JPH01108201A - Production of polymer utilizing bissiloxane polymerization initiator - Google Patents

Abstract

PURPOSE: To easily obtain the homopolymer or triblock type polymer of α,β- substd. monomers by bringing these monomers into polymn. reaction by using a specific bis(siloxane) deriv. as a polymn. initiator in the presence of a catalyst and solvent.

CONSTITUTION: (A) A prescribed number of the α,β-unbsatd. monomers (e.g. methyl-, butyl-, allyl methacrylate, acrylonitrile) selected from methacrylate based monomers are brought into polymn. reaction in the presence of (B) the catalyst, such as tris(dimethylamino)sulfonium bifluoride and (C) the solvent, such as tetrahydrofuran or acetonitrile, by using the bis(siloxane) deriv. of the formula (R, R' are each CH₃, C₂H₅, C₃H₇, i-C₃H₇, n-C₄H₉, i-C₄H₉, tetiary butyl, pentyl, 2- or 3-methyl butyl; (n) is 0 to 2) as the polymn. initiator, by which the homopolymer or triblock type polymer of the component A is obtd.

COPYRIGHT: (C)1989,JPO

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a production method for polymerizing α,β-unsaturated hydrocarbon compounds using a bissiloxane polymerization initiator in a group transfer polymerization step. .

[Prior art and problems to be solved by the invention]

Generally, one group transfer polymerization
Polymerization (hereinafter referred to as GTP) process is described in the Journal of the American Chemical Society (polymer prepr.
int, An+, chem, soc,, 27(I), 1
81 (I98B)), it is a recently known polymerization method, briefly described, in which the monomer is a reactive ketenesilylacecool group (ketenesilylacecure group).
“Growing polymer terminals” (a grovl
ngpolyIler chain end). This is referred to as GTP because during the addition reaction, the ketene silyl acecul group can continue polymerization by imparting a new ketene silyl acecul functional group to the newly added monomer. Also, the journal 1
As described on page 65, in the polymerization of α,β-unsaturated esters, amides, and nitriles, a polymerization initiator of ketene silyl acecures and several Lewis acids or anionic compounds are used. This paper introduces a polymerization method related to GTP in the presence of a catalyst such as For example, the GTP-mediated polymerization process of methyl methacrylate (MMA) monomer is depicted in formula (I), where the initiator used is a ketene silyl acetal of β-methyl group, and the catalyst is a soluble biflulide. Say. GTP polymerization is rapidly “alive” at room temperature
(living) produce a polymer and reveal a new structure.

As described later, the monomer used in formula (I) GTP is preferably a methacrylic monomer. However, since the active hydrogen compound interferes with the GTP process, if the active hydrogen compound exceeds the initiator concentration, the growth of the polymer chain will be stopped. Therefore, active hydrogen compounds such as methacrylic acid or hydroxyethyl methacrylate cannot be directly polymerized. However, a bypass is available by utilizing masking groups that can be removed after the desired polymer has been formed. For example, the hydroxy group in question can be derived by using the monomer 2-(trimethylsilyloxy)ethyl methacrylate.

M3 Acrylic monomers other than methacrylates can also be used to produce copolymers, but the polymer chains do not remain in the living chain for a long time.In other words, acrylates are faster than methacrylates. This is because it polymerizes at a high rate, and
In the polymerization of a polymer containing these two types of monomers at the same time, when the initiation reaction is started, only the acrylate is polymerized, as shown in formula (2), and the methacrylate group in question is contained. Becomes a non-crosslinked polymer. This is GT
This is an example in which the structure of a polymer can be controlled by selecting P.

In the formula (2, CH3 GTP), the monomer polymerization conditions require the absence of active hydrogen compounds, all chemicals and solvents used should be pure as well as anhydrous, and the polymerization should be carried out in a dry state. It should be done in

However, oxygen is not blocked. Typical solvents utilized for GTP are toluene, tetrahydrofuran (THF), 1,2-dimethoxyethane, acetonitrile, and N,N-dimethylformamide (DMF) for the nucleophilic catalyst.
) etc. or toluene for Lewis acid catalysts,
1,2-dichloroethane, dichloromethane, etc. must be used. The reaction temperature is preferably from -100°C to 150°C, preferably from 0 to 50°C. However, in order to polymerize acrylates, the temperature is preferably 0°C or lower.

