diisopropyl azodicarboxylic acid (40% toluene solution) were added and stirred at room temperature overnight. After the solvent was distilled off, the residue was purified by column chromatography to obtain a colorless oily purified product. When the obtained purified product was subjected to instrumental analysis as described below, it was 4-methoxystyrene dimer (yield 0.79 g, yield 69%). The instrumental analysis results are shown below.
¹ H-NMR (400MHz, CDCl ₃ ) δ1.42 (d, 3H, J = 8.0 Hz, CH ₃ ), 3.57 (m, 1H, CH), 3.79 (s, 6H, OCH ₃ ), 6.22 (dd, 1H, J = 4.0 and 16.0 Hz, CH =), 6.33 (d, 1H, J = 16.0 Hz, CH =), 6.81-7.30 (m, 8H, Ar-H) ppm; ¹³ C NMR (CDCl ₃ ) ( 21.06, 21.43, 41.65, 55.28, 113.62, 113.82, 113.89, 127.20, 127.58, 127.79, 128.19, 130.43, 133.51, 137.98, 157.95, 158.76 ppm; MS (ESI-TOF) calcd for [C ₁₈ H ₂₀ O ₂ ] ⁺ 269.15, found 270.17 [M + H] ⁺ .

(Production Example 3)
4-acetoxy-3-methoxystyrene dimer (produced by the above-described reaction formula (b): acetylation);
[1,3-Bis (4'-acetoxy-3'-methoxyphenyl) butene]
19.42 g (0.1 mol) of 4-hydroxy-3-methoxycinnamic acid (ferulic acid) was dispersed in 150 ml of toluene, and 11.7 g (0.115 mol) of triethylamine and 50 ml of water were added and refluxed overnight. After standing to cool, the aqueous phase was neutralized and then transferred to a separatory funnel to separate the aqueous phase. The obtained organic phase was washed with water, dried over MgSO ₄ , and then the solvent was distilled off under reduced pressure to obtain 10.16 g of crude 4-hydroxy-3-methoxystyrene dimer (intermediate dimer of formula (7)). .
The obtained crude 4-hydroxy-3-methoxystyrene dimer was dissolved in 40 ml of pyridine, and 8.0 ml (84.6 mmol) of acetic anhydride was added and stirred overnight at room temperature. After crushed ice was added to stop the reaction, 150 ml of ethyl acetate was added and the mixture was transferred to a separatory funnel and washed with saturated KHSO ₄ , water, saturated NaHCO ₃ , and saturated brine in this order. After drying with MgSO ₄ , the solvent was distilled off, and the residue was purified by column chromatography to obtain a purified product as a white solid. When the obtained purified product was subjected to instrumental analysis as described below, it was 4-acetoxy-3-methoxystyrene dimer (dimer of formula (3): yield 10.32 g, yield 72%). The instrumental analysis results are shown below.
¹ H-NMR (400MHz, CDCl ₃ ) δ1.46 (d, 3H, J = 8.0 Hz, CH ₃ ), 2.31 (s, 3H, acetyl), 2.31 (s, 3H, acetyl), 3.62 (m, 1H , CH), 3.83 (s, 3H, OCH ₃ ), 3.84 (s, 3H, OCH ₃ ), 6.30 (dd, 1H, J = 4.0 and 16.0 Hz, CH =), 6.39 (d, 1H, J = 16.0 Hz, CH =), 6.83-6.99 (m, 6H, Ar-H) ppm; ¹³ C NMR (CDCl ₃ ) (21.64, 20.68, 21.01, 42.30, 55.83, 55.84, 109.78, 111.59, 118.80, 119.34, 122.56, 122.71, 128.09, 135.12, 136.50, 138.03, 138.86, 144.33, 150.88, 151.02, 169.12, 169.25 ppm; MS (ESI-TOF) calcd for [C ₂₂ H ₂₄ O ₆ ] ⁺ 385.16, found 385.20 [M + H] ⁺ .

