JPH0465427A - Polysilane-polysiloxane block copolymer and production thereof - Google Patents

Abstract

PURPOSE:To obtain the title copolymer with constant block length, suitable for electronic materials, etc. by anoinic polymerization of a biphenyl-masked disilene adduct into a polysilane followed by additio of a cyclic siloxane and the carrying out ring opening polymerization. CONSTITUTION:Firstly, a biphenyl-masked disilene adduct of formula I (R<1> - R<4> are each alkyl, alkyl, etc.) is put to anoinic polymerization in the presence of an anionic species such as methyllithium as polymerization initiator. Thence, a cyclic siloxane of formula II (R<5> and R<6> are each H, alkyl, etc.; x is 3 - 5) is added to the system and ring opening polymerization is carried out, thus obtaining the objective block copolymer of formula III (m is >= 15; n is >=3).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a polysilane-polysiloxane blot copolymer and a method for producing the same. Target,
The present invention relates to polysilane-polysiloxane block copolymers that have physical properties and are useful as conductive materials, electronic materials such as photoresists, and optical functional materials, and methods for producing the same.

Conventional technology Conventionally, the method for producing high molecular weight polysilane is as follows:
The following methods have been proposed.

(a) Dimethyldichlorosilane in a benzene solvent for 1
Method for producing polydimethylsilane by Wurtz type condensation with metallic sodium at 15°C [Journal of American Chemical Society (J, 8m, C)
hem, Soc, ), Volume 71, 1949, 96
3-964 pages].

Me Mea CI-3i-CI-〉-+Si±+NaC]Me
A method for producing polysilane by anionic polymerization using a disilene adduct masked with Me(Ω)biphenyl as a monomer and methyllithium as a polymerization initiator (Japanese Patent Application Laid-Open No. 1-2306
Publication No. 38).

n-Bu Me (c) The present inventors also discovered that silicon anion species,
A method for producing polysilane using at least one anion species selected from oxygen anion species and fluorine anion species as a polymerization initiator has been proposed (Japanese Patent Application No. 1228633).

On the other hand, the following polysilane-polysiloxane copolymers and methods for producing the same have been proposed.

(d) A halogen-terminated polysilane-siloxane oligomer is produced by a condensation reaction in the presence of lithium using dichlorosilane and a halogenated disiloxane, and then a halogen-terminated polysilane-siloxane oligomer is produced by a condensation reaction in the presence of sodium using the halogen-terminated oligomer. Polysilane-siloxane copolymer and method for producing the same (Japanese Unexamined Patent Application Publication No. 1988-6264830)
etc.

Problems to be Solved by the Invention However, the above manufacturing method has the following problems. In other words, in the method of producing polysilane using the Wurtz condensation method of chlorosilanes in the presence of an alkali metal, it is difficult to control the molecular weight of the resulting polysilane, and the structure of the polymer end is unclear, resulting in a polysilane with a desired chain length. The problem was that it was extremely difficult to produce a block copolymer with another polymer chain at the end of the block copolymer.

In addition, a halogen-terminated polysilane-siloxane oligomer is produced by a condensation reaction in the presence of lithium using dichlorosilane and a halogenated disiloxane, and then the halogen-terminated oligomer is used) The method for producing polysilane-siloxane copolymers only yields copolymers with a structure in which short polysilane buttons and short polysiloxane chains are connected; therefore, open blocks in which long polysilane buttons and long polysiloxane chains are connected are obtained. The problem has been that it is difficult to produce a polysilane-polysiloxane block copolymer having this structure.

The present invention is an attempt to solve the problems associated with the prior art as described above, and is to create a true polysilane-polysiloxane in which polysilane chains of a desired length and polysiloxane chains of a desired length are alternately bonded. The object of the present invention is to provide a block copolymer and a method for producing the same.

Means for Solving the Problems Summary of the Invention In general, the useful electrical and photochemical properties of polysilane, such as conductive properties and ultraviolet absorption properties, are derived from the delocalization of silicon-silicon bonds in the main chain. Therefore, the length of the continuous silicon chain has a great effect on the properties of polysilane, and the ratio of the length of the polysilane chain to the length of the polysiloxane chain determines the properties, solubility, water repellency, oil repellency, etc. of the resulting copolymer. Known to affect mechanical and physical properties.

