JPS60163887A - Cyclosiloxane derivative - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (In the formula, X is a perfluoroalkyl group having 1 to 12 carbon atoms, a perfluoroalkoxy group, a pentafluorophenyl group, or a pentafluorophenoxy group.

Substituted phenyldimethylsilyl group, dimethyl (fluorine-containing substituted alkyl)silyl group, polyfluoroalkylmethyloxycarbonyl group'), l is 2 to 4, m and n are positive integers, m + n = 5 to 6.

n/m is 0.2-50. ) Regarding the cyclosiloxane derivative represented by. The cyclosiloxane derivative represented by the general formula (I) is useful, for example, as an intermediate for producing durable silicone rubber or oxygen-enriched membranes.

Particularly in recent years, methods using polymer membranes have been attracting attention as a method for separating oxygen gas from air.

The desired properties of the polymer membrane used for this purpose are high selectivity between oxygen gas and 9-element gas, and a large amount of permeation of oxygen gas. In particular, the latter requires miniaturization of the separation device,
This is extremely important in increasing the amount of gas that can be processed.

In order to obtain a large amount of oxygen gas permeation, it is necessary to select a membrane material with a large oxygen gas permeability coefficient Po2 and to make the membrane thickness as thin as possible.

A polydimethylsiloxane film is known as a film having a large amount of PO2. However, polydimethylsiloxane has low mechanical strength when formed into a film, so it
If the thickness is less than m, the film cannot be made to withstand actual use. For this reason, it is difficult to obtain a thin film having a sufficient amount of gas permeation. For the purpose of improving the mechanical strength of this membrane, copolymers of polydimethylsiloxane and polycarbonate or polyα-methylstyrene, etc., have been developed, but the permeability coefficient P02 of oxygen gas decreases and separation The results were not necessarily satisfactory, as the coefficient α was insufficient.

As a result of intensive study on these points, the inventors found that
Contains a specific amount of silphenylene group in the main chain, perfluoroalkyl group or perfluoroalkoxy group in the side chain,
A film made of a siloxane copolymer having pentafluorophenyl groups etc. shows high Po2 and α and also has excellent film formability, and as an intermediate for its production, a cyclo The present invention was completed based on the discovery that siloxane derivatives are useful.

That is, as a repeating unit of a selectively permeable membrane that can be synthesized from the cyclosiloxane derivative represented by the general formula (I) of the present invention, the following general formula (wherein, X is a perfluoroalkyl group or perfluoroalkoxy group having 1 to 12 carbon atoms) is used. , pentafluorophenyl group, pentafluorophenoki 7 group.

Substituted phenyldimethylsilyl group, dimethyl (fluorine-containing substituted alkyl)silyl group, polyfluoroalkylmethyloxycarbonyl group, l is 2-4. n/m is 0.
2-5.0. q is 100 or more. ) and p/q
A siloxane copolymer in which ≦1 can be exemplified.

Examples of the siloxane copolymer represented by the general formula (II) that can be derived from the compound of the present invention include FI'IF and the like.

As the cyclosiloxane derivative of the present invention, etc. can be exemplified.

Hereinafter, the method for synthesizing the compound of the present invention will be explained in detail by route.

The compound of the present invention can be synthesized, for example, by the following four routes.

(V) (Vl) Route 1 This route uses dimethyldichlorosilane and the general formula (I
The cyclosiloxane compound represented by the general formula (T) is produced by cohydrolyzing the dichlorosilane derivative represented by II).

The raw material dimethyldichlorosilane is easily available at low cost and in large quantities. Some of the dichlorosilane derivatives are commercially available, and can also be easily synthesized by a hydrosilylation reaction between the corresponding olefin and methyldichlorosilane. For example, etc.

