JPH02200689A - Distillation of organic silicon compound - Google Patents

Abstract

PURPOSE:To prevent the deposition of solid material composed of impurity residue on a heating surface, etc., during distillation process and to enable continuous distillation of a high-boiling polymerizable organic silicon compound using a thin-film distillation apparatus by performing the distillation in the presence of a specific liquid having high boiling point. CONSTITUTION:An organic silicon compound of formula (R<1> is H or methyl; R<2> is hydrolyzable group; R<3> is 1-6C hydrocarbon group; X is O or S; m is 1-3; n is 8-20) is distilled with a thin-film distillation apparatus in the presence of a liquid (e.g. polydimethylsiloxane) inert to the above compound, having high boiling point and exhibiting vapor-pressure corresponding to <=1/10 of the vapor-pressure of the compound of formula at the distillation temperature. The amount of the high-boiling liquid is preferably 10-100 pts.wt. per 100 pts.wt. of the compound of formula. Preferably, the high-boiling liquid is mixed with the compound of formula in advance and the mixture is fed to the heating surface to effect the distillation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for distilling and purifying polymerizable organosilicon compounds having a high boiling point. Specifically, the present invention relates to a method for distilling and purifying the compound using a thin film evaporator in the presence of a liquid having a higher boiling point than the compound.

(Prior Art) The present inventors have proposed the following general formula [where R1 represents a hydrogen atom or a methyl group, R2 represents a hydrolyzable group, and R3 represents a hydrocarbon group having 1 to 6 carbon atoms] , X represents an oxygen atom or a sulfur atom, m
represents an integer from 1 to 3, and n represents an integer from 8 to 20] It has been found that an organosilicon compound represented by the following is preferable as a Solan coupling agent.

When these compounds are used as silane coupling agents, it is necessary to purify them after synthesis.
)] for which the purification method is known is the following compound H2C= C-Coo-(-CI12→ S i +O
CH3) Only 3. The compound is described by Sakanashi et al. [by Sakanashi and Nishiyama, Dental Materials and Instruments Yokofue Vol. 3, No. 2, pp. 2a4-294]
, 1984)] showed that it can be purified using silica gel column chromatography.

(Problem to be solved by the invention) However, although the purification method using column chromatography is suitable for purifying a small amount of sample, it is not a practical method for purifying a large amount of sample in a short time. do not have. Distillation is considered to be appropriate for this purpose, but compound (A)
I encountered great difficulties when trying to distill it. That is, since compound (A) has a high boiling point and polymerizability, in ordinary vacuum distillation, polymerization occurs in the distiller when heated to the distillation temperature.

Therefore, a thin film distillation apparatus, which is said to be able to efficiently distill high boiling point and unstable organic compounds, was used, but the following disadvantages occurred. That is, although the target compound (A) is distilled from the crude compound (A), as the distillation progresses, high molecular weight impurities produced as by-products during the synthesis become a residual aroma and leave the heated surface ( (evaporation surface) as a solid substance. As a result, it became clear that the formation of a thin film on the heated surface became difficult and the distillation line became clogged, making continuous operation for a long time difficult.

Therefore, an object of the present invention is to enable continuous operation for long periods of time during distillation purification of compound (A) using a thin-film distillation apparatus, without leaving the solid matter attached to the heating surface or distillation line during distillation. The purpose is to provide a method for getting used to it.

(Means for Solving the Problems) As a result of intensive studies in order to solve the above problems, the present inventors have found that by mixing a liquid with a higher boiling point than the compound (A) with the crude compound (A). If distillation is performed by heating the compound (A) on a heated surface, the solids that precipitate as the compound (A) evaporates will be discharged from the distillation apparatus in a state dissolved or suspended in the high-boiling point liquid due to the presence of the high-boiling point liquid. It has been found that the accumulation of the solids on the surface of the distillate is prevented, and long-term distillation operation becomes possible.