Since polymerization is generally extremely fast, the reaction rate can be adjusted depending on the amount of monomer added during the polymerization.

The induction period of several polymerization initiators and catalysts has been noted, for example trimethylsilyl cyanide. Among the polymerization initiators known to date, 1-alkoxy-1-(trimethylsyloxy)-2-methyl-1-alkenes have been introduced as the most suitable initiators for GTP.

The more alkyl groups there are in silicon (bul
ky) The polymerization rate is lower and the -OR group is placed at one end of each polymer chain to maintain functionality.

As shown in formula (3), since α-silyl esters can be substituted with ketene acetals, they can also be used as GTP polymerization initiators.

In addition, several silyl derivatives added to methacrylate, such as trimethylsilyl cyanide or trimethylsilyl methyl sulfide, also generate ketene acetal, and thus serve as a polymerization initiator as shown in formula (4). Trimethylsilyl cyanide can be produced from ammonium cyanide (R2H''CN-) and trimethylchlorosilicon ((CH3)3SiC1).

It is also said that a polymer in which phosphorus is located at the end of the polymer can be produced using a ketene silyl acetal containing phosphorus as shown in formula (5), and a phosphorus-containing polymerization initiator is described in the literature ( Synthesis, 1982゜497:198
2.915) introduces its manufacturing method.

Formula (5) GTP requires a catalyst in addition to an initiator, including nucleophilic catalysts such as soluble fluoride, bifluride, azide, and cyanide. An easily produced and effective catalyst is tris(dimethylamino)sulfonium (TAS) bifluride, which is crystalline and highly soluble in organic solvents.

Electrophilic catalysts such as zinc halides, alkyl aluminum chlorides, and alkylaluminum oxides are also described in specialized journals (J, Am, CheIw, S
oc,.

105, 5706, 1983). However, the nucleophilic catalyst has more G than the electrophilic catalyst.
This is even more advantageous in the TP process because, based on the initiator, nucleophilic catalysts require 0.1%, while electrophilic catalysts require 10% based on monomers. This is for the purpose of

The molecular weight of the polymer produced by the GTP method is determined as shown in formula (6) depending on the ratio of initiator to monomer.

DP-monomer/initiator Formula (6) The molecular weight can be precisely adjusted in the range 1,000-2,000. However, it is difficult to obtain a high molecular weight polymer. The reason is that the amount is too small for an initiator with only a high molecular weight, so it is maintained at an impurity level. On the other hand, if all the monomers, solvents, catalysts, and initiators are extremely pure, it will cost 100,000-200,000.
Molecular weight polymers can also be produced.

If the rate of the initiator is too high for the chain transfer reaction (propaga-
tion), all polymer chains will be produced simultaneously and the polymer will have a narrow molecular weight distribution. In other words, the degree of mass dispersion (po
lydispersity) approaches 1 as shown in equation (7).

n When homologous series such as methacrylates or acrylates are polymerized by common conventional methods, disordered, random-type copolymers are obtained. However, when acrylic monomers such as acrylonitrile, methacrylate, acrylate, and methacrylate are polymerized using the GTP polymerization method, random copolymers are generated (Macromolecules
, 17.1417.1984).

On the other hand, all G
When polymerized by the TP method, a block type polymer can be easily produced, and when the initially added monomer is completely exhausted, a new monomer can be added.

For example, when attempting to produce an AB type block polymer of methacrylate and acrylate, the block polymer is produced by adding the less reactive methacrylate first and then adding the acrylate monomer and polymerizing it. be able to. This order of addition is such that, as shown in equation (8), the terminal group of the dialkyl ketene silyl acecure of the methacrylate is more active in the initiation reaction than the terminal group of the monoalkyl ketene of the "living" acrylate monomer. This is because it is tinged with So, after the methacrylate polymerization is complete, adding the acrylate monomer causes all polymer chains to grow simultaneously. If the order is reversed, higher molecular weight polymers will be polymerized due to higher reactivity.

