JPH04351610A - Preparation of polymer - Google Patents

Abstract

PURPOSE:To obtain a polymer having regulated molecular weight and molecular weight distribution by anionically polymerizing an aromatic ester compound in the presence of a metallic anionic polymerization catalyst. CONSTITUTION:An aromatic ester compound represented by formula I is anionically polymerized in the presence of a metallic anionic polymerization catalyst to obtain a polymer having a structural unit represented by formula II. In the formulae, R<1> represents H, an alkyl, or an aryl; R<2> represents a 1-6C alkyl; R<3> and R<4> each represents an alkyl or an aryl, provided that the sum of the carbon atoms possessed by R<3> and R<4> is or more; R<5> represents a 1-6C alkyl, a hydroxyalkyl, or an aryl; and m and n each is 0 or 1. Examples of the compound of formula I include 2,6-dimethylphenyl 4-vinylbenzoate and 4- methoxy-2,6-di-t-butylphenyl 4-vinylbenzoate.

Description

[Detailed description of the invention]

The present invention relates to a method for producing aromatic polymers having ester groups. This polymer is useful as a modifier and compatibilizer for resins such as polystyrene, ABS, polyphenylene ether, and SAN.

Furthermore, since ester groups can be easily converted into carboxylic acids, they are effective in improving the printability and adhesion of these resins.

0003

[Prior Art] As a polymer of a styrene derivative having a functional group, there is a method in which a polymer with a controlled molecular weight and molecular weight distribution is synthesized by anionic polymerization after protecting functional groups such as a hydroxyl group, an amino group, or a formyl group. known (S.
Nakahama, A. Hirao, Prog. Pol
ym. Sci. , 15, 299 (1990), T. Is
hizone, R. Kato, Y. Ishino, A.
Hirao, S. Nakahama, Macromol
ecules, 24, No. 7, 1449 (1991)
).

It is also known that a similar method is applied to aromatic monomers having ester groups (T. Ishiz
one, A. Hirao, S. Nakahama, Ma
cromolecules, 22, 2895, (198
9)). However, in the above method, 4-vinylbenzoic acid (t-butyl) is used as an aromatic monomer having an ester group, but it is difficult to obtain a polymer with sufficiently controlled molecular weight and molecular weight distribution. The polymerization temperature requires a low temperature of -95°C or lower, and there is a problem that polymerization progresses when the counter cation during anionic polymerization is K+, but not when Li+ is used. It's hard to say.

[0005]

SUMMARY OF THE INVENTION The present invention provides a method for producing a polymer or copolymer with controlled molecular weight and molecular weight distribution by using a specific ester compound as a monomer pair. Take it as a challenge.

[0006]

[Means for Solving the Problems] The present inventors anionically polymerized an aromatic ester compound represented by the following general formula (I) in the presence of a metal-containing anionic polymerization catalyst to obtain the general formula (
II) A method for producing a polymer having the structural unit shown in the following is provided.

[0007]

[Chemical formula 3]

[In the formula, R1 is a hydrogen atom, an alkyl group or an aryl group; R2 is an alkyl group having 1 to 6 carbon atoms; R3 and R4 are each independently an alkyl group or an aryl group, The sum of the carbon numbers of R3 and R4 is 2 or more; R5 is an alkyl group having 1 to 6 carbon atoms,
is an oxyalkyl group or an aryl group; m and n are 0
or an integer of 1. ]

[0009]

[C4]

[In the formula, R1, R2, R3, R4
, R5, m and n are the same as in formula (I). ] (Polymerizable aromatic ester compound) Examples of the aromatic ester compound represented by the general formula (I) include 4-vinylbenzoic acid (2,6-dimethylphenyl), 4-vinylbenzoic acid (2,6-dimethylphenyl), and 4-vinylbenzoic acid (2,6-dimethylphenyl). -diisopropylphenyl), 4-vinylbenzoic acid (4-methyl-2,6-di-t-butylphenyl), 4-vinylbenzoic acid (4-methoxy-2,6-
di-t-butylphenyl), etc.