In the cohydrolysis reaction, the presence of water is essential, and the dichlorosilane is preferably dissolved in a solvent. Water is required in an amount of at least 2 equivalents or more based on the raw material compound, and is generally used in a large excess amount. As the solvent, diethyl ether, n-hexane, cyclohexane, benzene, toluene, etc. can be used. By using a water-immiscible solvent and reacting at the interface with water, the yield of the cyclosiloxane compound obtained can be increased. can be increased. Further, it is desirable that the concentration of dichlorosilane is 5.0 mol/l or less. This reaction is usually carried out at room temperature,
Since the reaction is exothermic, it may be cooled with ice water or the like.

Route 2 This route produces a cyclosiloxane represented by the general formula (T) by reacting a hydrosilane type cyclosiloxane represented by the general formula (IV) with an olefin represented by the following general formula % (). This is a reaction route for synthesizing derivatives.

The hydrosilane-type cyclosiloxane represented by the general formula (IV) as a raw material can be synthesized by the same method as in Route 1 by cohydrolyzing dimethyldichlorosilane and methyldichlorosilane. (See Reference Example 1) Examples of the other raw material, the olefin represented by the general formula (■), include perfluoroalkylethylene,
Examples include pentafluorophenyl ethylene, perfluoroalkyl acrylate, perfluoroalkyl methacrylate, perfluoroalkyl allyl ether, pentafluorophenyl allyl ether, and the like.

The use of a catalyst is essential for the reaction, and chloroplatinic acid (H□Pt C16.6H,O) is most commonly used as a catalyst, but metal complexes containing palladium and rhodium are also used. It is possible. For example, (Ph
5P) Pd, (Ph5P)2PdC11゜(PhC
N)2Pd(J,, (Ph,P)3RhCI, (P
h, PH), Rh(J.

(PhsP)2 (Co) RhCl, C(C2H
11)3 PTII! (Co)RhCA! etc. can be used as a catalyst.

The reaction is preferably carried out in a solvent, and examples of the solvent include hexane, benzene, toluene, acetone, trichloroethylene, carbon tetrachloride, THF, and the like.

The reaction temperature is preferably in the range of 60°C to 160°C, and preferably in an atmosphere of an inert gas such as argon or nitrogen.

Route 3 This route involves reacting a vinyl cyclosiloxane represented by the general formula (V) with a hydrosilane represented by the following general formula (wherein R is the same as above) in the presence of a catalyst. This is a reaction route for synthesizing a cyclosiloxane derivative represented by the following general formula (I).

The raw material vinyl cyclosiloxane can be synthesized from dimethyldichlorosilane and methylvinyldichlorosilane in the same manner as in Route 1 above. (See Reference Example 2) Examples of the hydrosilane represented by the general formula (■), which is the other raw material, include (wherein a and b each represent an integer of 1 to 5). .

The reaction conditions such as the type of catalyst used in this reaction and the reaction temperature of the solvent 1 are exactly the same as in the case of Route 2 above.

Route 4 This route is to synthesize a cyclosiloxane derivative represented by the following general formula (U) by reducing the iodine-substituted cyclosiloxane represented by the above general formula (Vl).

(In the formula, Rf represents a perfluoroalkyl group.) The iodine-substituted cyclosiloxane compound represented by the general formula (Vl) as a raw material is a vinyl-type cyclosiloxane used as a raw material in Route 6, and a perfluoroalkyl iosite. R
u3 (Co)12! Fe2 (CO)g +Fe
It can be obtained by addition in a solvent such as chloroform, methylene chloride, carbon tetrachloride, etc. in the presence of a catalyst such as 3 (Co)12. Various types of perfluoroalkyl iosites are commercially available and are easily available.

As a reducing agent, LiA/H4, BH3, NaBH4+
Nap(CT'J)H3+ LiBH41(CHs)
4 NBIFT4 + NaAlH4 + NaAIH2 (
OCH2CH20CH3)21 [, (n-C,H,)
3Sn) 20 etc. can be used, and a reducing agent is added in an equimolar amount or a slight excess amount of the raw material (VI) at room temperature in a solvent such as TI(F, benzene, toluene, diethyl ether, diglyme, xylene, etc.) The reaction proceeds easily.The cyclosiloxane represented by the general formula (■'U) thus obtained is more resistant to heat, acids, and alkalis than the cyclosiloxane represented by the general formula (Vl). On the other hand, it not only has improved stability and is easy to purify, but also can be a useful raw material in the polymerization reaction described later.

