JPH0733405B2 - Method for producing silyl vinyl ether polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing a silyl vinyl ether polymer using an aldehyde as an initiator.

(Prior Art) Conventionally, a method for producing a silyl vinyl ether polymer using an aldehyde as an initiator is known in US Pat. No. 4,544,724. According to this U.S. patent, the catalyst is a compound that is a source of bifluoride ions, such as potassium bifluoride, tetrabutylammonium bifluoride or tris (dimethylamino) sulfonium bifluoride, or a Lewis acid such as zinc iodide. , Zinc bromide, zinc chloride, ether adducts of boron trifluoride or dialkylaluminum halides are shown, with bifluoride ion, zinc bromide, zinc chloride and zinc iodide being the most preferred catalysts, with zinc bromide being most preferred. Is shown. Further, as the solvent, an aprotic solvent that sufficiently disperses or dissolves the monomer, the initiator or the initiator precursor, and the catalyst is shown to be suitable.For example, when a zinc compound is used as the catalyst, toluene or xylene is used. Are limited to aromatic hydrocarbons, aliphatic hydrocarbons or chlorinated hydrocarbons, such as toluene, dichloromethane and 1,2-dichloroethane.

Further, as the silyl vinyl ether, in the monomer represented by the following formula (I), in particular, each R group is alkyl, and the total number of carbon atoms in all R groups is at least 6, and at least 1 It has been shown that it is more preferred that the R group of is a branched alkyl.

CH ₂ ═CH—OSi (R) ₃ (I) (Problems to be solved by the invention) However, in the above-mentioned conventional method for producing a silyl vinyl ether polymer, a bifluoride ion or a Lewis acid is used as a catalyst. Therefore, after completion of the polymerization, it is necessary to wash with water or reprecipitate to remove the dissolved catalyst. In the conventional method, among the monomers represented by the general formula (I), the monomer that is industrially mass-produced and can be obtained at low cost is trimethylsilyl vinyl ether, but this monomer produces only a polymer having a low polymerization yield and a low molecular weight. Therefore, it was necessary to use a monomer having a branched alkyl group such as t-butyldimethylsilyl vinyl ether.

(Means for Solving the Problems) As a result of intensive research on the polymerization of silyl vinyl ether, the present inventor found that the above problems can be solved by using a solid acid as a catalyst, and It came to completion.

Further, as a result of exploring an effective polymerization method, it was found that the use of a solid acid composed of a clay mineral or a heteropoly acid as a catalyst exerts a more excellent effect. That is, the present invention provides a method for producing a polymer of silyl vinyl ether, which comprises using at least one solid acid selected from a clay mineral and a heteropoly acid as a catalyst in the polymerization of silyl vinyl ether using an aldehyde as an initiator. is there.

Among the catalysts used in the present invention, a particularly suitable one is a clay mineral, and preferably contains, for example, montmorillonite, acidic clay clay mica, tetrafluorosilicon mica, talc, zeolite, kaolinite and the like.

The silyl vinyl ether used in the present invention is a monomer represented by the general formula (2) R′CH═CR ″ = OSi (R) ₃ (2), wherein R, R ′ and R ″ are used.
Is a group independently selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an aryl group, an alkaryl group and an aralkyl group. In the present invention, trimethylsilyl vinyl ether, which is industrially mass-produced and inexpensively available, is preferably used as the silyl vinyl ether, and a polymer having a high polymerization yield and a high molecular weight can be obtained.

The aldehyde used as an initiator in the present invention is
There is no particular limitation as long as it has an aldehyde group, and examples thereof include aliphatic aldehydes, aromatic aldehydes, polymer aldehydes, and the like, and specifically, acetaldehyde, isobutyraldehyde, 3- (dimethylamino) propionaldehyde, 3,3 ′. , 3 ″ − (1,3,5-benzenetriyl)
Tris (propionaldehyde), benzaldehyde,
These include terephthal aldehyde, precursors thereof (for example, aldehyde acetals, orthoesters, etc.), and acrolein homopolymers and copolymers.

The polymerization method used in the present invention, a conventional polymerization method is used, may be solvent-free polymerization, may be solvent polymerization, but when controlling the temperature during the polymerization is exothermic solvent polymerization is It is advantageous. As the solvent, aprotic polar solvents such as diethyl ether, 1,2 dimethoxyethane and nitroalkane, aromatic hydrocarbons such as toluene, halogenated hydrocarbons such as dichloromethane, and aliphatic hydrocarbons such as heptane are used. The polymerization temperature is -100 to 120 ° C. The initiator is used at a concentration such that the monomer / initiator molar ratio is greater than 1. The amount of initiator can be varied according to known polymerization methods to control the molecular weight of the product.

(Effect) As can be understood from the above description, according to the present invention, which is characterized by using a solid acid as a catalyst in the polymerization of silyl vinyl ether using an aldehyde as an initiator,
After completion of the polymerization, the catalyst can be easily removed or recovered from the system by filtration, and the polymer can be efficiently obtained by a very simple operation. Further, even in the polymerization of trimethylsilyl vinyl ether, which has not been sufficiently polymerized or the yield was low in the prior art, the present invention makes it possible to obtain a polymer having a high yield and a high degree of polymerization. Further, in the present invention, since the chemical treatment for removing the catalyst is not required after the completion of the polymerization, the polymerization product is obtained as a silyl ether of polyvinyl alcohol as shown in the following formula (3).