Up to 90 mol% of this monomer, preferably 5 to 85 mol%, can be replaced by other anionic polymerizable monomers.

Examples of such anionically polymerizable monomers include styrene, α-methylstyrene, (o,m,p)-
Methylstyrene, (o,m,p)-chlorostyrene, (
m,p)-divinylbenzene, (m,p)-diisopropenylbenzene, (m,p)-vinylisopropenylbenzene, vinylnaphthalene, acenaphthalene, butadiene, isoprene, 2,3-dimethylbutadiene, 1,3
-Pentadiene, 2-cyanobutadiene, 2-chlorobutadiene, 2-phenylbutadiene, vinyl chloride, vinylidene chloride, acrylonitrile, α-methacrylonitrile, α-ethacrylonitrile, α-octylacrylonitrile, N,N-dimethylacrylamide, N,N-dioctyl acrylamide, N-methyl-N
-ethyl acrylamide, methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, 2-methylhexyl acrylate, octyl acrylate, methyl methacrylate, methyl ethacrylate, ethyl methacrylate, phenyl methacrylate, 2-vinylpyridine, 4-vinylpyridine, ethyl Vinyl ketone, t-butylvinylketone, N-vinylcarbazole, trimethoxyvinylsilane, triethoxyvinylsilane, tri2-methoxyethoxysilane, triacetoxyvinylsilane, trimethylvinylsilane,
Tributylvinylsilane, dimethyldivinylsilane, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, hexaphenylcyclotrisiloxane, octaphenylcyclotetrasiloxane, 2,4,
6-trimethyl-2,4,6-triphenylcyclotrisiloxane, trimethyltriethylcyclotrisiloxane, tetramethyltetraethylcyclotrisiloxane,
Trimethyltrivinylcyclotrisiloxane, ethyl isocyanate, propyl isocyanate, n-butyl isocyanate, isobutyl isocyanate, amyl isocyanate, hexyl isocyanate, octadecyl isocyanate, phenyl isocyanate, benzyl isocyanate, allyl isocyanate, tolyl isocyanate, p-methoxyphenylisocyanate, ethylene oxide, Propylene oxide, 1,2-epoxybutane, 1,2-epoxyhexane, 1,2-epoxyoctane, 2-phenyl-1,2-epoxyethane, 4-phenyl-1,2-epoxybutane, ε-caprolactone and δ - These anionic polymerizable monomers, which are valerolactone, can be used alone or in combination or sequentially in two or more components. That is, the living polymer may be a single, random or block polymer chain.

(Polymerization) The aromatic monomer having an ester group represented by the general formula (I) is anionically polymerized in the presence of a metal-containing polymerization initiator to obtain a living polymer. As the metal-containing polymerization initiator, for example, n
-butyllithium, sec-butyllithium, tert
-Butyl lithium, ethyl lithium, benzyl potassium, cumyl potassium, K-naphthalene, α-methylstyrene tetramer dianion -Na, Na-naphthalene, Na-
Examples include biphenyl and Na-anthracene.

The anionically polymerizable monomer represented by the general formula (I) is polymerized at a temperature of -100°C to 200°C, preferably -90°C to 180°C, particularly preferably -80°C to 150°C. The reaction can be carried out at room temperature, reduced pressure or increased pressure.

Solvents that can be used in the above polymerization include, for example, n-hexane and n-heptane as aliphatic hydrocarbons, cyclohexane and decahydronaphthalene as alicyclic hydrocarbons, and benzene and toluene as aromatic hydrocarbons. , xylene (o-, m-, p-), teratohydrofuran, dioxane, ethyl ether, pyridine, diglyme, etc. can be used as the aprotic polar solvent. These solvents may be used alone or as a mixture.

(Polymer) The polymer obtained by polymerization is
General formula (II)

[0017]

[C5]

[In the formula, R1, R2, R3, R4
, R5, m and n are the same as in formula (I). ] with a number average molecular weight of 9,000 to 1,000,000 and a molecular weight distribution of 1.04 to 1.
．． It is 3.