That is, the present invention is based on the following general formula [where R1 represents a hydrogen atom or a methyl group, R2 represents a hydrolyzable group, R3 represents a hydrocarbon group having 1 to 6 carbon atoms, and X represents an oxygen atom or Indicates a sulfur atom, m
represents an integer from 1 to 3, and n represents an integer from 8 to 20. An organosilicon compound expressed by ``co'' is inert to the compound and has a high boiling point in a thin film distillation apparatus. This is a method for distilling an organosilicon compound characterized by using a liquid whose vapor pressure at the distillation temperature is 1710 or less than the vapor pressure of the organosilicon compound.

The greatest feature of the present invention is that the crude compound (A) is fed into a thin film distillation apparatus together with a liquid having a higher boiling point than the crude compound (A),
The objective is to selectively distill compound (A). According to this method, the compound (mu) is evaporated on the heating surface of the device and then collected by a condenser to complete distillation purification. On the other hand, the high boiling point liquid does not evaporate and the crude compound (A
) are washed away from the heating surface in a dissolved state or in a suspended state as fine particles, and recovered as an evaporation residue.

Note that the low boiling point impurities contained in the crude compound (A) are
It is desirable to carry out distillation under reduced pressure before carrying out the distillation of the present invention.

Next, compound (A) will be explained below. The hydrolyzable group R2 in formula (A) specifically refers to an alkoxy group, a chlorine atom, an isocyanate group, an alkoxy group,
It is an iminoxy group. R3 means a hydrocarbon group or a halogenated hydrocarbon group in a narrow sense.

Specific examples of compound (A) include those shown below.

CI(3 1(, C= C-C'0O-(-CIl 2→S i
-(-OCII 3)CI(3 +1, C= C-COO-+CH, → Si-+-0
CH3)IL CH3CH2 O, C= C-Coo-(-C1l, → 5iCI2
z■, σ= c-coo-←CH2→ 5iC12sC
H3CH.

LC= C-C0O-(-C)l, → S i +OC
l(3) -φ CH3 II, C= C-C0O-(-CIl, → 5i
-(-NGO)3■ CIl, CF.

II, C=C-C0O-(-CIl 2→ 3
i −+OCII 3) 2Hv C= CCO3H(
II 2→ CH3) 3CI+ on Si.

H, C= f, -C0O-(-CH2→ Sl-+0O
CCII3)3?113 H2C= C-Coo→3o2→ Si-+0CH3)
3H3 11, C=C-Coo-1-CII2→5iCQ.

? 1. H2C2c-coo→1+2→ Si→■C1l*:L
+? 113 ILC= C-C00-(-(:I(2→ 5i-((
) C113) 3 Next, the high boiling point liquid used in the present invention will be explained. It is necessary to suppress as much as possible the high boiling point liquid from mixing into the fraction during distillation of the compound (A), and for this purpose, the vapor pressure of the high boiling point liquid at the distillation temperature is lower than that of the compound (A). It is desirable that the vapor pressure is 1710 or less. The boiling point of a high-boiling liquid with a vapor pressure of 171 O or less is usually 40°C or more higher than that of compound (A), which substantially causes a decrease in the purity of compound (A) due to contamination with the high-boiling liquid. Distillation purification is possible without

Another requirement for the high boiling liquid is that it must not alter compound (A) during distillation.

For this purpose, high-boiling liquids must have hydroxyl groups, carboxyl groups,
It must not have functional groups such as thiol groups, amino groups, epoxy groups, sulfonic acid groups, and phosphonic acid groups.

By the way, the high boiling point liquid referred to in the present invention is not limited to only a liquid that is liquid at room temperature. From that purpose,
It is sufficient that it is in a liquid state at the distillation temperature of compound (A).

Such high boiling point liquids include, for example, polydimethylsiloxane, polyoctylmethylsiloxane, polymethyldecyl-diphenylsiloxane copolymer, polydimethyl-
Diphenylsiloxane copolymer Polymer corn oil represented by polymethylphenylloxane, polydimedylphenylmethylsiloxane copolymer, etc. (the terminal nranol group is preferably protected with a trimethylsilyl group, etc.), hydroxyl groups at both ends of polyethylene glycol alkyl etherified or alkyl esterified, alkylated diphenyl ether or general formula (where Q is an integer of 1 to 4, n is an integer of 0 to 2, m is 1 or 0, and R is an alkyl group) ), petroleum fractions such as liquid paraffin, lubricating oil, and process oil are used.

