JP2775942B2 - Polymer and method for producing the same - Google Patents

Description

The present invention relates to a novel polymer having an azo group in a molecule,
This novel polymer is useful as an initiator for radical polymerization.

[Prior Art] Various studies have been made on the production of polymers having an azo group in the molecular chain. For example, synthesis of the polymer by a method of using an azo compound as a polymerization initiator, terminating the polymerization at a low conversion rate, and leaving an azo group in a molecular chain has been studied (for example, diangevante macromolecular). Chemie (Die Angewandte Makromolecular Chemi
e), 98, 167, 1981). However, the azo group-containing polymers obtained by these radical polymerization methods have a wide molecular weight distribution. Therefore, there is a problem that it is difficult to control the molecular weight and the molecular weight distribution. Further, in the prior art, synthesis of a polymer having an azo group in a molecular chain by a condensation reaction between a polymer having a hydroxyl group at a terminal and an azo compound has been studied (for example, di-macromolecular.
Chemie (Die Mkromolecular Chemie), Vol. 183, 168
5, 1982). The polymer obtained by this method has an extremely wide molecular weight distribution, and it is difficult to obtain a polymer having one azo group in one molecular chain. In addition, in the condensation reaction, the ratio of raw materials charged greatly affects the reaction, and there is a problem that a quantitative reaction is difficult in a reaction between polymers because the molecular weight of the polymer has a distribution. In addition, the produced polymer has an ester group, and has a problem that it has no acid resistance.

As a study to improve these drawbacks, a polymer synthesized by anionic polymerization was bonded with AIBN (2,2'-azobisisobutyronitrile) to contain an azo group containing no ester group in the initiator skeleton. Synthetic studies of polymers have been studied (for example, European Polymer Journal, Vol. 12, p. 317, 197).
6 years). However, in this method, quantitative coupling of the polymer cannot be performed, and in order to perform a quantitative reaction, it was necessary to modify the terminal structure in order to increase the reactivity of the polymer terminal.

[Problems to be Solved by the Invention] As described above, in the prior art, the obtained polymer has a wide molecular weight distribution, low reactivity at the polymer terminal, and structurally has a problem in acid resistance in the initiator. Having an ester bond,
And there are drawbacks such as difficulty in quantitative reaction.

[Means for Solving the Problems] In order to improve the above drawbacks, as a result of intensive studies, the following general formula [III] Wherein R ² and R ³ represent an alkyl group having 1 to 18 carbon atoms or an aryl group, and R ⁵ and R ⁶ represent an alkyl group having 1 to 4 carbon atoms. The following general formula [V] obtained by polymerization using a polymerization initiator represented by the following general formula [IV] R ¹ -Li (where R ¹ represents an alkyl group or an aryl group) (Where R ¹ is an alkyl group or an aryl group, R ² and R ³ are an alkyl group or an aryl group having 1 to 18 carbon atoms, R ⁵ and R ⁶ are an alkyl group having 1 to 4 carbon atoms, or an alkoxy group, m is the degree of polymerization, anionic polymers of the following general formula represented by positive integers) [II] ClC (O) -R 4 -N = N-R 4 - By coupling with an azo compound represented by C (O) Cl [II] (where R ⁴ represents a methylene group having 1 to 18 carbon atoms, an arylene group, or an organic group containing a methylene group),
The present inventors have found that a novel polymer having no terminal structure modification, having a narrow molecular weight distribution, and having no ester structure alone can be synthesized.

 Hereinafter, the present invention will be described in detail.