(Production Example 4)
Synthesis of 3,4-dimethoxystyrene dimer (prepared by the aforementioned reaction formula (d): alkylation);
[1,3-Bis (3 ', 4'-dimethoxyphenyl) butene]
1.96 g (6.5 mmol) of crude 4-hydroxy-3-methoxystyrene dimer obtained by the same reaction as in Production Example 3 was dissolved in 50 ml of dichloromethane, 4.88 g (18.6 mmol) of triphenylphosphine, methanol 1 .0ml (24. 7m mol), and stirred at room temperature overnight diisopropyl azodicarboxylate (40% toluene solution) 10.0 ml. After the solvent was distilled off, the residue was purified by column chromatography to obtain a colorless oily purified product. When the obtained purified product was subjected to instrumental analysis as described below, it was 3,4-dimethoxystyrene dimer (dimer yield of formula (10): 1.49 g, yield: 70%). The instrumental analysis results are shown below.
¹ H-NMR (400MHz, CDCl ₃ ) δ1.45 (d, 3H, J = 8.0 Hz, CH ₃ ), 3.58 (m, 1H, CH), 3.87 (s, 3H, OCH ₃ ), 3.88 (s, 6H, OCH ₃ ), 6.23 (dd, 1H, J = 4.0 and 16.0 Hz, CH =), 6.33 (d, 1H, J = 16.0 Hz, CH =), 6.79-6.92 (m, 6H, Ar-H) ^13C NMR (CDCl ₃ ) (21.30, 42.06, 55.80, 55.88, 55.92, 108.58, 110.79, 111.11, 111.20, 119.02, 119.12, 127.98, 130.68, 133.55, 138.40, 147.43, 148.38, 148.89, 148.98 ppm; MS (ESI-TOF) calcd for [C ₂₀ H ₂₄ O ₄ ] ⁺ 329.17, found 329.18 [M + H] ⁺ .

(Production Example 5)
4-acetoxy-3,5-dimethoxystyrene dimer (prepared by the above-described reaction formula (c); acetylation);
[1,3-Bis (4'-acetoxy-3 ', 5'-dimethoxyphenyl) butene]
4.80 g (21.4 mmol) of 4-hydroxy-3,5-dimethoxycinnamic acid was dispersed in 50 ml of ethylene glycol, and 3.0 ml (21.6 mmol) of triethylamine was added and refluxed overnight. After standing to cool, the mixture was neutralized, 100 ml of water was added, transferred to a separatory funnel, and extracted three times with 60 ml of chloroform. The obtained chloroform phases were combined, washed with water and dried over MgSO ₄ . The solvent was distilled off under reduced pressure to obtain 5.30 g of crude oily 4-hydroxy-3,5-dimethoxystyrene dimer as a red oil.
The resulting crude 4-hydroxy-3,5-dimethoxy dimer was dissolved in pyridine 20 ml, and stirred overnight at room temperature acetic anhydride 4.0ml (42. 3m mol). After crushed ice was added to stop the reaction, 80 ml of ethyl acetate was added and the mixture was transferred to a separatory funnel and washed with saturated KHSO ₄ , water, saturated NaHCO ₃ and saturated brine in this order. After drying with MgSO ₄ , the solvent was distilled off, and the residue was purified by column chromatography to obtain a purified product as a colorless oil. When the obtained purified product was subjected to instrumental analysis as described below, it was 4-acetoxy-3,5-dimethoxystyrene dimer (yield 2.48 g, yield 52%). The instrumental analysis results are shown below.
¹ H-NMR (400MHz, CDCl ₃ ) δ1.47 (d, 3H, J = 8.0 Hz, CH ₃ ), 2.33 (s, 3H, acetyl), 2.34 (s, 3H, acetyl), 3.62 (m, 1H , CH), 3.82 (s, 6H, OCH ₃ ), 3.83 (s, 6H, OCH ₃ ), 6.30 (dd, 1H, J = 4.0 and 16.0 Hz, CH =), 6.37 (d, 1H, J = 16.0 Hz, CH =), 6.50 (s, 2H, Ar-H), 6.62 (s, 2H, Ar-H) ppm; ¹³ C NMR (CDCl ₃ ) (20.46, 20.51, 20.86, 42.77, 56.13, 56.14, 102.82 , 103.96, 127.01, 127.90, 128.52, 135.07, 135.85, 143.83, 152.00, 152.12, 168.84, 169.00 ppm; MS (ESI-TOF) calcd for [C ₂₄ H ₂₈ O ₈ ] ⁺ 445.18, found 445.16 [M + H] ⁺ .