These liquids may be used alone or in an appropriate mixture of two or more.

These high boiling point liquids are used in an amount of 10 to 1000 parts by weight per 100 parts by weight of crude compound (A). If the amount is less than 10 parts by weight, the effect of preventing the solids from forming into lumps and adhering to the heating surface of the distillation apparatus is insufficient, which is not preferable. On the other hand, if it exceeds 1000 parts by weight, the distillation rate will be slow and the energy efficiency of distillation will be extremely poor.

Note that it is preferable that the high boiling point liquid be mixed with the crude compound (A) in advance and fed to the heating surface.

A polymerization inhibitor is usually added in advance to the crude compound (A) in order to prevent deterioration of the (meth)acryloyl group during distillation. Examples of such weight inhibitors include 2.
6-di-butyl-p-cresol, hydroquinone monomethyl ether, 2.2°-methylene-bis-(4
-ethyl-6-t-butylphenol), tetrakis-
[Methylene-3 (3°, 5°-di-t-butyl-4°-
Hydroxyphenyl) propionate comethane, N, N
'-hexamethylenebis(3,5-di-t-butyl-4
-hydroxy-hydrocinnamamide), 2- (3,
5-di-butyl-4-hydroxybenzyl)2-n
-butylmalonate bis(1,2,2,6,6-bentamethyl-4-piperidyl), phenolics such as α-tocopherol, N,N'-di-β-naphthyl-p-phenylene-diaminephenothiazine, octyl In addition to amines such as diphenylamine chloride, iron chloride, copper chloride, etc. can also be used. These polymerization inhibitors may be used alone or in combination of two or more, and the amount added is usually in the range of 0.01 to 10 parts by weight per 100 parts by weight of the crude compound (A).

There are various types of thin film distillation apparatus used in the present invention. For example, there are falling film type, cascade type, wet wall type, short axis type, centrifugal type, rotor rotation type (Luwa thin film type), liquid column flow type, liquid film moving type, etc. In either case, the distillation operation is usually carried out by a method commonly used for these operations.

(Examples) Next, the present invention will be explained by examples, but the present invention is not limited to these examples.

Production Example 1 (Synthesis of 8-methacryloyloxyoctyltrimethoxine run) 300 g of 7-octynyl methacrylate and 1 g of hydroquinone monomethyl ether were placed in a reaction vessel equipped with a stirrer.
and 1% tetrahydrofuran solution of chloroplatinic acid hexahydrate 4
Add mQ and heat the mixture to 40°C = 11 -1 again. 250 g of trichlorosilane was gradually added dropwise to this under a nitrogen atmosphere while stirring, and during this time the temperature of the reaction mixture was kept at 4.
The temperature was adjusted so as not to exceed 5°C. After the dropwise addition was completed, the mixture was heated to 60°C, and the reaction was further carried out at this temperature for 6 hours to synthesize 8-methacryloyloxyoctyltrichlorosilane.

Next, add methanol 1000 II to a reaction vessel equipped with a stirrer.
IQ and 300 g of triethylamine were added and cooled to 0°C. The previously synthesized 8-methacryloyloxyoctyltrichlorosilane was slowly added dropwise to this mixture from the dropping funnel. After the dropwise addition was completed, the mixture was further stirred at room temperature for 12 hours. The solvent of this reaction mixture was distilled off under reduced pressure, a large amount of diethyl ether was added to the residue, insoluble matter was filtered off, and the ether was distilled off under reduced pressure to obtain 430 g of crude 8-methacryloyloxyoctyltrimethoxysilane. .

Production Example 2 (Synthesis of 11-methacryloyloxyundecyltrimethoxysilane) Synthesis was carried out in the same manner as in Production Example 1 using 360 g of 11-undecenyl methacrylate, resulting in the crude production of 11-methacryloyloxyundecyltrimethoxysilane. 450g of material was obtained.

Production Example 3 (Synthesis of 16-methacryloyloxyhexadecyltrimethoxysilane) Synthesis was carried out in the same manner as in Production Example 2 using 415 g of 16-hexadecenyl methacrylate. 480 g of crude product was obtained.