The present invention relates to a novel polymer having an azo group in a molecular chain, which is obtained by binding the ends of a living polymer with an azo compound. Furthermore, details the general formula [II] ClC (O) -R 4 -N = N-R 4 -C (O) Cl [II] ( wherein, R ⁴ is methylene group having 1 to 18 carbon atoms, An azo compound represented by an arylene group or an organic group containing a methylene group); (Where R ² and R ³ represent an alkyl group or an aryl group having 1 to 18 carbon atoms, and R ⁵ and R ⁶ represent an alkyl group or an alkoxy group having 1 to 4 carbon atoms) A monomer is polymerized using an anionic polymerization initiator represented by the general formula [IV] R ¹ -Li [IV] (where R ¹ represents an alkyl group or an aryl group). The above general formula [V] (Where R ¹ is an alkyl group or an aryl group, R ² and R ³ are an alkyl group having 1 to 18 carbon atoms or an aryl group, and R ⁵ and R ⁶ are an alkyl group having 1 to 4 carbon atoms. Wherein m is a degree of polymerization and represents a positive integer) by reacting with an anionic polymer having a dispersity (w / n) of 1.01 to 1.3 represented by the following general formula [I]: (Where R ¹ is an alkyl group or an aryl group, R ² and R ³ are an alkyl group or an aryl group having 1 to 18 carbon atoms, and R ⁴ is a methylene group or an arylene group having 1 to 18 carbon atoms) Wherein R ⁵ and R ⁶ represent an alkyl group or an alkoxy group having 1 to 4 carbon atoms, m represents a degree of polymerization, and represents a positive integer. Group with a molecular weight of 5,000
100100,000 and a molecular weight dispersity (w / n) of 1.01
A new polymer of ~ 1.50.

Monomers that can be used in the present invention include styrene, α-methylstyrene, α-ethylstyrene, and other α-
β-n such as n-alkylstyrene and β-methylstyrene
-Alkylstyrene, o-methylstyrene, on-alkylstyrene such as p-methylstyrene, and pn-
Alkyl-styrene, o-methoxystyrene, p-methoxystyrene, etc., o-alkoxystyrene, p-alkoxystyrene, dialkyl-substituted styrenes such as 2,4-dimethylstyrene, and α-phenylstyrene (α-phenylstyrene) α-aryl-substituted styrene and the like are exemplified.

The above-mentioned monomer is preferably dehydrated in the order of calcium hydride and lithium aluminum hydride, and it is preferable to add a diluted initiator solution before use, dehydrate, and then purify by distillation. The anionic polymerization method of the above styrene polymer is known. As the anionic polymerization solvent, a cyclic ether such as tetrahydrofuran, an aromatic hydrocarbon such as benzene and toluene, a cycloaliphatic hydrocarbon such as cyclohexane, and an aliphatic hydrocarbon such as n-hexane are usually used.

As the anion polymerization catalyst, it is preferable to use an alkyl lithium catalyst, and examples thereof include methyl lithium, ethyl lithium, isopropyl lithium, s-butyl lithium, and t-butyl lithium. Anionic polymerization is usually performed at a low temperature of -78 ° C to room temperature, and the polymerization is usually performed for 5 minutes.
Complete in 20 minutes.

A method for bonding a living polymer synthesized by an anionic polymerization method with an azo compound will be described below. The method for producing the azo compound used in the present invention is known, and an azo compound having a carboxyl group at both terminals is used as a starting material. As azo compounds having a carboxyl group, 2,
2'-azobis-2-cyanodipropionic acid, 3,3'-azobis-3-cyanodibutylic acid, 4,4'-azobisdivaleric acid, 5,5'-
The following general formula [VI] such as azobis-5-cyanodicaproic acid (Where n represents an integer of 0 or more), 3,3'-azobis-3,3'-dimethyldipropionic acid, 4,4'-azobis-4,4'-
Dimethyl dibutylic acid, 5,5'-azobis-5,
The following general formula [VII] such as 5'-dimethyldivaleric acid (Where n represents an integer of 0 or more), and 4,4'-azobis-dibenzoic acid, 5,5'-azobis-diphenylacetylic acid, 6,6'-azobis-diacid The following general formula [VIII] such as phenylpropionic acid (Where n represents an integer of 0 or more).

Acid chloridation of these azo compounds having a carboxyl group is performed using phosphorus pentachloride or thionyl chloride.
It is carried out in dehydrated benzene at 0 ° C. to room temperature. When the generated acid chloride azo compound is added to the solution of the anionic polymer, it is necessary to sufficiently purify the polymer terminal so that the terminal of the polymer is not deactivated by impurities in the azo compound. Although the azo compound is relatively stable to moisture, it needs to be performed in an atmosphere without moisture in a purification process such as recrystallization. Drying of the purified azo compound is preferably performed under reduced pressure using a dehydrating agent such as phosphorus pentoxide. The azo compound is added to the polymer solution in a solution state. Therefore, the solvent must be sufficiently degassed and dehydrated like the polymerization solvent. Dehydration purification of the solvent, dehydration with calcium hydride,
After the distillation, it is preferable to use a product obtained by dehydrating again using an alkali metal such as metallic sodium and distilling.