The present inventors investigated various polysilane-polysiloxane block copolymers having a polysilane chain of a desired length and a polysiloxane chain of a desired length, and a method for producing the same. After producing polysilane by anionic polymerization of a disilene adduct, a cyclic siloxane compound is added and ring-opening polymerization is performed to produce a polysilane chain having a desired length and a polysilane bonded with a polysiloxane chain having a desired length. The inventors discovered that it is possible to produce a polysiloxane block copolymer and completed the present invention. That is, the present invention provides: (1) A polysilane-polysiloxane block copolymer represented by the following general formula [■].

(In the formula, R1, R2, R3, and R4 are alkyl groups or aryl groups, and may be different or the same, and R5 and R6 are hydrogen atoms, alkyl groups, or aryl groups, and may be different, respectively. (m is an integer exceeding 15, and n is an integer exceeding 3.) and (2) a biphenyl-masked disilene adduct RI represented by the following general formula [11]. The R30 copolymer is represented by the following general formula [13].

(In the formula, R1, R2, R3 and R4 have the same meanings as above.

) was used as a polymer to produce polysilane by anionic polymerization, and then a cyclic siloxane compound bis expressed by the following general formula [III] (wherein R5 and R6 have the same meanings as above, and X is 3
It is an integer of ~5. ) is added to carry out ring-opening polymerization [I
This invention relates to a method for producing a polysilane-polysiloxane block copolymer represented by the following.

Polysilane-polysiloxane copolymer The polysilane-polysiloxane copolymer according to the present invention (wherein R
1, R2, R3 and R4 are alkyl groups or aryl groups, which may be different or the same, and R5 and R6 are hydrogen atoms, alkyl groups or aryl groups, which may be different or the same. good. Also, m
is an integer greater than 15, and n is an integer greater than 3. ) In the above formula [I], m is an integer exceeding 15, preferably an integer exceeding 25.

This is because when the length of the silicon chain is approximately 50 mm or more, the silicon-silicon bond becomes sufficiently conjugated, and the electrical and
This is to improve optical properties by +1. Although there is no clear upper limit for m, if the molecular weight is too high, the solubility in a solvent will decrease, making handling difficult, so m is preferably an integer between ioo and ooo.

Preferably, n is an integer greater than 3 and less than 10.000. Moreover, it is preferable that m/n is 0.1-10, and it is more preferable that it is 0.2-5. This is because if the amount of either comonomer is extremely large, the properties of the smaller comonomer will not be expressed. The molecular weight of the polysilane-polysiloxane block copolymer is 1
．． It is preferable that it is 000 or more and 1,000.000 or less.

The polysilane-polysiloxane block copolymer described above can be used in applications expected of polysilane, such as photoresists, photoconductive materials, and nonlinear optical materials. Among these, when used as a photoresist, the photoreactivity of polysilane is exhibited during exposure, and the oil repellency and low swelling properties of polysiloxane are exhibited during etch lag, so it is particularly preferable.

Disylene adduct In the present invention, a biphenyl-masked disylene adduct represented by the general formula [■] is used as a raw material for producing polysilane in the -th stage reaction.

(In the formula, R1, R2, R1 and R4 are an alkyl group or an aryl group, and may be different or the same.) In general, disylene having a silicon-silicon double bond is an unstable compound. Generally, a disylene adduct masked with biphenyl or the like represented by the general formula [n] is used as a monomer for anionic polymerization, but it has chemical properties such as a compound represented by the general formula [IIE]. The compound represented by the above general formula [■] is, for example, a journal
of American Chemical Society (J,A
m, Chem, Soc,), Volume 94, 1972,
It can be easily synthesized by the method described on pages 5837-5841. That is, for example, in a mixed solution of biphenyl and lithium metal, 1,1.
After adding 2.2-tetramethyl-1,2-dichlorosilane solution and reacting, purification yields 1-phenyl-7,7,8,8-tetramethyl-7,8-disilabicyclo[2,2 , 2E octa-2,5-diene can be synthesized.