Example 1 Crude 8-methacryloyloxyoctyltrimethoxysilane loog synthesized in Production Example 1, polydimethyl-diphenylsiloxane copolymer [Shin M Silicone K F
-540, boiling point = 200°C or higher (vapor pressure 4X 10-3 mmHg or lower at 200°C) and tetrakis-[methylene-3 (3', 5°-
di-t-butyl-4°-hydroxyphenyl) propionate comethane (Ciba Geigy Irganox 1040
■) Ig was mixed and dissolved. This mixed solution was distilled into a rotary thin film distillation device (Molecular distillation device M, S-S by Shibata Scientific Instruments Co., Ltd.).
300 type) at a pressure of 0. O3mmHg.

Thin film distillation was carried out at a distillation temperature of 90° C. for about 2 hours according to a conventional method. As a result, 8-methacryloyloxyoctyltrimethoxysilane containing Hg was distilled. Furthermore, the polymer did not precipitate in lumps on the evaporation surface during the distillation, and the thin film distillation was carried out satisfactorily from beginning to end. 114 g of non-volatile components were collected as a liquid residue and no solids were deposited on the residue outlet line.

Analysis by gas chromatography showed that the purity of distilled 8-methacryloyloxyoctyltrimethoxysilane was 91.5%, and 'H-NMR analysis showed that no KF-54 component was mixed. Furthermore, gas chromatography and ')l-NMR analysis of the residue revealed that 8-
Almost no methacryloyloxyoctyltrimethoxysilane remained.

Comparative Example 1 In Example 1, crude 11 was prepared without using KF-54.
Methacryloyloxyoctyltrimethoxysilane 10
When a mixed solution of 0g and IrganoxlO1OIg was subjected to thin film distillation in the same manner as in Example 1, solid matter gradually precipitated on the evaporation surface, and the solid matter formed into lumps at the bottom of the distillation column. It became difficult to form a thin film at the stage where about 40 g of the solution was stagnated and fed, and it was not possible to distill all of the charged material.

Examples 2 and 3 Using 100 g each of the crude products of 11-methacryloyloxyundecyltrimethoxysilane and 16-methacryloyloxyhexadecyltrimethoxysilane synthesized in Production Examples 2 and 3, the pressure, temperature, and time shown in Table 1 were carried out. The results of thin film distillation performed in the same manner as in Example 1 are also shown in Table 1.

In either case, as in Example 1, the organosilicon compound and K
Separation from F54 was good. Furthermore, no solid matter was deposited on the evaporation surface or line.

Example 4 Commercially available vacuum pump oil (Neovac M manufactured by Matsuzai Oil Research Institute)
R-250■) 200g was distilled using the thin film distillation apparatus used in Example 1 at a pressure of 0.0[17mn+t1gS and a temperature of 145°C and fractionated into volatile components and non-volatile components. 150 g of liquid was obtained as a component. 100 g of this liquid, 10 crude products of 11-methacryloyloxyundecyltrimethoxysilane
When 1 g of lrganox 1010 and 1 g of lrganox 1010 were mixed and dissolved and the mixture was subjected to thin film distillation under the same conditions as in Example 2, 76 g of an organosilicon compound was distilled (purity 89.6%). Also, 120 g of liquid was collected as a non-volatile residue.

(Effect of the invention) By the distillation method of the present invention, it has become possible to efficiently distill and purify a high boiling point polymerizable organosilicon compound expressed by formula (A) in large quantities without polymerizing during distillation. .

Claims (1)

[Claims] The following general formula ▲ includes mathematical formulas, chemical formulas, tables, etc. ▼ [However, R^1 represents a hydrogen atom or a methyl group, and R^2
represents a hydrolyzable group, and R^3 has 1 to 6 carbon atoms.
represents a hydrocarbon group, X represents an oxygen atom or a sulfur atom, m represents an integer from 1 to 3, and n represents an integer from 8 to 20. A method of distilling using a thin film distillation apparatus in the presence of an inert liquid with a high boiling point, wherein the vapor pressure of the liquid at the distillation temperature is 1/10 or less of the vapor pressure of the organosilicon compound. A method for distilling an organosilicon compound, characterized by using a certain liquid.