Formula (8) The "living" polymer thus produced as an intermediate has the following properties as shown in U.S. Pat. No. 4,508,880:
Addition of water or an active hydrogen compound such as an alcohol such as methanol converts the final product to a "non-living" (non-living) polymer as shown in formula (9).

Formula (9) Above, we have explained the GTP polymerization process in which groups are transferred when an α,β-unsaturated hydrocarbon is polymerized using a ketene silyl acetal derivative known to date as an initiator. To describe several advantages that can be predicted by using such an initiator, unlike general polymerization, it is possible to obtain a polymer with a narrow molecular weight distribution. properties and can produce a "living" intermediate during copolymerization.
produced into a living'' intermediate and then a more active jli
Since the ffi form can be added and polymerized, it is possible to prevent the production of random copolymers. Also, when a "living" intermediate is charged with 5 active hydrogen compounds, it "lives" for a certain period of time.
Since it can be kept alive, it can be used again at any desired time.

Known reaction initiators used for GTP are U.S. Pat.
As disclosed in No. 17,034 and No. 4,508,880, it mainly consists of ketene silyl acecures containing double bonds in alpha and beta. Therefore, as described above, monomers such as acrylates, methacrylates, and acrylonitrile can be polymerized or copolymerized using the GTP method.

However, when attempting to polymerize a triblock type copolymer of ABC, after forming the A component into a living polymer with the desired molecular weight, the B component is added and polymerized to the "living" A1 polymer. Polymerized with AB acid component block
Producing a living “AB block type polymer,” and finally,
Component C is produced by reacting AB block type polymers to produce an ABC triblock type copolymer, so the disadvantage is that the reaction steps are complicated.

[Purpose and outline of the invention]

Thus, the purpose of the present invention is to provide a method for easily producing a triblock copolymer or a homopolymer using the GTP method, and according to research experiments conducted by the present inventors, the general formula ( It has been found that the object can be achieved by using the bissiloxane derivative represented by I) as a reaction initiator.

[Detailed description of the invention]

Therefore, the present invention uses the following general formula (I) to represent α.

A method for producing a homopolymer or triblock type polymer of β-unsaturated monomers is provided.

In the general formula (I), R is a linear or side chain aliphatic hydrocarbon, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, pentyl, 2-
Represents an aliphatic hydrocarbon group having 5 or less carbon atoms such as methylbutyl and 3-methylbutyl. Preferably, the carbon number is 4 or less.

R' is the same as R, and n is an integer from 0 to 2.

In the present invention, α,
The β-unsaturated monomers are polymerized to produce homopolymers or triblock copolymers.

Examples of the catalyst used in the present invention include tris(dimethylamino)sulfonium bifluoride (TASHF2),
Tris(dimethylamino)sulfonium difluorotrimethylsiliconate (TASF), potassium bifluoride (KHF2), etc. can be mentioned, and as the solvent, for example, tetrahydrofuran (THF), acetonitrile, etc. are preferably used.

Examples of α,β-unsaturated monomers used in the present invention include methacrylate, methyl methacrylate, butyl methacrylate, and allyl methacrylate (alylmcthac-rylatc) when producing a homopolymer.
), acrylonitrile, etc. In addition, when making a triblock type copolymer, butyl methacrylate, methyl methacrylate and butyl methacrylate,
Methacrylate and methyl methacrylate and methacrylate, allyl methacrylate and methyl methacrylate and allyl methacrylate, acrylonitrile and methyl methacrylate and acrylonitrile, methyl methacrylate and butyl methacrylate and methyl methacrylate, methyl methacrylate and allyl methacrylate and selected from among the combinations of methyl methacrylate.

In the present invention, a bissiloxane derivative of general formula (I) is used as a polymerization initiator when such an α,β-unsaturated monomer is polymerized in the GTP process, and as such a bissiloxane polymerization initiator, There are three types: [1
, 6-Simethoxy2,5-dimethyl-1,5-hexadiene-1゜6-diylbis(oxy)]bis(trimethylsilane) (hereinafter referred to as polymerization initiator A), [1゜5-dimethoxy-2 , 4-dimethyl-1,4-pentadiene-1,5-diylbis(oxy)]bis[trimethylsilane] (hereinafter referred to as polymerization initiator B), and [
1,4-dimethoxy-2,3-dimethyl-1,3-butadiene-1,4-diylbis(oxy)]bis(trimethylsilane) (hereinafter referred to as polymerization initiator C) is particularly effective.

