JPH0686506B2 - Novel method for producing polysilane block copolymer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a polysilane block copolymer.

[Description of Prior Art]

Regarding polysilane, it has been reported that it is insoluble in solvents [The Journal of American Chemical Society (The Journal of American Chemical
Society), 125 , 2291 pp (1924)], and in recent years, it has been reported that polysilane is solvent-soluble and film formation is possible [The Journal of American Ceramic Society (The Journal of Ame
rican Ceramic Society), 61 , 504pp (1978)].
Further, since polysilane causes photodecomposition upon irradiation with ultraviolet rays, research on application to resist has been reported [JP-A-60-984].
31 gazette, JP-A-60-119550 gazette].

In addition, polysilane has been reported to have the property of an optical semiconductor in which charges can be transferred by the σ-bond of the main chain [Physical Review,
B 35, 2818 pp (1987)].

From these reasons, application of polysilane to electrophotographic photoreceptors is expected, but for obtaining electrophotographic photoreceptors that are practically useful by using polysilane as a photoconductive material, the polysilane compound is It is required to satisfy at least such requirements. That is, (i)
In addition to being solvent-soluble and capable of forming a film, it is possible to form a film without fine defects and a film with high homogeneity. (Ii) Since a fine defect is not allowed in an electrophotographic photoreceptor. The structure of the substituents is also clear, and the quality is high, which does not cause abnormalities in film formation.

By the way, polysilane is a film which is fragile in terms of mechanical properties because it is structurally easy to have a one-dimensional structure (see Solid State Ph.O. Vo122, No. 11, page 907 (1987)). That is, since polysilane is hard and brittle, heat shrinkage occurs during film formation,
It is vulnerable to cracking and bending, has poor contact properties, and is susceptible to peeling. Further, if there is a contact substance on the surface, it is easily scraped and the wear resistance is poor.

There have been some reports on the synthesis of polysilane compounds, but all of these reported polysilanes are insufficient for use in electrophotographic photoreceptors. That is, as a low molecular weight polysilane,
It has been reported that all Si groups have organic groups substituted [The Journal of American Chemical
Society (Journal of American Chemical Societ
y), 94 , (11), 3806pp (1972) and JP-B-63-38033
No. publication].

The one described in the former publication has a structure in which the terminal group of dimethylsilane is substituted with a methyl group, and the one described in the latter publication has a structure in which the terminal group of dimethylsilane is substituted with an alkoxy group. However, both have a degree of polymerization of 2 to 6
And does not show the characteristics of polymers. That is, because of its low molecular weight, it does not have a film-forming ability as it is, and it is difficult to industrially use it. A high molecular weight polysilane having a structure in which all Si groups are substituted with organic groups has recently been reported [see Nikkei New Material, August 15, page 46 (1988)]. However, since it passes through a special reaction intermediate, the synthetic yield is expected to decrease, and industrial mass production is difficult.

In addition to the above report, a synthesis method of polysilane has been reported [The Journal of Orcanometallic.
Chemistry (The Journal of Organometallic Chemis
try), 198pp, C27 (1980), or The Journal of Polymer Science, Polymer
Chemistry Edition), Vol, 22, 159-170 pp (1984)].

However, all of the reported synthetic methods are only condensation reactions of the polysilane main chain, and there is no mention of the terminal groups. In any of the synthesis methods, unreacted chloro groups and by-products are produced by side reactions, and it is difficult to constantly obtain the desired polysilane compound.

Also, a polysilane block copolymer has been recently reported [Chemicals and Industry, 42 , No. 4, 744 (1989)],
It has been announced that the reaction does not proceed with other monomers using only the block copolymer of methylmethacrylate (The 58th Annual Meeting of the Chemical Society of Japan 2IJ28).

Further, some examples of using the above polysilane as a photoconductor have been reported (US Pat. No. 4,618,551).
Specification, U.S. Pat.No. 4,772,525, JP-A-62-26
9964), it is considered that there are unreacted chloro groups and by-products due to side reactions.

That is, according to U.S. Pat.No. 4,618,551, the above-mentioned polysilane is used as an electrophotographic photoreceptor, but image formation by the electrophotographic photoreceptor has an applied potential of 500 to 500 in the case of a general copying machine. While 800V is sufficient, the applied potential is abnormally high, that is, 1000V. It is considered that this is to solve the problem that, at a normal potential, a structural defect of polysilane causes a defect in the electrophotographic photosensitive member, and speckled abnormal development occurs in the obtained image. Further, according to JP-A-62-269964, a photoconductor for electrophotography is produced by using the above-mentioned polysilane and the photosensitivity is measured. However, the photosensitivity is slow, and the known selenium photoconductor is known. It is understood that it does not have any advantages over organic photoreceptors.