When adding the azo compound solution to the polymer solution, the temperature of the reaction solution is not particularly limited as long as the azo compound does not thermally decompose. The solvent of the azo compound is limited in terms of solubility in the solvent used, but it is preferable to use the same solvent as used in the production of the polymer as much as possible. The reaction temperature is preferably as low as possible, and is preferably from -70 ° C to 0 ° C. Even if the addition of the azo compound solution is performed gradually,
It may be added all at once. After the addition, the time until the reaction is completely completed varies depending on the polymerization conditions and needs to be set appropriately. However, it can be considered that the reaction is usually completed in 1 to 2 hours. After completion of the reaction, the polymer solution is poured into a large amount of a benzene / methanol mixed solution to isolate the polymer. Reprecipitation purification is preferably performed several times so that unreacted azo compound does not remain in the isolated polymer. The purified polymer is dried by freeze-drying.

[Effect of the Invention] According to the present invention, a novel polymer containing an azo group having a narrow molecular weight distribution and a high yield can be provided.

[Examples] Hereinafter, the present invention will be described in detail with reference to Examples, but this does not limit the present invention in any way.

In addition, the analysis of the polymer of this invention was performed by the following models and measurement conditions.

(1) GPC Tosoh Corp. TSK CP-8000 Column: G4000Hx G2000HXL Solvent: THF Flow rate: 1.0 ml / min. Pressure: 62 kg / cm ² Temperature: 25 ° C Detector: UV-8000 (2) IR JASCO IR-810 KBr method (3) Elemental analysis N2 content (Kjeldahl method) C, N content Yanagimoto Seisakusho Elemental analyzer MT-3 Reference example 1 250 mL of 4,4'-azobis-4-cyanovaleric acid After dissolving in dehydrated benzene and cooling with ice, 5
0.0 g of phosphorus pentachloride was added. After reacting at 0 ° C. for 5 minutes under stirring, the reaction temperature was raised to room temperature. The reaction was performed for 1 hour in this state. After the reaction solution was filtered under nitriding to remove unreacted substances, benzene was removed from the filtrate by distillation under reduced pressure. The obtained solid was washed three times with 100 ml of anhydrous ether / hexane (1/3 by volume) under nitrogen, and then filtered.
The filtrate was dissolved in dehydrated methylene chloride, the solution was poured into anhydrous hexane, and the precipitate was filtered again. The obtained filtrate was recrystallized from anhydrous methylene chloride and dried over phosphorus pentoxide under reduced pressure to obtain 25.4 g (yield 90%) of 4,4-azobis-4.
-Cyanovaleryl chloride was obtained.

UV 242.0, 349.2 nm, mp 93.0 ° C. Example 1 A stirring bar was placed in a 500 ml round bottom flask equipped with a three-way cock, degassed, and then heated and dried. Next, 300 ml of anhydrous tetrahydrofuran and 21.42 g of styrene monomer were charged into the flask using a vacuum line. The reaction solution was cooled at -78 ° C with dry ice methanol and stirred for 30 minutes. After performing nitrogen replacement and deaeration three times, 0.16 mole
6.4 ml of a hexane solution of n-butyllithium at a concentration of / l was added to initiate polymerization. After 10 minutes, withdraw 1 ml of the reaction solution,
Immediately thereafter, 10 ml of a tetrahydrofuran solution containing 0.325 g of azobiscyanovaleryl chloride synthesized in Reference Example 1 was added all at once. Immediately after the addition, the color of polymethylstyryllithium disappeared. After 10 minutes from the addition, the cooling of the reactor was stopped, the reaction temperature was gradually raised to room temperature, and the coupling reaction was performed for 20 hours. After completion of the reaction, the content was poured into a large amount of methanol to isolate a polymer. The obtained polymer was purified twice by reprecipitation with a benzene / methanol system, and then freeze-dried using benzene to obtain 21.0 g (yield 98%) of the polymer. The number average molecular weight (n) and weight average molecular weight (w) of the obtained polymer are 40,000 and 54,600 (dispersion degree Q = 1.37).
Met. On the other hand, n and w of the sampled polymer before coupling were 21,000 and 22,000, respectively.
(Dispersion degree Q = 1.05). The molecular weight after the reaction was about twice, indicating that a quantitative coupling reaction had occurred. The purified polymer was subjected to elemental analysis to obtain the following results.