As described above, the production of polymers according to the present invention, particularly the production of triblock copolymers according to the present invention, has various advantages over known production methods. - For example, because they have functional groups on both sides, triblock-type polymers can be created by simultaneously producing two monomers into a "living" polymer and then adding the remaining monomers at the end. Since a polymer can be produced, the polymerization process can be simplified and the molecular weight distribution can be maintained constant.

Incidentally, the polymerization initiator used in the present invention can be produced as follows. That is, publicly known materials (Maeromo
lecules, 20(7), 1473 (I987
)), secondary amines of general formula (n) can be prepared using tetrahydrofuran (TH
F) Adding butyllithium under a solvent and nitrogen gas atmosphere,
When the reaction is carried out at a low temperature below the freezing point, lithium diisoalkylamide (LDA) of general formula (III) is obtained.

(In) (m) In the general formula (m), R represents an aliphatic alkyl group such as ethyl, propyl, isopropyl, n-butyl, isobutyl and tertiary butyl. - In the general formula (m), R is the general formula (I
It is the same as R in I).

The obtained LDA was converted to general formula (IV) at -90°C to 40°C.
By adding the diester and trialkylchlorosilicon of general formula (V), stirring, and raising the temperature to room temperature to react, a new bissiloxane derivative for use in the present invention represented by general formula (I) can be obtained. .

In general formula (IV), R and n are the same as R and n in general formula (I). In general formula (V), R represents a methyl or ethyl group.

〔Example〕

Hereinafter, embodiments according to the present invention will be described in detail, but the present invention is not limited to these embodiments unless it departs from the scope of the claims. Incidentally, an example of a method for producing a bissiloxane derivative used as a polymerization initiator in the present invention will first be given as a reference example.

Reference Example 1 Production of [1,6-simethoxy2,5-dimethyl-1゜5-hexadiene-1,6-diylbis(oxy)]bis(trimethylsilane) (polymerization initiator A) 1501 in 30 flasks with a capacity of 10100O of THF was added, a nitrogen gas atmosphere was added, 0.2n+ol of diisopropylamine was added, and the temperature was maintained at -30°C.
2.5o+ol of n-butyllithium was gradually added and stirred to obtain lithium diisobutylamide (LDA). After cooling the LDA to -90°C. 1 mol
of dimethyl-2,5-dimethylamylate and 0.5 mo
1 of trimethylchlorosilane was gradually added and the temperature was increased to 25
After raising the temperature to 0.degree. C., the lithium chloride was filtered off.

Filter the remaining solution under reduced pressure (0, 1 mmHg.

When distilled at 84° C.), polymerization initiator (A) was obtained with a yield of 30%. The confirmation is as follows.

H-NMR (CD C13) (ppm): 0.2
(s, 18H), 1, 6 (s, 6H), 2. 0 (s, 4
H), 3.7 (s, 6H) 'C-NMR (CDC13) (ppll): 0 (
I), 15 (5), 30 (4), 57 (2)
, 96 (3) , 150 (6) Reference Example 2 [1,5-dimethoxy-2,4-dimethyl-1°4-pentadiene-1,5-diylbis(oxy)] Bis[
Production of Trimethylsilane (Polymerization Initiator B) All conditions were the same as in Reference Example 1. However, instead of dimethyl-2,5-dimethyl adipate, dimethyl-2,4-dimethylglutamate was added as a polymerization initiator (
B) was obtained. The confirmation is as follows.

H-NMR (CDCl3) (I) pI): 0.6
(s, 18H), 1.9 (s, 6H), 3.0 (s, 2H), 4-
0 (s, 6H) 13C-NMR (CDCl 3) (I)I)o+)
'0 (I), 13 (5), 31 (4), 57
(2), 94 (3), 151 (6) Reference Example 3 [1,4-dimethoxy-2,3-dimethyl-1°3-butadiene-1,4-diylbis(oxy)bis(trimethylsilane) (polymerized Production of initiator C) LDA was produced in the same manner as in Reference Example 1, cooled to -75°C, and then mixed with O.1 mol of dimethyl-2,4-dimethylsuccinate and O. After gradually adding 5n+ol of trimethylchlorosilane and raising the temperature to 30°C, it was filtered. Filter the remaining solution under reduced pressure (0.1 mm 1 g, 84
When distilled at ℃), the yield of polymerization initiator (C) was 75%.
was gotten. The confirmation is as follows.