Specifically, the sidilene adduct represented by the above general formula [II] is 1-phenyl-7°8-dimethyl-7
,8-di-n-propyl-7゜8-disilabicyclo[2
,2,2]octa-2゜5-diene, 1-phenyl-7
,7,8,8tetramethyl-7,8-disilabicyclo[
2゜2.2] Octa-2,5-diene, 1-phenyl-
7,8-dimethyl-7,8-di-n-hexyl roof, 8
-disilabicycloC2,2,2]octa-2,5-diene, 1-phenyl-7゜7.8-)dimethyl-3-n-
Butyl-7,8-disilabicyclo[:2.2.2E octa-2゜5-diene, 1.8-diphenyl-7,7,8
=trimethyl-7,8-disilabicyclo[2°2.2]
Octa-2,5-diene, 1-phenyl-7,7,8-
) dimethyl-8-”(p-methoxyphenyl)-7,8
-disilabicyclo[2°2.2]octa-2,5-diene and the like.

Polymerization initiator In the present invention, when anionically polymerizing the disylene adduct as described above, at least one anion species selected from carbon anions, silicon anions, oxygen anions, and fluorine anions is used as a polymerization initiator. used as.

Carbon anion species The carbon anion species used in the present invention has the following general formula [
rV].

R19... [■] (In the formula, R7 is an alkyl group or an aryl group.) In addition, the carbon anion species is a monovalent cation, such as an alkali metal ion, an alkaline earth metal monohalide ion, etc., as a counter ion. That is.

Specifically, the compounds that generate the above carbon anion species in the reaction system include methyllithium, ethyllithium, n
-propyllithium, i-propyllithium, n-butyllithium, 1-butyllithium, t-butyllithium,
Examples include phenyllithium, methylmagnesium bromide, ethylmagnesium bromide, n-propylmagnesium pro-mite, i-propylmagnesium bromide, n-butylmagnesium bromide, 1-butylmagnesium bromide, t-butylmagnesium bromide, phenylmagnesium bromide, etc. .

Silicon anion species The silicon anion species used in the present invention has the following general formula C
It is an anionic species represented by V'l.

R'-5ie [VE
IG (In the formula, R', R' and RIG are hydrogen atoms, alkyl groups or aryl groups, and may be different or the same.) In addition, the silicon anion species is a monovalent cation, such as an alkali metal ion, ammonium ion, etc. as a counter ion.

Specifically, the compounds that generate the above silicon anion species in the reaction system include triphenylsilylpotassium, triphenylsilyl sodium, triphenylsilyllithium, diphenylmethylsilylpotassium, diphenylmethylsilyl sodium, diphenylmethylsilyllithium,
Examples include phenyldimethylsilyl potassium, phenyldimethylsilyl sodium, phenyldimethylsilyl lithium, trimethylsilyl potassium, trimethylsilyl sodium, trimethylsilyl lithium, diphenylhydrosilyllithium, and trihydrosilyl potassium.

Oxygen anion species The oxygen anion species used in the present invention has the following general formula [
VI].

R''Oe[VI'l (In the formula, R1+ is a hydrogen atom, an alkyl group, a silyl group, or a silyl group.) In addition, the oxygen anion species is a monovalent cation such as an alkali metal ion, an ammonium ion, etc. It is used as a counter ion.

Specifically, the compounds that generate the above oxygen anion species in the reaction system include potassium t-butoxide, sodium methoxide, sodium ethoxide, potassium methoxide, tetra-n-butylammonium hydroxide, Examples include lithium triphenylsilate and lithium trimethylsilate.

Fluorine Anion Species The fluorine anion species used in the present invention have monovalent cations such as alkali metal ions, ammonium ions, etc. as counter ions.

Specific examples of the compound that generates the above-mentioned fluorine anion species in the reaction system include tetra-n-butylammonium fluoride, lithium fluoride, potassium fluoride, and cesium fluoride.