(Production Example 6)
4-Hydroxy-3-methoxycinnamic acid (ferulic acid) 10 mmol as a raw material, 4-hydroxy-3-methoxystyrene dimer (intermediate dimer, structural formula: reaction formula (b), The conditions of the solvent for obtaining the formula (7) in (d) were examined. Reaction was carried out under the conditions shown in Table 1, using an equivalent amount (eq: 10 mmol) of triethylamine (10 mmol) to ferulic acid as a base catalyst. The end point of the reaction was confirmed by thin phase chromatography (TLC), and the time elapsed until disappearance of the raw material and the yield of the obtained 4-hydroxy-3-methoxystyrene dimer were examined by NMR. The production rate of the styrene derivative and the yield of the intermediate dimer are those after 5 hours from the start of the reaction.
In this production example, a basic solvent, which is a protic solvent, using only ethylene glycol or water alone is referred to as Examples 1 and 2, only toluene other than the protic solvent, only N, N-dimethylformamide is used. Comparative Examples 1 to 3 were made using only diglyme. In each example, the amount of the solvent used was 20 ml, and the reaction temperature was 100 ° C. Further, the ratio of the raw material ferulic acid converted to a styrene derivative or an intermediate dimer 5 hours after the start of the reaction is shown as the raw material conversion rate.

From Table 1 above, it can be seen that 4-hydroxy-3-methoxystyrene dimer may or may not be obtained depending on the type of solvent used. That is, an intermediate dimer is obtained by using only protic solvent ethylene glycol or water alone, and particularly when ethylene glycol is used, an intermediate dimer is obtained in high yield. On the other hand, in the case of using a solvent (toluene, N, N-dimethylformamide, diglyme) other than protic solvent, an intermediate dimer was not obtained only by producing a styrene derivative from ferulic acid.
Here, when only ethylene glycol (protic solvent) (Example 1) or only toluene (Comparative Example 1) is used as the solvent, ferulic acid, the obtained styrene derivative, and the production rate of the intermediate dimer The change with time is illustrated in FIG. In the case of using ethylene glycol ((a) in the figure), ferulic acid is converted into a styrene derivative and an intermediate dimer over time, but the styrene derivative decreases from the middle, and the intermediate dimer continues to increase. Yes. In contrast, in the case of using toluene ((b) in the same figure), ferulic acid was converted and styrene derivatives were increased, but no intermediate dimer was produced. That is, it is suggested that the protic solvent is greatly involved in the dimerization reaction after the decarboxylation reaction.

(Production Example 7)
Using 10 mmol of 4-hydroxy-3-methoxycinnamic acid (ferulic acid), the conditions under which 4-hydroxy-3-methoxystyrene dimer serving as an intermediate of the target product was obtained were studied.
Reaction was carried out under the conditions shown in Table 2 using 20 ml of a toluene / water mixed solvent (mixing ratio 5: 3 parts by volume) and various base catalysts. The end point of the reaction was confirmed by thin phase chromatography (TLC), and the yield of 4-hydroxy-3-methoxystyrene dimer (intermediate) obtained until the disappearance of the raw material was examined by NMR.

  From Table 2 above, it can be seen that the yield of 4-hydroxy-3-methoxystyrene dimer obtained varies greatly depending on the type of base catalyst used. In addition, when potassium acetate which is a weak base was used as a base catalyst (Comparative Example 4), an appropriate intermediate was hardly obtained. However, a styrene derivative (monomer) derived from ferulic acid was produced.