The perfluoroalkyl group in the general formula (I") is, for example, (-CF2±CF3.÷CF2fCFs
.

+ CF2+rCF,l, + CF-"CFa,+
CF-“CF3 +÷cgyaCF,.

-CI'CF, CF8. -CF2-C, F-CF part,
-C1q-OF'-CFCF.

C people CF3CF9C horses CF3 -CF2-CF-C1''-CFS, -C (C6 included, etc.) can be mentioned.

Below, a method for deriving a siloxane copolymer from the compound of the present invention will be exemplified.

Using the compound of the present invention, a polysiloxane represented by the following general formula (IX) is formed through the two steps shown in the following formula to form a film having excellent film-forming properties and excellent selective permselectivity for oxygen gas. A copolymer represented by the above-mentioned general formula (Tsukuda) can be synthesized as a raw material.

First step This step is to produce a polysiloxane derivative represented by the general formula (TX) by subjecting the cyclosiloxane derivative represented by the general formula (I) to ring-opening polymerization in the presence of a catalyst. .

The use of a catalyst is essential for the reaction, and the catalyst is approximately 1/10 to 1/10 of the cyclosiloxane represented by the general formula (D).
A viscous polysiloxane can be easily synthesized by adding 115 parts by weight of a catalyst and heating at 60 DEG C. to 150 DEG C. for usually 10 minutes to 2 hours under an inert gas atmosphere such as argon or nitrogen. As a catalyst, any catalyst generally used for ring-opening polymerization of cyclosiloxane can be used; for example, as an acid catalyst, concentrated sulfuric acid can be used.

Activated clay 2 strongly acidic ion exchange resins, etc., and alkaline catalysts such as NaOH, KOH! (Ch13) 4N
OH etc. can be used.

Second step This step involves dehydration condensation polymerization of the polysiloxane derivative represented by the general formula (TX) with p-bis(dimethylhydroxysilyl)benzene in the presence of a catalyst. This method produces a polysilphenylene siloxane/polysiloxane copolymer. The raw material p-bis(dimethylhydroxysilyl)benzene is a commercially available compound.

By changing the mixing ratio of polysiloxane and p-bis(dimethylhydroxysilyl)benzene during polymerization, it is possible to control the composition ratio (the value of p/q in the general formula (II) above) to any desired value. However, in this case, it is preferable that the degree of polymerization p of the silphenylene unit is at least 20 or more from the viewpoint of film formability.

The presence of a catalyst is essential for the reaction, and examples of the catalyst include acid-base catalysts such as tetramethylguanidine di-2-ethylhexoate and n-hexylamine 2-ethylhexoate (Hyde, J.F., Fr, P
At, 1,263,448) can be used, and a catalyst amount of 1/100 part by weight or less of the raw material is sufficient.

The reaction is preferably carried out in a solvent while azeotropically removing water produced as the reaction progresses. As the solvent, any organic solvent can be used as long as it is not miscible with water and has an azeotrope with water, such as benzene, toluene, and xylenna. A copolymer with a high degree of polymerization can be obtained by controlling the reaction temperature to the boiling point and reflux temperature of the solvent and carrying out azeotropic dehydration condensation for usually about 5 to 12 hours.

Most of the copolymers obtained in this step are soluble in organic solvents such as benzene, toluene, THF, diethyl ether, chloroform, methylene chloride, and carbon tetrachloride, and insoluble in alcohols or water. In addition, by dissolving this copolymer in the above-mentioned soluble organic solvent and casting the solution onto, for example, a glass plate or a Teflon plate and gradually evaporating the solvent, a thin film with a thickness of several μm to several tens of μm can be produced. It was found that the obtained membrane had excellent permeability to oxygen gas. (See Reference Example 8) The present invention will be explained in more detail below using Examples and Reference Examples. However, it goes without saying that the present invention is not limited to these.