[0019]

[Action] By bringing a bulky 2,6-alkyl-substituted aromatic ring near the ester as a vinylbenzoic acid ester, nucleophilic attack by carbanions can be prevented, and aromatic esters of 4-vinylbenzoic acid can be formed by anionic polymerization. Living polymers of the following types can be produced.

[0020]

【Example】

Example 1 (1) Synthesis of 4-vinylbenzoic acid chloride In a 100 ml eggplant flask with N2 substitution, 43 m of thionyl chloride was added.
l (600 mmol), 0.01 g (as a polymerization inhibitor)
0.06 mmol) of tert-butylcatechol was added, and the mixture was cooled with ice water. 4-vinylbenzoic acid 20.
19 g (136 mmol) was added in several portions, and the mixture was stirred for 4 hours while being cooled with ice water. Install Jimroth,
The ice bath was changed to a 40°C oil bath, and the mixture was gently refluxed for about 1 hour until it became a yellowish brown homogeneous system. The reaction product was transferred to a distillation apparatus, thionyl chloride was distilled off under reduced pressure at room temperature, and then heated and distilled under reduced pressure to obtain 20.1% of 4-vinylbenzoic acid chloride.
1g (121 mmol) yield 89%, boiling point 65-67
Obtained at °C/0.1 mmHg. The obtained 4-vinylbenzoic acid chloride was a colorless and transparent liquid, and it was confirmed by GC that it was a substantially pure product.

(2) Synthesis of 4-vinylbenzoic acid (2,6-diisopropylphenyl) In 60 ml of THF, 10 ml (54 mmol) of 2,6-diisopropylphenol and 33 ml of butyllithium solution were added.
ml (53 mmol) were reacted. Next, by adding 8.8 g (53 mmol) of 4-vinylbenzoic acid chloride, 14.5 g (47 mmol) of 4-vinylbenzoic acid (2,6-diisopropylphenyl) was obtained in a yield of 89.
Obtained in %. Melting point: 84.0-84.2°C. The structure is IR,
Confirmed by 1H-NMR, 13C-NMR, and elemental analysis.

(3) Polymerization All polymerizations were carried out under high vacuum using the break-seal method.

First, the inside of the apparatus is cleaned with K-naphthalene (0
．． 250 mmol/5 ml THF solution). Next, K-naphthalene for initiators (0.0878 mmol/5 ml THF solution) and 1,1-diphenylethylene (0.288 mmol/5 ml THF solution) were added and mixed, and reacted at -78°C for 10 minutes with stirring. Ta.

Next, 4-vinylbenzoic acid (2,6-diisopropylphenyl) (1.44 mmol/10 ml)
THF solution) was added at −78° C. and polymerized for 2 hours with sufficient stirring, and then the polymerization solution was added to a large excess of methanol to precipitate the produced polymer. After the polymer was filtered and dried, it was reprecipitated twice with THF-methanol and finally freeze-dried from benzene. The obtained polymer was subjected to GPC
The molecular weight distribution (Mw/Mn) was measured with VPO, and the number average molecular weight (Mn) was measured with VPO. Mw/Mn=1.0
3, Mn=9600, which agreed well with the calculated number average molecular weight of 8400 determined from the ratio of monomer to initiator. The yield was 66%.

From the above, this polymer has the following formula (I
II)

[0026]

[C6]

It is a polymer having the following structural units.

Example 2 In Example 1, the amount of K-naphthalene used was changed to 0.06
13 mmol, the amount of 1,1-diphenylethylene used was changed to 0.338 mmol, the amount of 4-vinylbenzoic acid (2,6-diisopropylphenyl) used was changed to 1.57 mmol, and the polymerization time was changed to 20 hours. The same procedure was carried out to obtain a polymer having a number average molecular weight of 21,000 and a molecular weight distribution of 1.11.

Example 3 In Example 1, instead of K-naphthalene, Li-naphthalene was used in an amount of 0.0751 mmol, 1,1-diphenylethylene was used in an amount of 0.362 mmol, and 4-vinylbenzoic acid (2, A polymer having a molecular weight distribution of 1.08 and a number average molecular weight of 11,000 was produced in the same manner except that the amount of 6-diisopropylphenyl used was changed to 1.65 mmol and the polymerization time was changed to 20 hours.