そして、それらの結果を、連鎖移動剤を含まない比較例５と合わせて表３に示す。
尚、表中に記載した転換率は重合開始後においてスチレンモノマーがポリマーに転換した割合を示している。以下の表４〜７についても同様である。

(Example of polymerization)
(Examples 7 to 9, Comparative Example 5)
Examples 7-9 illustrate the styrene solution polymerization method at 60 ° C. according to the present invention, and include a control example (Comparative Example 5) in which no chain transfer agent is used. As a polymerization initiator, azobisisobutyronitrile was used in an amount of 0.06 mol% based on 1 mol of the monomer, and 4-acetoxystyrene dimer (structure formula: Formula (2)) obtained in Production Example 1 was used as a chain transfer agent. . Each component was filled in 20 ml of Schlenk, sealed with a three-way cock, and then freeze-degassed three times under a nitrogen stream, and used for the polymerization. The polymerization was carried out for 3 hours by heating to 60 ° C. under a nitrogen stream. The molecular weight and molecular weight distribution of the obtained polymer were measured using a polymer powder obtained by cooling the solution after completion of polymerization to room temperature, reprecipitating with tetrahydrofuran / methanol, filtering them, and drying. Such a polymerization reaction formula is shown in the following formula.

The results are shown in Table 3 together with Comparative Example 5 that does not contain a chain transfer agent.
In addition, the conversion rate described in the table | surface has shown the ratio which the styrene monomer converted into the polymer after superposition | polymerization start. The same applies to Tables 4 to 7 below.

  From Table 3 above, the molecular weight of the polymer obtained decreased with the increase in the amount of chain transfer agent added (Example 9 <Example 8 <Example 7), and the chain transfer agent functioned. I understand that.

(Examples 10 to 12, Comparative Example 6)
It implemented on the conditions similar to Examples 7-9 and the comparative example 5 except having used 4-methoxy styrene dimer obtained by manufacture example 2 as a chain transfer agent. The results are shown in Table 4 together with Comparative Example 6 containing no chain transfer agent.

  From the above Table 4, the molecular weight of the obtained polymer was lowered according to the increase in the amount of addition of the chain transfer agent (Example 12 <Example 11 <Example 10). I understand that.

(Examples 13 to 15, Comparative Example 7)
It implemented on the conditions similar to Examples 7-9 except having used 4-acetoxy-3-methoxy styrene dimer (ferulic acid origin) obtained by manufacture example 3 as a chain transfer agent. The results are shown in Table 5 together with Comparative Example 7 containing no chain transfer agent.

  From Table 5 above, the molecular weight of the polymer obtained decreased with the increase in the amount of chain transfer agent added (Example 15 <Example 14 <Example 13), and the chain transfer agent functioned. I understand that.

(Examples 16 to 18, Comparative Example 8)
It implemented on the conditions similar to Examples 7-9 and the comparative example 5 except having used the 3, 4- dimethoxy styrene dimer obtained by manufacture example 4 as a chain transfer agent. The results are shown in Table 6 together with Comparative Example 8 containing no chain transfer agent.

  From Table 6 above, the molecular weight of the polymer obtained decreased with the increase in the amount of chain transfer agent added (Example 18 <Example 17 <Example 16), and the chain transfer agent functioned. I understand that.

(Examples 19 to 21, Comparative Example 9)
It implemented on the conditions similar to Examples 7-9 and the comparative example 5 except having used 4-hydroxy-3,5-dimethoxystyrene dimer obtained by manufacture example 5 as a chain transfer agent. The results are shown in Table 7 together with Comparative Example 9 containing no chain transfer agent.

From Table 7 above, the molecular weight of the polymer obtained decreased with the increase in the amount of chain transfer agent added (Example 21 <Example 20 <Example 19), and functioned as a chain transfer agent. I understand that.
In addition, the value of d indicating the molecular weight distribution obtained in Examples 7 to 21 and Comparative Examples 5 to 9 was within the range of 1.60 to 1.89 and was not an abnormal range.

Here, the efficiency of the chain transfer agent can be evaluated by a chain transfer constant CT derived from the following calculation formula (A).
CT = (1 / Xn-1 / Xn0) / ([T] / [M])
... (A)
(In the formula (A), CT is the chain transfer constant, Xn is the degree of polymerization of the polymer obtained in the polymerization with the addition of the chain transfer agent, and Xn0 is the polymer obtained in the polymerization with no addition of the chain transfer agent. The degree of polymerization, [T] is the chain transfer agent concentration, and [M] is the monomer concentration.)
Specifically, when styrene is used as the monomer, in the solution polymerization of styrene at a temperature of 60 ° C. in which the concentration ratio [T] / [M] of the chain transfer agent and styrene is changed, from the solution after 3 hours respectively. The obtained polymer is analyzed by GPC, and the number average molecular weight is determined. The degree of polymerization is calculated from the number average molecular weight, and the slope of a straight line obtained by plotting each value on a graph with 1 / Xn on the vertical axis and [T] / [M] on the horizontal axis is obtained. The slope of the straight line at this time corresponds to the chain transfer constant, and the larger the value of this chain transfer constant, the higher the chain transfer efficiency and the better the chain transfer agent.