(Here, Ar is an allyl group and R, R ′ and R ″ are the same as above.) Furthermore, for the polymer produced by the present invention, conventionally known methods can be used without limitation for modification such as polymer reaction and hydrolysis reaction. I can.

(Example) Hereinafter, although the Example of this invention is shown concretely, this invention is not limited to these Examples.

Example 1 In a reaction vessel equipped with an argon inlet tube, a stirrer and a thermometer, 3 ml of dichloromethane as a solvent, 0.021 g (0.2 mmol) of benzaldehyde as an initiator and aluminum-exchanged montmorillonite as a catalyst (average particle size 0.4 μm) 5
0 mg was added and cooled to 5 ° C. Next, 0.73 g (6.3 mmol) of trimethylsilyl vinyl ether as a monomer
Was added for 3 minutes and polymerized at 5 ° C. for 30 minutes.

After completion of the polymerization, the catalyst was removed by filtration, and the solvent and unreacted monomers were distilled off under reduced pressure to obtain 0.65 g (yield 86%) of a colorless transparent polymer. This polymer had a weight average molecular weight ▲ ▼ = 3262, a number average molecular weight ▲ ▼ = 1702, and a molecular weight distribution ▲ ▼ determined by gel permeation chromatography (hereinafter abbreviated as GPC).
/▲▼=1.98.

Comparative Example 1 In Example 1, instead of aluminum-exchanged montmorillonite as a catalyst, 56 mg (0.25 mmol) of zinc bromide was used.
Was used for polymerization at 5 ° C. for 5 hours. After completion of the polymerization, in order to remove the catalyst, sodium bicarbonate water was added for neutralization, the polymer was extracted with ether, the extract was washed twice with water, dried and concentrated to give 0.17 g of a colorless transparent polymer ( Yield 21
%) Was obtained. This polymer is from GPC, ▲ ▼ ＝ 990,
▲ ▼ ＝ 770, ▲ ▼ / ▲ ▼ = 1.29.

From the above results, when the solid acid specified in the present invention is used as the catalyst, not only the polymerization activity of trimethylsilyl vinyl ether is high, but also the post-process of the polymer is simple and the effect of the present invention is clear.

Example 2 In Example 1, iron-exchanged montmorillonite was used as the catalyst instead of aluminum-exchanged montmorillonite,
Polymerization was carried out at 30 ° C for 15 minutes.

0.62 g (yield 83%) of a colorless transparent polymer was obtained. ▲ ▼
= 1019, ▲ ▼ = 1497, ▲ ▼ / ▲ ▼ = 1.47.

Example 3 Instead of the aluminum-exchanged montmorillonite as the catalyst in Example 1, 50 mg of aluminum-exchanged fluorine tetrasilicon mica was used, 0.026 g (0.2 mmol) of P-cyanobenzaldehyde was used as an initiator, and polymerization was carried out at 30 ° C. for 10 minutes. It was

0.67 g (88% yield) of a colorless transparent polymer was obtained. ▲ ▼
= 1228, ▲ ▼ ＝ 1721, ▲ ▼ / ▲ ▼ = 1.40.

Example 4 In Example 1, 50 mg of aluminum-exchanged fluorine tetrasilicon mica was used instead of aluminum-exchanged montmorillonite as a catalyst, 0.034 g (0.2 mmol) of m-nitrobenzaldehyde dimethyl acetal was used as an initiator, and 3 ml of nitroethane was used as a catalyst. Polymerization was carried out at 0 ° C for 10 minutes.

0.59 g (77% yield) of a colorless transparent polymer was obtained. ▲ ▼
= 1067, ▲ ▼ = 1376, ▲ ▼ / ▲ ▼ = 1.29.

Example 5 Instead of aluminum-exchanged montmorillonite as a catalyst in Example 1, calcium-exchanged Y-type zeolite was used for polymerization at 30 ° C. for 50 hours.

0.46 g (yield 60%) of a colorless transparent polymer was obtained. ▲ ▼
= 768, ▲ ▼ = 1155, ▲ ▼ / ▲ ▼ = 1.50.

Example 6 In place of aluminum-exchanged montmorillonite as a catalyst in Example 1, silica-supported 12-molybdophosphoric acid (support amount: 10% by weight) was used, and polymerization was carried out at 30 ° C. for 2 hours.

0.44 g (yield 57%) of a colorless transparent polymer was obtained. ▲ ▼
= 1325, ▲ ▼ = 2496, ▲ ▼ / ▲ ▼ = 1.88.

Claims (1)

[Claims] 1. A method for producing a silyl vinyl ether polymer, which comprises using at least one solid acid selected from clay minerals and heteropolyacids as a catalyst when polymerizing a silyl vinyl ether using an aldehyde as an initiator.