Grooved siloxane compound In the present invention, the above-mentioned biphenyl-masked disylene adduct is used as a monomer, and after anionic polymerization is performed with the above-mentioned polymerization initiator to produce polysilane, the general formula [III] is added to the reaction system. A cyclic siloisan compound represented by is added, and anionic polymerization is continued to produce a polysilane-polysiloxane block copolymer.

(In the formula, R3 and R6 are a hydrogen atom, an alkyl group, or an aryl group, and X is an integer of 3 to 5.) Specifically, the cyclic siloxane compound represented by the above general formula [III] is: Hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, hexaethylcyclotrisiloxane, octaethylcyclotetrasiloxane, hexaphenylcyclotrisiloxane,
Examples include octaphenylcyclotetrasiloxane, trimethylcyclotrisiloxane, trinotyltriphenylcyclotrisiloxane, and tetramethylcyclotetrasiloxane, among which hexamethyltrisiloxane where X is 3, hexaethyltrisiloxane, hexaphenylcyclo Trisiloxane, trimethylcyclotrisiloxane, trinotyltriphenylcyclotrisiloxane, and the like are preferred because they provide a polysilane-polysiloxane block copolymer with a narrower molecular weight distribution.

Anionic polymerization reaction When trialkylsilyl lithium is used as a polymerization initiator and trimethylsilyl chloride is used as a polymerization terminator, the anionic polymerization reaction of the present invention proceeds as shown in the following formula, and the polysilane-polysiloxane block co-exists. It is thought that a polymer is produced.

The anionic polymerization reaction of the present invention is preferably carried out in an atmosphere of an inert gas such as nitrogen, helium, or argon, and in the absence of oxygen and/or water in the reaction system.

When oxygen and/or water are present in the reaction system, the silicon-silicon bond of the disylene adduct is easily oxidized and cleaved. Also,
The growing end of polysilane and/or polysiloxane undergoes a termination reaction by reaction with oxygen and/or water,
As a result, a polysilane-polysiloxane block copolymer having the desired molecular weight cannot be obtained.

The polymerization reaction may be performed under normal pressure or under reduced pressure. Further, the reaction temperature and reaction time are desirably -196 to 50°C, preferably -78 to 20°C during the anionic polymerization reaction of polysilane, and 30 minutes to 2 hours is usually sufficient.

In addition, the reaction temperature and reaction time during the copolymerization reaction of polysiloxane are -30 to 30°C, preferably -10 to 20°C.
It is desirable that the time is 10 to 20 hours, and usually 10 to 20 hours is sufficient.

The amount of carbon anion species, silicon anion species, oxygen anion species, or fluorine anion species that are polymerization initiators added to the disylene adduct is usually 0.0 per mole of the disylene adduct.
It is desirable to use it in an amount of 0.001 to 10 mol, preferably 0.001 to 1 mol.

The molecular weight, that is, the polymer chain length, of the polysilane and/or polysiloxane of the present invention can be arbitrarily controlled by adjusting the molar ratio of the polymerization initiator used and the disilene adduct and/or the cyclic siloxane compound added.

That is, when the molar ratio of the polymerization initiator and the disilene adduct and/or the cyclic siloxane compound is increased, the molecular weight of the polysilane and/or polysiloxane obtained becomes smaller; The molecular weight of increases.

As the reaction solvent, any polar or non-polar solvent can be used as long as it dissolves both the disylene adduct and the cyclic siloxane compound, but aprotic polar solvents such as ether and tetrahydrofuran should be used. is preferred.

In addition, in the method for producing a block copolymer of the present invention, not only does the polymerization of polysiloxane be directly initiated using the active end of polysilane, but also, after the polymerization of polysilane, for example, an epoxide compound is added, and then a cyclic siloxane compound is added. By doing so, it is also possible to bond the polysilane chain and the polysiloxane chain via the ethylene oxide unit. Furthermore, in the method for producing a block copolymer of the present invention, after producing the polysilane-polysiloxane block copolymer, a highly reactive third monomer such as a silylated olefin or an epoxide compound is added, or a disilene addition ABC type (A: polysilane, B:
Polysiloxane, C: IK3 polymer) or ABA
It is also possible to produce block copolymers such as type B.