  When the five types of hydroxystyrene dimer derivatives shown in the production examples were evaluated by the above-described method, the 4-acetoxy-3-methoxystyrene dimer produced in Production Example 3 (reaction) was obtained as shown in Table 8 below. It can be seen that the structural formula (3) in formula (b) is the most excellent as a chain transfer agent. However, since the dimer obtained by Production Examples 1, 2, 4, and 5 also has a chain transfer constant within a practically allowable range (0.046, 0.0455, 0.049, 0.040). As a chain transfer agent, it has appropriate performance.

As a conventional example, a polymerization test was performed in the same manner as in Example 7 using a commercially available α-methylstyrene dimer to obtain a chain transfer constant. The results are also shown in Table 8. Since this α-methylstyrene dimer has an external olefin, it is known that chain transfer efficiency (chain transfer constant = 0.129) is good. However, since the α-methylstyrene dimer does not have a substituent on the aromatic ring, a substituent derived from a chain transfer agent cannot be added to the end of the polymer polymerized using the α-methylstyrene dimer. Then, although it was intended to introduce a substituent into an aromatic ring as in Patent Documents 5 and 6, various problems occurred as described above.
On the other hand, the hydroxystyrene dimer derivative obtained by the present invention has an internal olefin in the straight chain between two aromatic rings, so that the chain transfer efficiency is somewhat lower than that of the α-methylstyrene dimer, but it is practical. In addition, the molecular weight of the polymer can be adjusted, and a new component or functional group can be added to the polymer due to the substituent of the aromatic ring.

  Since the hydroxystyrene dimer derivative concerning this invention is comprised as mentioned above, it can synthesize | combine comparatively easily by using the hydroxycinnamic acid derivative which is industrially easy to obtain as a raw material. The obtained hydroxystyrene dimer derivative is excellent in storability because the hydroxyl group is protected by a protecting group, and is also a good substance as a chain transfer agent for a radical polymerizable monomer. Furthermore, there is a possibility that it can be used as a compatibility improver for polyacrylate resin / polystyrene resin by taking advantage of the feature that enables introduction of a phenolic hydroxyl group at the polymer terminal. In addition, since 4-acetoxy-3-methoxystyrene dimer can be manufactured using ferulic acid, which can be supplied at low cost and in large quantities as a by-product during the manufacture of rice bran oil in recent years, plant origin ( It is also expected to be a good material as a raw material for producing bio-based polymers.

Claims (7)

The following formula (1):

(Wherein the substituents R ¹ and R ³ are a hydrogen atom, or an alkoxy group or an acetoxy group, R ² is either an acetyl group or an alkyl group) consisting of hydroxy dimer derivative represented by A chain transfer agent characterized by that . The following formula (2):

A chain transfer agent comprising a hydroxystyrene dimer derivative represented by the formula: Formula (3) below:

A hydroxystyrene dimer derivative represented by: Equation (4) below:

A hydroxystyrene dimer derivative represented by: A chain transfer agent comprising the hydroxystyrene dimer derivative according to claim 3. The following formula (5):

(Wherein the substituents R ¹ , R ² , R ³ and R ⁴ are either hydrogen, hydroxyl or methoxy) and the presence of a base catalyst and a protic solvent The method for producing a hydroxystyrene dimer derivative according to any one of claims 1 to 4, wherein the hydroxystyrene dimer derivative is obtained by heating under heating. A method for polymerizing a radical polymerizable monomer, comprising polymerizing a radical polymerizable monomer using the chain transfer agent according to any one of claims 1, 2 and 5 .

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