Further, according to U.S. Pat.No. 4,772,525, the polysilane is used as an electrophotographic photoreceptor,
It has been reported that cracks are likely to occur in a solvent. And in the specification, the molecular weight of polysilane is increased to improve the solvent resistance, but in this method, the mechanical properties originally possessed by polysilane cannot be improved, and hardness, brittleness, and adhesion are not improved. It is considered that the defect and abrasion resistance are not improved.

As described above, the conventional polysilane is not industrially applicable, leaving many problems in order to use it in the electrophotographic photoreceptor.

[Object of the Invention]

A main object of the present invention is to provide a novel method for producing a polysilane block copolymer composed of a polysilane block and a vinyl polymer block.

Another object of the present invention is to provide a method for producing a polysilane block copolymer having excellent mechanical properties, toughness, good adhesion, and excellent wear resistance.

Still another object of the present invention is to provide a method for producing a polysilane block copolymer having good solvent solubility and excellent film forming ability.

Still another object of the present invention is to provide a method for producing a polysilane block copolymer useful for producing various electronic devices, medical equipment and the like.

[Structure of Invention]

The present invention is to achieve the above-mentioned object, and the gist thereof is polysilane characterized by photoinitiating polymerization of a vinyl-based monomer with polysilane by irradiation with light having a wavelength of absorption maximum wavelength or more of polysilane. It is a method for producing a block copolymer.

The polysilane block copolymer composed of the polysilane block and the vinyl polymer block provided by the production method of the present invention has excellent mechanical properties, has toughness, good adhesiveness, and excellent abrasion resistance, Non-toxic, aromatic solvents such as toluene, benzene, xylene, dichloromethane, dichloroethane, chloroform,
It is easily soluble in halogenated solvents such as carbon tetrachloride and other solvents such as tetrahydrofuran (THF) and dioxane.
It has an excellent film forming ability. The film formed with the polysilane block copolymer according to the production method of the present invention is uniform and has a uniform film thickness, and has excellent heat resistance.

From the above, the polysilane block copolymer provided by the production method of the present invention is a polymer substance which can be used for production of electronic devices, medical equipment and the like and has high industrial utility value.

Examples of the electronic device include organic photoconductors, electric conductors, photoresists, optical information storage elements, and the like. In addition, as the above-mentioned medical equipment, artificial organs and blood vessels,
Examples include blood transfusion bags.

Next, the novel method for producing the polysilane block copolymer of the present invention will be described in detail.

The present invention is characterized in that a vinyl monomer is photoinitiated with polysilane by irradiation with light having a wavelength not less than the absorption maximum wavelength of polysilane.

The photo-initiated reaction of vinyl-based monomers with polysilane is described in US Pat.No. 4,569,953, but since the photo-initiated reaction is carried out by irradiation with light having a wavelength smaller than the absorption maximum wavelength of polysilane, polymerization of vinyl groups is However, all polysilanes are decomposed. Therefore, the characteristics of polysilane are lost in the produced polymer.

In the present invention, as a result of extensive studies aimed at improving the physical properties of polysilane, it was found that the photoinitiated polymerization can be carried out without lowering the molecular weight of polysilane by carrying out a photoinitiated reaction by irradiation with light having an absorption maximum wavelength of polysilane or more. .

One aspect of the method for producing the polysilane block copolymer of the present invention will be described below.

First, polysilane, a vinyl-based monomer, and an appropriate solvent are prepared. The polysilane is preferably highly pure and free of siloxane residues.

Further, the vinyl-based monomers used include styrene-based, acrylic-based, vinyl acetate-based, and butadiene-based monomers.

Examples of the styrene-based monomer include styrene and α-
Methyl styrene and divinyl benzene are mentioned.

Examples of acrylic monomers include methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, tert-butyl methacrylate, and n.
-Propyl methacrylate, n-octyl methacrylate and the like can be mentioned.

Examples of vinyl acetate-based monomers include vinyl acetate,
Examples thereof include vinyl propionate and vinyl butyrate.

Examples of the budadiene-based monomer include butadiene,
Examples include isoprene and chloroprene.