Effects of the Invention The polysilane-polysiloxane block copolymer of the present invention has desired electrical, optical properties, mechanical, and physical properties because the chain lengths of the polysilane chain and polysiloxane chain are each independently controlled. Polysilane with both
Polysiloxane block copolymer, conductive material,
Electronic materials? It is useful as a photofunctional material.

Further, in the method for producing a polysilane-polysiloxane block copolymer according to the present invention, the chain lengths of the polysilane chain and the polysiloxane chain can be controlled independently, and
A polysilane-polysiloxane block copolymer having a high molecular weight and a well-defined block structure can be produced.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 Under a stream of dry nitrogen, 1-phenyl-7,7,8-trimethyl-8-n-butyl-7,8-disilabicyclo[2,2
, 2] A solution of 2.0 mmol of octa-2,5-diene (1) dissolved in 10 bottles of tetrahydrofuran was cooled to -78°C in a dry ice-methanol bath. Into this solution, under stirring, n-butyllithium, which is a polymerization initiator, was added 0.
．． After adding 0.01 mmol of IJ mole, the mixture was removed from the bath and allowed to warm up to room temperature to carry out anionic polymerization of polysilane.

After 1 hour, a portion of the reaction solution was collected and analyzed using a gas chromatograph to determine the disappearance of (1) and the production of biphenyl! It was Li. GPC measurement shows that the number average molecular weight (MO) in terms of polystyrene (hereinafter the same) is 1. IX, 10', and a polysilane having a weight average molecular weight (~) of 1.6 X 10' was produced.

Next, the reactor was immersed in a water bath, and under stirring, a solution of 1.5 mmol of hexamethylcyclotrisiloxane (2) dissolved in 1-tetrahydrofuran was added to carry out a polysiloxane polymerization reaction at 0°C.

After 40 hours, the disappearance of (2) was confirmed by gas chromatography, and then one drop of trimethylsilyl chloride was added to stop the polymerization reaction. In the GPC measurement at this time, Mo was 4.5% in the polymer region. I X 10' and ~ is 7
．． A single peak, OX 10', was observed.

The solvent was distilled off from the reaction solution, the residue was redissolved in benzene,
After removing the salt by washing with water, the solution was added to a large excess of methanol to precipitate the polymer. After removing the supernatant, the solvent was distilled off to obtain 0.47 g of a white, highly viscous oil.

When the UV spectrum of this polymer (hexane solvent) was measured, maximum absorption attributable to polysilane chains was observed at 306 nm. 1.000-1 in IR spectrum
．． 81 of the polysiloxane chain over 100 cm-'
Absorption attributed to -0 stretching vibration was observed. Also,
'H-NMR spectrum (deuterated chloroform solvent) shows that polysilane and polysiloxane have a concentration of 5% at 0.6 ppm.
The signal of i-CH3 group is 0.4 to 1.6 ppm in 5i-C,H of polysilane.

Signals of the polysilane group were observed, and the ratio of polysilane group to polysiloxane group calculated from these integral ratios was 1:2.9.

The molecular weight increased after the addition of (2), the GP of the product
C shows a single peak, the product UV, IR,
'H-NliR spectrum suggests the presence of both polysilane and polysiloxane, and repeated reprecipitation purification does not change the above results. It was confirmed that it was a block copolymer bonded to

In addition, the IR spectrum and '
) The results of the I-NMR spectra are shown in FIGS. 1 and 2, respectively.

Example 2 Using 0.01 mmol of potassium t-butoxide as a polymerization initiator, 5.2 mmol of (1) and 1 mmol of (2)
．． 5 Mi! An anionic polymerization reaction was carried out in the same manner as in Example 1 except that J mol was used.