Elemental analysis value (theoretical value in parentheses) C 92.0% (92.16) H 7.6% (7.71) N 0.1% (0.13) The polymer obtained from the above results has the following structure with one azo group per molecule. It is presumed to be a polymer consisting of

Example 2 Polymerization was carried out using the same polymerization initiator and azo compound as in Example 1 and changing the monomer to α-methylstyrene in the same experimental procedure. A stirring bar was placed in a 500 ml round bottom flask equipped with a three-way cock, degassed, and dried by heating. Next, 300 ml of anhydrous tetrahydrofuran was added to the flask,
And 24.29 g of α-methylstyrene monomer were charged using a vacuum line. The reaction solution was cooled to -78 ° C with dry ice methanol and stirred for 30 minutes. After performing nitrogen replacement and deaeration three times, 6.4 ml of a 0.16 mol / liter n-butyllithium hexane solution was added to initiate polymerization. Ten minutes later, 1 ml of the reaction solution was withdrawn, and immediately thereafter, 10 ml of a solution of 0.325 g of azobiscyanovaleryl chloride in tetrahydrofuran was added all at once. Immediately after the addition, the color of poly-α-methylstyryllithium disappeared. 10 minutes after the addition, the cooling of the reactor was stopped, and the reaction temperature was gradually raised to room temperature.
The coupling reaction was performed for a time. After the completion of the reaction, a large amount of methanol was poured into the content, and the polymer was isolated. The obtained polymer was purified twice by reprecipitation in a benzene / methanol system, and then freeze-dried using benzene to obtain 24.0 g (yield 99%) of the polymer. The number average molecular weight (n) and weight average molecular weight (w) of the obtained polymer are 47,0
00 and 64,400 (dispersion degree Q = 1.37). On the other hand, the sampled polymer before coupling n, and
w was 23,000 and 24,300 (dispersion degree Q = 1.06). The molecular weight after the reaction was about twice, indicating that a quantitative coupling reaction had occurred.

The purified polymer was subjected to elemental analysis to obtain the following results.

Elemental analysis values (theoretical values in parentheses) C 91.3% (91.08) H 8.3% (8.47) N 0.1% (0.12) The polymer obtained from the above results has the following structure having one azo group per molecule. It is presumed to be a polymer consisting of

Example 3 Polymerization was carried out using the same polymerization initiator and azo compound as in Example 1 and changing the monomer to p-methoxystyrene in the same experimental procedure. 500ml with 3-way cock
A stirrer was placed in the round bottom flask of No. 1, and after degassing, it was dried by heating. Next, 300 ml of anhydrous tetrahydrofuran and 10.0 g of p-methoxystyrene monomer were charged into the flask using a vacuum line. The reaction solution was cooled to -78 ° C with dry ice methanol and stirred for 30 minutes. After performing nitrogen replacement and deaeration three times, 4.66 ml of a 0.16 mole / l n-butyllithium hexane solution was added to initiate polymerization. 1 ml of the reaction solution was withdrawn in 10 minutes, and immediately thereafter, a solution of 0.236 g of azobiscyanovaleryl chloride in 10 ml of tetrahydrofuran was added all at once. Immediately after the addition, the color of poly-α-methylstyryllithium disappeared. 10 minutes after the addition, the cooling of the reactor was stopped, and the reaction temperature was gradually raised to room temperature.
The coupling reaction was performed for a time. After completion of the reaction, the content was poured into a large amount of methanol to isolate a polymer. The obtained polymer was purified twice by reprecipitation in a benzene / methanol system, and then freeze-dried using benzene to give 9.80 g (yield 9).
8%) of a polymer. The number average molecular weight (n) and weight average molecular weight (w) of the obtained polymer were 27,000, and
35,100 (dispersion degree Q = 1.3). On the other hand, n and w of the sampled polymer before coupling were 13,0
00 and 14300 (dispersion degree Q = 1.1). The molecular weight after the reaction was about twice, indicating that a quantitative coupling reaction had occurred. The purified polymer was subjected to elemental analysis to obtain the following results.