Example 4 (1) 4-vinylbenzoic acid (4-methyl-2,6-di-
Synthesis of 4-methyl-2,6-di-t-butylphenol (t-butylphenyl) 8.6
25 ml (38.5 mmol) of a butyllithium solution in 1 g (39.1 mmol) of THF followed by 6.11 g (36.7 mmol) of 4-vinylbenzoic acid chloride.
By adding 6.20 g (17.7 mmol)
4-vinylbenzoic acid (4-methyl-2,6-di-t-
butylphenyl) was obtained in a yield of 48%. Melting point 146-1
48℃.

The structure is 1H-NMR, 13C-NMR,
Confirmed by elemental analysis and IR.

(2) In Polymerization Example 1, 0.030 mmol of cumylpotassium was used instead of K-naphthalene, 0.075 mmol of 1,1-diphenylethylene, and 4-vinylbenzoic acid (2,6- The same procedure was repeated except that 1.2 mmol of 4-vinylbenzoic acid (4-methyl-2,6-di-t-butylphenyl) was used instead of (diisopropylphenyl) and the polymerization time was changed to 20 hours, but the number average molecular weight was 13,000. , produced a polymer with a molecular weight distribution of 1.05.

Example 5 The amount of K-naphthalene used was 0.139 mmol, 1.1
-The amount of diphenylethylene used is 0.166 mmol,
4-vinylbenzoic acid (4-methyl-2,6-
A polymer having a number average molecular weight of 13,000 and a molecular weight distribution of 1.12 was produced in the same manner as in Example 1, except that 2.11 mmol of di-t-butylphenyl) and the polymerization time were changed to 20 hours.

Example 6 The amount of K-naphthalene used was 0.108 mmol, 1.1
- The amount of diphenylethylene used is 0.139 mmol,
A number average molecular weight of 24,000 was prepared in the same manner as in Example 5, except that the amount of 4-vinylbenzoic acid (4-methyl-2,6-di-t-butylphenyl) used was changed to 2.73 mmol.
A polymer with a molecular weight distribution of 1.13 was produced.

Example 7 (1) Synthesis of 4-vinylbenzoic acid (2,6-dimethylphenyl) A mechanical stirrer equipped with a Teflon spool was attached to a 300 ml two-necked flask substituted with N2, and THF3
0ml, 2,6-dimethylphenol 11.8g (97
mmol) was added. While cooling the system with ice water, n-butyllithium was added dropwise from the dropping funnel, followed by 16.1 g (97 mmol) of 4-vinylbenzoic acid chloride. A white precipitate of lithium chloride gradually formed in the system, confirming the progress of the reaction. After the dropwise addition was completed, the ice water bath was removed and the mixture was stirred at room temperature overnight. The next day, the reaction solution was washed twice with 2N-HCl, 5
% NaOH aqueous solution twice and H2O three times. The ether solution was dried over MgSO4, concentrated by evaporation, and purified by recrystallization from hexane to yield 22.1 g (81.8 mmol) of 4-vinylbenzoic acid (2,6-dimethylphenyl). The yield was 84%. Melting point: 41.0-41.2°C.

(2) The amount of polymerized K-naphthalene used was 0.0948 mmol, 1,
The amount of 1-diphenylethylene used was 0.187 mmol, 4-vinylbenzoic acid (2,6-dimethylphenyl) was replaced with 1.63 mmol, and the polymerization time was The number average molecular weight was 11 in the same manner as in Example 1 except that the time was changed to 20 hours.
000, a polymer with a molecular weight distribution of 1.12 was produced.

Example 8 In Example 7, 0.0498 mmol of cumylpotassium was used instead of K-naphthalene, 0.0648 mmol of 1,1-diphenylethylene, and 0.0648 mmol of 4-vinylbenzoic acid (2,6-dimethyl phenyl) usage amount to 3.65
The number average molecular weight was 12 in the same manner except that the number was changed to mmol.
000, a polymer with a molecular weight distribution of 1.07 was produced.