Example 1 Dimethyldichlorosilane 30.8, P (0,239
Dissolve 50.49 (0,239 mol) of 3,3.3-)lifluoropropylmethyldichlorosilane in 200 ml of ether, and add this solution to 200 ml of ether.
1. The mixture was added dropwise to a mixed solution of 400 ml of pure water under an argon gas stream at room temperature for 6 hours for cohydrolysis.

After completion of the dropwise addition, take out only the ether layer from the reaction solution and neutralize it with an aqueous sodium bicarbonate solution and pure water.

After washing, it was dried using magnesium sulfate.

After removing the solvent and distilling under reduced pressure, 15ol)Tg
It was obtained with a boiling point range of 70°C to 120°C. As a result of NMR measurement, the average composition of this cyclosiloxane is ml n = 60 / 40 (mole%)
Met.

Example 2 Dimethyldichlorosilane 42.2.9 # (0,327 mol) and heptafluoroisopropoxypropylmethyldichlorosilane 27.6 # (0,081 mol) were dissolved in 200 ml of ether, and this solution was dissolved. ether 2
The mixture was added dropwise to a mixed solution of 400 ml of pure water under an argon gas stream at room temperature for about 5 hours for cohydrolysis. After dropping, take out only the oil layer from the reaction solution, neutralize and wash with aqueous sodium bicarbonate solution and pure water,
It was dried using magnesium sulfate and distilled under reduced pressure. As a result, the average composition of this cyclosiloxane was m/n=72/28 (mole%) as a result of NMR measurement in the boiling point range of 102°C to 185°C at 13 mmHg.

Reference example 1 (raw material preparation example) Dimethyldichlorosilane 159.619 (1.24 mol), methyldichlorosilane 55.311 (0.4
(8 mol) was dissolved in 200 ml of ether, and this solution was added dropwise to a mixed solution of 200 i+l of ether and 400 ml of pure water at room temperature under an argon gas stream for about 5 hours for cohydrolysis. After completion of the dropwise addition, only the ether layer was taken out from the reaction solution, neutralized and washed with an aqueous sodium bicarbonate solution and pure water, dried over magnesium sulfate, and distilled under reduced pressure. As a result, the average composition of this cyclosiloxane is m
/n=73/27 (mole%). In addition, when GC-MS analysis was performed, this cyclosiloxane mixture was found to have the following 9 cyclosiloxane mixtures with different m and n.
It consisted of ingredients.

rn = 2 r n = 1 (5,9wt%) + f
n-3+ l'l-o.

(4, Owt%), m=n=2 (14,9wt%)
.

m = 3. n = 1 (3B, 9 wt%),
m=4. n=0(25.8wt%)+m=2. n=
5 (2.6wt%).

m=5. n=2 (4.4wt%), m=4. n=
1 (2,9wt%L m=5.n=o (0,6wt%
).

Example 3 12.5.9 cyclosiloxane obtained in Reference Example 1 and 1 t 2.9 of pentafluorostyrene were mixed in 40 toluene.
ml of chloroplatinic acid ethanol solution (0,193
mole/l) 201 tl was added thereto, heated to 80°C under an argon gas stream, and stirred for 19 hours. When this solution was measured by IR measurement, it was found that 5 liters of the raw material cyclosiloxane
The absorption peak (2175crIL) based on the -H bond had completely disappeared. After washing the reaction solution with pure water and drying, the solvent was removed and distilled under reduced pressure. As a result, 1-5 mH
The average composition of C with a structure with a boiling point range of 115 °C to 111 °C in g is m / n = 73 / 27 (mo
le%). Moreover, as a result of GC-MS analysis, this cyclosiloxane mixture mainly had m=3. n=
1 (15.7wt%), m=n=2 (80.8w
t%), m=4°n=1 (3.5wt%).