In the GPC measurement before addition of (2), Mn was 2.9 x 1
0' and the rod was 4.6 x 10', but (
After the addition and disappearance of 2), Mo is 6. OX10
' was increased to 10,8 X 10'. Reprecipitation purification was carried out in the same manner as in Example 1, and 0.87 g of a white, ladle-like polymer was obtained. 'H-NM
From the integral ratio of the R spectrum, it was found that the ratio of polysilane chains to polysiloxane chains in this polymer was 1:1.1.

Example 3 The same procedure was carried out except that 0.05 mmol of tetra-n-butylammonium fluoride was used as a polymerization initiator, 4.9 mmol of (1) and 0.8 mmol of (2) were used. An anionic polymerization reaction was carried out in the same manner as in Example 1.

In the GPC measurement before addition of (2), Mn was 5.4X10'
The Mn was 7.6 x 10', but after the addition and disappearance of (2), the Mn was 9.2 x 10', and the Mn increased to 16, OX 10'. Reprecipitation purification was carried out in the same manner as in Example 1, and 0.69 g of a white elastomeric polymer was obtained. 'H-NM
From the integral ratio of the R spectrum, it was found that the ratio of polysilane button to polysiloxane button of this polymer was 1:0.63.

Example 4 Phenyldimethylsilyllithium was used as a polymerization initiator.
01 mmol of 1,8-diphenyl-7,7,8-)limethyl-7,8-disilabicycloC2,22]octa-2,5-diene (3) as a disylene adduct.
．． 0 mmol and 1,3 as a cyclic siloxane compound
．． An anionic polymerization reaction was carried out in the same manner as in Example 1, except that 1.3-: IJ mol of 5-)limethyl-1,3,5-)riphenylcyclotrisiloxane (4) was used.

GPC measurement before addition of (4) shows that gn is 2.5 x 1
0' and one is 4. I x 10', but
After addition and disappearance of (4), Mn is 7.8X10',
I'Sw increased to 12.9x104. Reprecipitation purification was carried out in the same manner as in Example 1, and 1.1 g of a white elastomeric polymer was obtained. 'The integral ratio of the H-NMR spectrum reveals that the polysilane composition of this polymer:
The ratio of polysiloxane chains was found to be 1:0.50.

Example 5 Using 0.01 mmol of phenyllithium as a polymerization initiator, 5.0 mmol of (3) was added. 1 mol and 1.3.5-)limethyl 1.3.5-trihydrotrisiloxane (5) as a cyclic siloxane compound. An anionic polymerization reaction was carried out in the same manner as in Example 1 except that J mol was used.

In CPC measurement before addition of (5), 1ion was 2.7
10' and the rod was 4.2 x 10', but (5
) after addition and disappearance, Mo゛ is 5. I x 10
' and ~ increased to 8.2X10'. Reprecipitation purification was carried out in the same manner as in Example 1, and 0.79 g of a white starch syrup-like polymer was obtained. ) It was found from the integral ratio of the I-NMR spectrum that the ratio of polysilane chains to polysiloxane chains in this polymer was 1:0.59.

[Brief explanation of drawings]

FIG. 1 shows an IR spectrum of the polysilane-polysiloxane block copolymer obtained by measurement in Example 1 of the present invention, and FIG. 2 similarly shows an 'H-NMR spectrum.

Claims (2)

[Claims] (1) A polysilane-polysiloxane block copolymer represented by the following general formula [I]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...[I] (In the formula, R^1, R^2, R^3 and R^4 are alkyl groups or aryl groups, even if they are different. R^5 and R^6 are a hydrogen atom, an alkyl group, or an aryl group, and may be different or the same. Also, m is an integer exceeding 15, and n
is an integer greater than 3. ) (2) Biphenyl-masked disylene adduct represented by the following general formula [II]▲There are mathematical formulas, chemical formulas, tables, etc.▼... [II] (In the formula, R^1, R^2, R^ 3 and R^4 have the same meanings as above) as a monomer, and after producing polysilane by anionic polymerization, a cyclic siloxane compound represented by the following general formula [III] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼・...[III] (In the formula, R^5 and R^6 have the same meanings as above, and X
is an integer from 3 to 5. ) is added to cause ring-opening polymerization [
A method for producing a polysilane-polysiloxane block copolymer represented by I].