Example 9 In Example 7, 0.108 mmol of Li-naphthalene was used instead of K-naphthalene, 0.192 mmol of 1,1-diphenylethylene, and 4-vinylbenzoic acid (2,6 -dimethylphenyl) used in an amount of 2.1
The number average molecular weight was 120 in the same manner except that the number was 6 mmol.
00, a polymer with a molecular weight distribution of 1.10 was produced.

Example 10 In Example 9, 4-vinylbenzoic acid (2,6-dimethylphenyl) was replaced with 4-vinylbenzoic acid (2,6-dimethylphenyl).
-Dimethyl-4-methoxyphenyl) was used in the same manner, but the number average molecular weight was 13,000 and the molecular weight distribution was 1.1.
Polymer No. 2 was produced.

Comparative Example 1 (1) Synthesis of 4-vinylbenzoic acid (2-methylphenyl) A mechanical stirrer with a Teflon spool was attached to a 300 ml two-necked flask substituted with N2, and 30 ml of pyridine and 6.2 ml of o-cresol ( 60 mmol)
, add 60 ml of dehydrated ether. While cooling the system with ice water, add 4-vinylbenzoic acid chloride from the dropping funnel9.
A solution of 30 g (55.9 mmol) diluted with dehydrated ether was added dropwise. A white precipitate of pyridine hydrochloride gradually forms in the system, confirming the progress of the reaction. After the dropwise addition was completed, the ice water bath was removed and the mixture was stirred at room temperature overnight. The next day, the reaction solution was filtered to remove pyridine hydrochloride, and then washed twice with 2N-HCl.
Washed twice with 5% NaOH aqueous solution. M the ether solution
Dry over gSO4, concentrate by evaporation and recrystallize from a small amount of hexane at -30°C. Yield 9.6
g (40.3 mmol) of 4-vinylbenzoic acid (2-methylphenyl) was obtained in a yield of 67%. Melting point 44.8~4
5.2℃.

(2) In Polymerization Example 1, the amount of K-naphthalene used was 0.09
73 mmol, 0.144 mmol of 1,1-diphenylethylene used, 2.58 mmol of 4-vinylbenzoic acid (2-methylphenyl) instead of 4-vinylbenzoic acid (2,6-dimethylphenyl), and polymerization time 2
Polymerization was carried out in the same manner except that the time was changed to 0 hours, but no polymer could be produced.

Comparative Example 2 In Example 1, 0.137 mmol of Li-naphthalene was used instead of K-naphthalene, 0.187 mmol of 1,1-diphenylethylene, and 0.187 mmol of 4-vinylbenzoic acid (2,6 -3.12 mmol of 4-vinylbenzoic acid (phenyl) instead of dimethylphenyl), and the polymerization temperature was changed to -
The same procedure was carried out except that the temperature was 95°C and the polymerization time was 4 hours.
Polymerization did not proceed.

[0043] Polymer yields of these Examples and Comparative Examples,
Table 1 shows the number average molecular weight and molecular weight distribution.

[0044]

[Table 1]

[0045]

[Effect] Since a bulky substituent is used as the ester component of 4-vinylbenzoic acid ester, it becomes possible to prevent nucleophilic attack by carbanions, and it becomes possible to polymerize aromatic esters of 4-vinylbenzoic acid.

Claims (1)

[Claims] Claim 1: An aromatic ester compound represented by the following general formula (I) is anionically polymerized in the presence of a metal-containing anionic polymerization catalyst to produce a polymer having a structural unit represented by the general formula (II). how to. [Formula, R1 is a hydrogen atom, an alkyl group or an aryl group; R2 is an alkyl group having 1 to 6 carbon atoms;
R3 and R4 are each independently an alkyl group or an aryl group, and the sum of the carbon numbers of R3 and R4 is 2 or more; R5 is an alkyl group, oxyalkyl group, or aryl group having 1 to 6 carbon atoms; ; m and n are integers of 0 or 1. ] [Formula 2, R1, R2, R3, R4, R5, m and n are the same as in formula (I). ]