IH-NMR (CDC13, δ): 0, 2 (s, 18H, (CH3)3 S i -), 1.7 (s, 6H.

CH3), 3.6 (s, 6H.

'-OCH3) 13C-NMR (CDC13) (ppm): 150
(I), 97 (2), 5g (3), 30 (4
), 0 (5) Example 1 Production of polymethyl metaflate (PMMA) 0, 35
4i mmol of polymerization initiator A (obtained in Reference Example 1)
After addition to 1 THF, 0,2 noaol TAS
After adding HF2 and stirring for about 20 minutes under an argon atmosphere, 15 μol of methyl methacrylate (MMA) was gradually added using a sealed syringe.

After reacting for about 30 minutes, 3n+1 methanol was added to stop the reaction and the solvent was recovered, quantitatively P M
MA was manufactured.

The following Table 1 shows butyl methacrylate (BMA), allyl methacrylate (A
This is experimental data regarding the polymerization of MA), methacrylate (MA), acrylonitrile (AN) monomers, etc.

Example 2 Triblock copolymer (PBMA-PMMA-PBM
Preparation of A) In THF of 41, 0.33 mmol of polymerization initiator B (obtained in Reference Example 2) and 0.33 mmol of polymerization initiator B (obtained in Reference Example 2) were added. 05I1 mol TASHF
Add 2 and stir in an argon atmosphere for 20 minutes.
7 of MMA was gradually added and reacted for 30 minutes to form an MMA block polymer, and then 7.6 mmol of B was added.
Inject MA with a syringe. The reaction was allowed to proceed again for 1 hour, and as a result of adding 31 methanol to stop the reaction and recovering the solvent, a triblock copolymer composed of PBMA-PMMA-PBMA was produced.

Table 2 below shows the conditions for producing triblock copolymers, which were carried out under similar conditions to the above polymerization.

〔Effect of the invention〕

According to the present invention, a homopolymer or a triblock copolymer of α,β-unsaturated monomers can be easily produced by using a bissiloxane derivative as a polymerization initiator, which is effective.

Applicant's agent: Mr. Sato

Claims (1)

[Claims] 1. A method for producing a polymer using a bissiloxane polymerization initiator of the general formula (I) to produce a homopolymer or triblock type polymer in the presence of a catalyst and a solvent ▲Math. Chemical formulas, tables, etc. are available▼(I) In the general formula (I), R represents a methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tertiary butyl, pentyl, 2-methylbutyl, or 3-methylbutyl group. indicate. R' is the same as R, and R and R' may be the same or different from each other. n is 0 to 2
is an integer up to . 2. The method for producing a polymer using a bissiloxane polymerization initiator according to claim 1, wherein the homopolymer is selected from methacrylate, methyl methacrylate, butyl methacrylate, allyl methacrylate, or acrylonitrile. . 3. As triblock polymers, butyl methacrylate, methyl methacrylate, and butyl methacrylate,
Methacrylate and methyl methacrylate and methacrylate, allyl methacrylate and methyl methacrylate and allyl methacrylate, acrylonitrile and methyl methacrylate and acrylonitrile, methyl methacrylate and butyl methacrylate and methyl methacrylate, methyl methacrylate and allyl methacrylate and 2. A method for producing a polymer using the bissiloxane polymerization initiator according to claim 1, wherein the initiator is selected from methyl methacrylate. 4. The catalyst is selected from tris(dimethylamino)sulfonium bifluoride, tris(dimethylamino)sulfonium difluorotrimethylsiliconate, or potassium bifuromide. A method for producing a polymer using a bissiloxane polymerization initiator. 5. The method for producing a polymer using a bissiloxane polymerization initiator according to claim 1, wherein the solvent is selected from tetrahydrofuran or acetonitrile.