JPS63253090A - Silyl (meth)acrylate having trimethylsiloxy group - Google Patents

Abstract

NEW MATERIAL:The compound of formula (R<1> is H or methyl; R<2> is methyl or trimethylsiloxy; at least two of R<2> are trimethylsiloxy). EXAMPLE:Tris(trimethylsiloxy)silyl methacrylate. USE:A carrier for slowly releasing formulation and agricultural chemicals. It has easily controllable rate of hydrolysis and is easily producible. PREPARATION:The objective compound can be produced e.g. by reacting tris(trimethylsiloxy)silane or bis(trimethylsiloxy)monomethylsilane with (meth)acrylic acid in the presence of a dehydrogenation catalyst.

Description

Detailed Description of the Invention [Field of the Invention] The present invention provides novel trimethylsiloxy group-containing (meth)
Concerning acrylates.

[Technical background of the invention and its problems] Various silane compounds are known in which a carbon functional group is bonded to a silicon atom via a silicon functional bond.

Among them, trimethylsilyl (meth)acrylate is known as a silane compound in which a methacryloxy group is bonded to a silicon atom (D, N).

Andreev, at al; Zhurnal
0bsbcbei Kbfmii, Volume 30, No. 278
2 (1980)).

However, this compound has strong hydrolyzability and easily reacts with moisture in the air, decomposing it into hexamethyldisiloxane and (meth)acrylic acid, making it impractical as a reaction reagent. Ta.

Pentamethyldisiloxanyl methacrylate having siloxane steel is also known, but its hydrolyzability is almost the same as that of the above-mentioned trimethylsilyl (meth)acrylate.

Furthermore, triethylsilyl (meth)acrylate, tripropylsilyl methacrylate, and tributylsilyl methacrylate are known, and each of these has a higher hydrolyzability between the (meth)acryloxy group and the silicon atom than trimethylsilyl (meth)acrylate. It is also known that the smaller the number of carbon atoms in the bonded alkyl group, the weaker the hydrolyzability (D, N, Andreev, et al.;
Zhurnal Obshehei Khimii, Volume 38, Page 2123 (198B)).

However, trialkylsilyl (meth)acrylates, in which as many as three alkyl groups with two or more carbon atoms are bonded to silicon atoms, can be synthesized using methyl chloride and metallic silicon as raw materials, which is the most efficient synthesis method in organosilicon chemistry. It is industrially disadvantageous that the product of the direct synthesis method cannot be used, and even when the Grignard method is applied, the synthesis is complicated, such as requiring large amounts of Grignard reagents and ether solvents. There is a side. Furthermore, polymers containing phenyl groups or tolyl groups tend to have a high glass reversing point.

[Objective of the invention] The present invention solves the above problems, and has low hydrolyzability.
An object of the present invention is to provide a trimethylsiloxy group-containing silyl (meth)acrylate that is easy to control and easy to manufacture.

[Configuration of the Invention] The present invention provides general formula (I): CH2=CRICOOS i (R2)s (I
) (in the formula, R1 represents a hydrogen atom or a methyl group; R2 represents a methyl group or a trimethylsiloxy group;
2, at least two of which are trimethylsiloxy groups).

In the silane compound represented by formula (I), groups) 11 and R2
is defined as above, but it is preferable that all of the groups R2 are trimethylsiloxy groups because synthesis is easy and hydrolysis rate can be easily controlled.

Examples of the trimethylsiloxy group-containing silyl (meth)acrylate represented by formula (I) include bis(trimethylsiloxy)methylsilyl acrylate, tris(trimethylsiloxy)silyl acrylate, and the corresponding methacrylate. Among these, tris(trimethylsiloxy)silyl(meth)acrylate is preferred because it has a high degree of branching in the molecule and has a slow hydrolysis rate.

The trimethylsiloxy group-containing silyl (meth)acrylate represented by formula (I) is, for example, tris(trimethylsiloxy)silane or bis(trimethylsiloxy)
Monomethylsilane can be obtained by reacting with acrylic or methacrylic acid in the presence of a dehydrogenation catalyst. Hereinafter, a manufacturing example will be given and explained.

First, acrylic acid or methacrylic acid is poured into an organic solvent such as an aprotic solvent, and then stirred to make it homogeneous.Next, a dehydrogenation catalyst such as Pd-C is added, heated, and stirred. .

Thereafter, a trimethylsiloxy group-containing hydrosilane is added by a dropwise method or the like, and the mixture is further stirred to cause a reaction. Note that the trimethylsiloxy group-containing hydrosilane used here can be obtained, for example, by cohydrolyzing trichlorosilane or methyldichlorosilane and trimethylchlorosilane in an ether solvent.

After the reaction is completed, the catalyst is removed by an appropriate method such as filtration, followed by purification and drying to obtain trimethylsiloxy group-containing silyl (meth)acrylate.

[Effects of the Invention] The trimethylsiloxy group-containing silyl (meth)acrylate of the present invention has a methyl group bonded to the silicon atom to which the (meth)acryloxy group is bonded via a siloxane bond. The hydrolysis rate is slower than trimethyl (meth)acrylate, which has three methyl groups bonded to it, and it can be easily controlled, so it can be used as a slow-acting reaction reagent by utilizing these properties.

In addition, the trimethylsiloxy group-containing silyl (meth)acrylate of the present invention is easy to synthesize because it does not contain an alkyl group having two or more carbon atoms in its molecule,
Industrially advantageous.