Elemental analysis values (theoretical values in parentheses) C 91.0% (91.15) H 8.6% (8.48) N 0.2% (0.25) The polymer obtained from the above results has the following structure having one azo group per molecule. It is presumed to be a polymer consisting of

Example 4 Polymerization was carried out using the same polymerization initiator as in Example 1 and changing the monomer to p-methylstyrene in the same experimental procedure. In a 500 ml round bottom flask equipped with a three-way cock,
A stirrer was put in, and deaeration and heat drying were performed. Next, 300 ml of anhydrous tetrahydrofuran and 15.0 g of p-methylstyrene monomer were charged into the flask using a vacuum line. The reaction solution was cooled to -78 ° C with dry ice methanol and stirred for 30 minutes. After performing nitrogen replacement and deaeration three times, 8.8 ml of a 0.16 mole / l n-butyllithium hexane solution was added to initiate polymerization. Ten minutes later, 1 ml of the reaction solution was withdrawn, and immediately thereafter, 10 ml of a tetrahydrofuran solution containing 0.447 g of azobiscyanovaleryl chloride was added. Immediately after the addition, the color of poly-p-methylstyryllithium disappeared. Ten minutes after the addition, the cooling of the reactor was stopped, the reaction temperature was gradually raised to room temperature, and the coupling reaction was performed for 2 hours. After completion of the reaction, the content was poured into a large amount of methanol to isolate a polymer. The obtained polymer was purified twice by reprecipitation in a benzene / methanol system, then again made into a benzene solution, and freeze-dried to obtain 14.9 g (yield: 99%) of the polymer. The number average molecular weight (n) and polymerization average molecular weight (w) of the obtained polymer were 21,000 and 26,200 (dispersion degree Q =
1.25). On the other hand, n and w of the sampled polymer before coupling were 10,000 and 11,000 (dispersion degree Q = 1.1). The molecular weight after the reaction was about twice, indicating that a quantitative coupling reaction had occurred. The purified polymer was subjected to elemental analysis to obtain the following results.

Elemental analysis values (theoretical values in parentheses) C 89.8% (90.94) H 9.9% (9.98) N 0.2% (0.27) The polymer obtained from the above results has the following structure having one azo group per molecule. It is presumed to be a polymer consisting of

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows infrared absorption-difference spectra of the azo group-containing polystyrene obtained in Example 1 and polystyrene. The azo group-containing polystyrene has a nitrile group (-C =) of the azobiscyanovaleric acid residue as a coupling agent.
N) is present in the polymer.

Claims (2)

(57) [Claims] 1. The following general formula [I] (Where R ¹ is an alkyl group or an aryl group, R ² and R ³ are an alkyl group or an aryl group having 1 to 18 carbon atoms, and R ⁴ is a methylene group or an arylene group having 1 to 18 carbon atoms) Wherein R ⁵ and R ⁶ represent an alkyl group or an alkoxy group having 1 to 4 carbon atoms, m represents a degree of polymerization, and represents a positive integer. Group with a molecular weight of 5,000
100100,000 and a molecular weight dispersity (w / n) of 1.01
A polymer that is ~ 1.50. 2. A general formula [II] ClC (O) -R 4 -N = N-R 4 -C (O) Cl [II] ( wherein a methylene group of R ⁴ is from 1 to 18 carbon atoms , An arylene group or an organic group containing a methylene group), and an azo compound represented by the following general formula [III] (Where R ² and R ³ represent an alkyl group or an aryl group having 1 to 18 carbon atoms, and R ⁵ and R ⁶ represent an alkyl group or an alkoxy group having 1 to 4 carbon atoms) The following is obtained by polymerizing the monomer using a polymerization initiator represented by the following general formula [IV] R ¹ -Li [IV] (where R ¹ represents an alkyl group or an aryl group). General formula [V] (Where R ¹ is an alkyl group or an aryl group, R ² and R ³ are an alkyl group having 1 to 18 carbon atoms or an aryl group, and R ⁵ and R ⁶ are an alkyl group having 1 to 4 carbon atoms. Or m represents the degree of polymerization, m represents a positive integer), has a molecular weight of 2,500 to 50,000, and has a dispersity (w / n) of 1.01 to 1,30. The method for producing a polymer according to claim 1, which is obtained by reacting with a polymer.