Example 4 7.0 g of cyclosiloxane obtained in Reference Example 1 and 8.1 g of topentafluorophenyl-3-butenyl ether were dissolved in 30 ml of toluene, and a solution of chloroplatinic acid in ethanol (0,193 mole/J) 20 All Add
The mixture was heated to 80° C. under an argon gas stream and stirred for 18 hours. When this solution was measured by IR measurement, an absorption peak (217
5m) had completely disappeared.

After washing the reaction solution with pure water and drying, g of the solvent was completely removed. As a result of NMR measurement, the average composition is m / n = 68
/ 32 (mole%), and according to GCMS analysis, this cyclosiloxane mixture is mainly m-3゜n =
1 (90.5wt%) + m = n = 2 (
It consisted of two components: 9.7 wt%).

Example 5 Cyclosiloxane obtained in Reference Example 1 5.0 g ton
-Perfluorobutylethylene 4011 to toluene 20
Dissolved in chloroplatinic acid ethanol solution (0,19
3 moIe/l) 20 μm was added, heated to 80° C. under an argon gas stream, and stirred for 6 hours. When this solution was measured by IR measurement, it was found that 5t of the raw material cyclosiloxane
The absorption peak (2175 cm) based on the -H bond had almost disappeared. After washing the reaction solution with pure water and drying,
When the solvent was removed and vacuum distillation was performed, 1. Ox*
A cyclosiloxane mixture with a structure consisting of 38°C in Hg! 1.9 Fl was obtained. As a result of NMR measurement, the average composition was m/n=76/24 (mole%).

Example 6 042 g of cyclosiloxane obtained in Reference Example 1
Dissolve 57 g of H,I H,11H-icosafluoroundecyl acrylate in Bml of toluene, add 2 μj of chloroplatinic acid ethanol solution (0,193 mole/l), and heat to 80°C under an argon gas stream. It was stirred for 6 hours. When this solution was subjected to IR measurement, the absorption peak (2175crrL) based on the Si-H bond of the raw material cyclosiloxane had completely disappeared. After washing the reaction solution with pure water and drying, the solvent was completely removed to obtain 3.5 g of a cyclosiloxane mixture having the following structure. According to NMR, its average composition is m/n −77
/23 (mole%).

Reference example 2 (raw material preparation example) Dimethyldichlorosilane 49.7 f9 (0,385
mol) and methylvinyldichlorosilane 27.2 #(
0,191 mol) in 150 m of ether, and this solution was dissolved in 100 m7 of ether! The mixture was added dropwise to a mixed solution of 150 WL of pure water at room temperature under an argon gas stream over a period of about 7 hours for cohydrolysis. After completion of the dropwise addition, only the ether layer was taken out from the reaction solution, neutralized and washed with an aqueous sodium bicarbonate solution and pure water, dried over magnesium sulfate, and distilled under reduced pressure.

As a result, the average composition of this cyclosiloxane is m/n=
It was 76/24 (mole%). Also, GC-
MS analysis revealed that this cyclosiloxane mixture consisted of the following five components with different m and n values.

m=3. n=o (1.6 wt%), m=4. n=0
(35,9wt%), m=3+n=1 (4B,3
wt%)+m=n=2 (12,6wt%)1m-1,
n=3 (1.6 wt%).

Example 7 31 g of cyclosiloxane obtained in Reference Example 2 and 5.9 g of pentafluorophenyldimethylsilane were dissolved in 10 m/ml of toluene, and a solution of chloroplatinic acid ethanol (0,
193 mole/J) 7 μl was added, heated to 80° C. under an argon gas stream, and stirred for 24 hours. NMR measurement of this solution revealed a proton peak (5.58 ppm) based on the vinyl group of the raw material cyclosiloxane.
) had almost disappeared.

After washing the reaction solution with pure water and drying, completely remove the solvent at -72
/28 (mole%), and according to GC-MS analysis, this cyclosiloxane mixture is mainly m-3! n
-1 (66,3 wt%), m=n=2 (17,3 wt%
), m=4. It consisted of three components with n=1 (5.7 wt%).