Further, the trimethylsiloxy group-containing silyl (meth)acrylate polymer of the present invention is useful as a carrier for sustained release preparations and agricultural chemicals because of its property of being gradually hydrolyzed and its safety.

[Example] Hereinafter, the present invention will be explained with reference to Examples. In addition, in Examples and Synthesis Examples, all "1 part" represents "part by weight".

Synthesis Example 1 In a reaction vessel equipped with a stirrer, condenser and thermometer, 4
00 parts of ether and 400 parts of water were charged and stirred. Then, 136 parts of trichlorosilane and 3
30 parts of trimethylchlorosilane was added dropwise over 60 minutes to cause a reaction.

After the reaction was completed, the organic phase was taken out using the outside of the separating furnace, and the solvent and unreacted substances were distilled off under normal pressure. After that, under reduced pressure (3O
Torr) to obtain 101 parts of a fraction with a boiling point of 85°C. This fraction was confirmed to be tris(trimethylsiloxy)silane from the IR spectrum and NMR spectrum. The yield was 34% of theory.

Example 1 Into a reaction vessel equipped with a stirrer, condenser, thermometer and heating jacket, 200 parts of dimethylformamide,
After charging 86.1 parts of methacrylic acid and 4 parts of Pd-C, the temperature was raised to 80°C with stirring, and then 297 parts of tris(trimethylsiloxy) obtained in Synthesis Example 1 was added while keeping the temperature constant. ) Silane was added dropwise and reacted.
After the reaction was completed, the catalyst was separated from the furnace, and then the solvent and unreacted substances were distilled off under normal pressure. Thereafter, it was rectified under reduced pressure (2 Tarts) to obtain 304 parts of a fraction with a boiling point of 160°C. This fraction was obtained from gas mass spectra, elemental analysis, IR spectra, and NMR spectra.

It was confirmed that it was tris(trimethylsiloxy)silyl methacrylate. The yield was 81% of theory.

The analytical values and characteristic absorption of this fraction are shown in Table 1, and the IR spectrum is shown in the figure.

Table 1 Synthesis Example 2 Using 115 parts of methyldichlorosilane instead of trichlorosilane, the amount of trimethylchlorosilane used was 22 parts.
It was produced in the same manner as in Synthesis Example 1 except that the amount was 0 part, and finally rectification was performed under reduced pressure (30 Torr) to obtain a fraction with a boiling point of 65°C. This fraction was confirmed to be bis(trimethylsiloxy)methylsilane from the IR spectrum and NMR spectrum. The yield was 36% of theory.

Example 2 Instead of tris(trimethylsiloxy)silane, 23
It was produced in the same manner as in Example 1 except that the bis(trimethylsiloxy)monomethylsilane obtained in Part 3 of Synthesis Example 2 was used, and finally rectification was performed under reduced pressure (2 orr) to obtain a product with a boiling point of 138 235 parts of a fraction at °C were obtained. This fraction was confirmed to be bis(trimethylsiloxy)methylsilyl methacrylate from the gas mass spectrum, elemental analysis, IR spectrum, and NMR spectrum. The yield was 77% of theory. The analytical values are shown in Table 2.

Table 2 Example 3 Produced in the same manner as in Example 1 except that 72.1 parts of acrylic acid was used instead of methacrylic acid, and finally rectified under reduced pressure (2 Torr) to achieve a boiling point of 279 parts of a fraction at 133°C were obtained. This fraction was confirmed to be tris(trimethylsiloxy)silyl acrylate from the gas mass spectrum, elemental analysis, IR spectrum, and NMR spectrum. The yield was 76% of theory. The analytical values are shown in Table 3.

Table 3 Test Example First, - 20% in a total of 6 beakers of 1001 Ikl.
Then, Examples 1 to 3 shown in Table 4 were added to the ethanol aqueous solution in an amount of 100 d each.
The (meth)acrylate compound obtained in 2.5X and three types of methacrylate compounds as comparative test examples were each
The reaction was allowed to proceed while dropping 10-3 moles at a time, and the electrical conductivity of the reaction system during expansion was measured at intervals of several seconds to several minutes, and the amount of acrylic acid or methacrylic acid produced was shown in Table 4 Half-life (T3) of meth)acrylate compounds
4) Then, from this half-life, the following formula: Ko
The reaction rate constant was determined based on b s=l n2/TH, and the hydrolyzability was evaluated. The results are shown in Table 4.

Table 4 As is clear from Table 4, the trimethylsiloxy group-containing silyl (meth)acrylates obtained in Examples 1 to 3 exhibit very weak hydrolyzability compared to trimethylsilyl methacrylate, and tributylsilyl methacrylate and tributylstannyl methacrylate.

[Brief explanation of drawings]

The figure represents the IR spectrum of the compound obtained in Example 1.

Claims (2)

[Claims] (1) General formula (I): CH_2=CR^1COOSi(R^2)_3(I)
(In the formula, R^1 represents a hydrogen atom or a methyl group; R^2
represents a methyl group or a trimethylsiloxy group, where at least two of R^2 are trimethylsiloxy groups) A trimethylsiloxy group-containing silyl (meth)acrylate. (2) In the compound represented by the general formula (I), the group R
The trimethylsiloxy group-containing silyl (meth) according to claim 1, wherein all ^2 are trimethylsiloxy groups.
Acrylate.