Example 8 5.0 g of cyclosiloxane obtained in Reference Example 2 and 15.0 I9 of perfluorooctyl iosite were dissolved in 25 ml of chloroform, and RL+, (Co), □0.02
#1 0.5-liter of ethanolamine was added and the mixture was refluxed for 2 hours under an argon stream. After washing the reaction solution with water and drying, cyclosiloxane 17.89 having a soluble structure was obtained. N
As a result of MR measurement, the average composition is m / n = 59
/41 (mole%).

Next, add 178g of the above cyclosiloxane to 50ml of THF.
2.1 g of lithium aluminum hydride was gradually added to the solution under vigorous stirring under an argon stream, and after the addition was completed, the mixture was further stirred at room temperature for 1 hour. After terminating the reaction by adding 2 ml of ethanol, the reaction solution was sequentially washed with an aqueous hydrochloric acid solution, a hydrogen carbonate solution, an IJ ram solution, and pure water, dried, and then the solvent was removed and distilled under reduced pressure. The result is 0
．． 5. A cyclosiloxane mixture having the structure: 5.
7g was obtained. According to NMR measurement, its average composition is m/n
= 70/50 (mole%), and according to GC-MS analysis, the cyclosiloxane mixture is mainly m-6゜n=1 (91.3wt%) + m=n=2 (4,7
wt%).

It consisted of m = 4, n = 1 (4, Owt%).

Reference Example 3 (Usage Example) 0.5 ml of a methanol solution (10 wt%) of tetramethylammonium hydroxide was added to 6.9 g of the cyclosiloxane mixture obtained in Example 1, and the mixture was heated at 110°C for 20 minutes under an argon gas stream. Heat for 1 minute to perform ring-opening polymerization, and
A viscous oil was obtained by adding 20 d of 0% hydrochloric acid solution in THF to stop the reaction. Extract this with ether and wash with water.

After drying, further heat at 200°C under reduced pressure of 0.5*iHg.
4.8 g of polysiloxane having a structure that removed unreacted cyclosiloxane by heating for 5 hours was obtained. N
According to MR measurements, its average composition is m/n-60/
40 (mole%).

183g of the polysiloxane thus obtained and p-bis(
By mixing 1.29 g of dimethylhydroxysilyl)benzene with 20 m/20 m of benzene, adding 0.1 g of tetramethylguanidine di-2-ethylhexoate as a catalyst, and azeotropically removing the produced water from the reaction solution. Dehydration polycondensation was performed.

After polymerizing for 19 hours, the reaction solution was diluted with 400ml of ethanol.
When reprecipitated, a white solid was obtained, which was filtered and dried to obtain 2.01 g of a copolymer having the following structure.

As a result of NMR measurement, the composition of the copolymer is p/mq/nq-
It was 25/45/30 (mole%). Also, according to GPC measurement, the weight average molecular weight of the copolymer was 15. lX10. The number average molecular weight was 7.80×10 and the degree of dispersion was 1.93.

Reference Example 4 (Usage Example) In the same manner as in Reference Example 3, 861 g of the cyclosiloxane mixture obtained in Example 2 was subjected to ring-opening polymerization to obtain polysiloxane 6, 85.9 having the following structure. According to NMR measurements, the average composition of polysiloxane is m/n
= 66/34 (mole%).

103g of the polysiloxane thus obtained and p-bis(
Copolymer 1, oOg having the structure was obtained by mixing 0.53 # of dimethylhydroxysilyl)benzene with 10 PA/ of benzene and performing dehydration polycondensation and purification in the same manner as in Reference Example 3.

As a result of NMR measurement, the composition of the copolymer is p/mq/nq=
It was 25/50/25 (mole%). Furthermore, as a result of GPC measurement, the weight average molecular weight of the copolymer was 10.2×10. The number average molecular weight was 4.72×10 and the dispersity was 2.16.

Reference Example 5 (Usage Example) Cyclosiloxane mixture t74 obtained in Example 3
0.5 g of activated clay was added to the mixture, and the mixture was heated and stirred at 120° C. for 1 hour under an argon gas stream to obtain a viscous oil. This oil was dissolved in 50 ml of ether, filtered, the ether was removed, and the unreacted cyclosiloxane was removed by heating at 200° C. for 2 hours under a reduced pressure of 0.5 wHg, resulting in a polysiloxane with the following structure: 1.
31.9 was obtained. According to NMR measurement, the average composition was m/n = 66/34 (mole%).

The polysiloxane 1.16.9 thus obtained and p-
Bis(dimethylhydroxysilyl)benzene 1, 29
g was mixed with 10 m/m of benzene and subjected to dehydration polycondensation and purification in the same manner as in Reference Example 3 to obtain 1.57 g of a copolymer having the following structure.

As a result of NMR measurement, the composition of the copolymer is p/mq/nq=
50/2B/22 (mole%), and as a result of GPC measurement, the weight average molecular weight of the copolymer was 21.5 x 104
The number average molecular weight was 7.06×10' and the dispersity was 302.

Reference Example 6 (Usage Example) 1.0 g of activated clay was added to 315 g of the cyclosiloxane mixture obtained in Example 4, and the mixture was heated for 12 hours under an argon gas stream.
When heated and stirred at 0°C for 3 hours, a viscous oil was obtained. This oil was dissolved in 50ml of ether, filtered, the ether was removed, and the unreacted cyclosiloxane was removed by heating at 200°C for 2 hours under a reduced pressure of 0.5 mmHg. ,
66 g was obtained. According to NMR measurement, its average composition is m/n = 58/42 (mole%).

The polysiloxane thus obtained was 1.661! Trubis(dimethylhydroxysilyl)benzene 1,35
g was mixed with 20 ml of benzene and subjected to dehydration polycondensation and purification in the same manner as in Reference Example 3 to obtain 150 g of a copolymer having the following structure.

As a result of NMR measurement, the composition of the copolymer is p/mq/n
q=40/35/25 (mole%),
Furthermore, as a result of GPC measurement, the weight average molecular weight of the copolymer was 1
The number average molecular weight was 4.46×10 and the dispersity was 3.03.

AtJ (example of use) 0.5 g of activated clay was added to 1.41 g of the cyclosiloxane mixture obtained on the day of the example, and the mixture was heated for 12 g under an argon gas stream.
After heating and stirring at 0°C for 4 hours, a viscous oil was obtained. After dissolving this oil in ether 504 and filtering it,
When the ether was removed and unreacted cyclosiloxane was removed by heating at 200°C for 2 hours under a reduced pressure of 3.5 m+iHg, a polysiloxane with the following structure was obtained: 0.8
7 g was obtained. According to NMR measurement, the average composition was m/n = 73/27 (mole%).

The thus obtained polysiloxane 0.87.9' and p-
Bis(dimethylhydroxysilyl)benzene 0,62
g was mixed with benzene 6d and subjected to dehydration polycondensation and purification in the same manner as in Reference Example 3 to obtain 112 g of a copolymer having the following structure.

As a result of NMR measurement, the composition of the copolymer is p/mq/nq=
39/47/14 (mole%), and as a result of GPC measurement, the weight average molecular weight of the copolymer was 15.2X1D4.
The number average molecular weight was B, 0OX10', and the dispersity was 1.90.

Reference Example Day The copolymers obtained in Reference Examples 3 to 7 were dissolved in benzene,
A 5% by weight solution was prepared. These solutions were cast onto a Teflon plate, and after the solvent was evaporated and dried, a thickness of 6 to 160 μm was formed.
A cast film was obtained. All of these films were strong films. This membrane was attached to a low-vacuum permeation test device, and the permeation rates of oxygen gas and nitrogen gas were measured. The temperature of the gas and membrane equipment was 25°C.

Table 1 shows the measurement results of the permeability coefficients of each gas.

Table 1

Claims (1)

[Scope of Claims] General formula (wherein, Substituted alkyl)silyl group, polyfluoroalkylmethyloxycarbonyl group'), l is 2-4. m and n represent positive integers, and m + n = 3~6°n/m is 02~50. ) A cyclosiloxane derivative represented by