When a commercially available vinyl-based monomer is used, it needs to be purified by distillation because it contains a polymerization inhibitor.

Further, as the solvent, it is necessary to use one that is compatible with both the polysilane and the vinyl-based monomer. For example, benzene, toluene, an aromatic solvent such as xylene,
Tetrahydrofuran, dioxane and the like are preferred. A halogen-based solvent has good solubility, but is not preferable because it suppresses polymerization.

Next, charge the polymerization tube with polysilane, vinyl monomer, and solvent, cool with liquid nitrogen, degas in a vacuum line, repeat this operation to remove oxygen from the reaction system, and then seal the polymerization tube. To do.

The charging ratio of the polysilane to the vinyl-based monomer is such that the ratio of the number of moles of the polysilane monomer to the number of moles of the vinyl-based monomer is 3: 7 to 9: 1, particularly 4: 6 to 8: 2.
It is preferable that

It is preferable to add an appropriate amount of the solvent so that the polysilane and the vinyl monomer are completely mixed.

Next, the polymerization tube charged with polysilane, a vinyl-based monomer and a solvent is heated to 50 to 90 ° C. in a constant temperature bath, and photoinitiated polymerization is performed by irradiation with light having a wavelength not less than the absorption maximum wavelength of polysilane.

The irradiation light has a wavelength of not less than the absorption maximum wavelength of polysilane, and exposure at a wavelength of not less than 10 nm and not more than 50 nm from the absorption maximum wavelength of polysilane is particularly preferable. The exposure time is appropriately determined depending on the light amount, but is usually about 10 seconds to 5 minutes.

The exposure light source may be any light source containing ultraviolet light,
For example, a mercury lamp, a fluorescent lamp, a hydrogen lamp, or a deuterium lamp is used. In this case, it is necessary to remove light having a wavelength smaller than the maximum absorption wavelength of polysilane with an ultraviolet absorption filter. As the ultraviolet absorption filter, for example, SC-37 (manufactured by Fuji Film) UV-D36A, UV-33
(Made by Toshiba) and the like.

After exposure, keep the temperature of the polymerization tube in a constant temperature bath at 50-90 ° C.
Polymerize for 30 minutes to 5 hours with shaking. After the polymerization, the polymerization tube is opened and the contents are diluted with the solvent. The obtained solution is reprecipitated using a solvent that does not dissolve the polymer but dissolves the monomer, to purify the polymer. As the reprecipitation solvent, alcohols such as methanol and ethanol, paraffinic solvents such as n-hexane and cyclohexane, ether solvents such as diethyl ether and dibutyl ether, and ester solvents such as ethyl acetate and butyl acetate are used.

The novel polysilane block copolymer composed of the polysilane block and the vinyl polymer block used in the present invention is exemplified below.

The composition of the block copolymer is A-, where A is the polysilane block and B is the vinyl-based polymer block.
Any configuration such as B, A-B-A, B-A-B, A-B-A-B may be used.

However, when two or more silane monomers are contained in the polysilane block, the silane monomers may be randomly copolymerized in the polysilane block.

The ratio of the total number of moles of the monomers of the polysilane block to the number of moles of the monomers of the vinyl polymer block in the polysilane block copolymer is 3 to 7 to 9 to 1, and in particular, 4 to 6 to 8 in particular. Pair 2 is preferred.

The polysilane block copolymer has a weight average molecular weight of 6000 to 1000000, preferably, more preferable from the viewpoint of solubility in a solvent and film forming ability, a weight average molecular weight of 8000 to 200,000,
The optimum one has a weight average molecular weight of 10,000 to 120,000.

Regarding the weight average molecular weight, those having a weight average molecular weight of 6000 or less do not show the characteristics of the polymer and have no film forming ability.
On the other hand, if the amount is 1,000,000 or more, the solubility in a solvent is poor, and it is difficult to form a desired film.

The blocks of the block copolymers used in the present invention are polysilanes based on The Journal of Organometalli
Chemistry), 198pp, C27 (1980) or The Journal of Polymer Scienc.
e, Polymer Chemistry Edition), Vol.22, 159pp (1984)
It is synthesized by the method described in. A particularly preferred polysilane is shown in general formula (I).

[Wherein R ₁ is an alkyl group having 1 or 2 carbon atoms, R ₂ is an alkyl group having 3 to 8 carbon atoms, a cycloalkyl group, an aryl group or an aralkyl group, and R ₃ is an alkyl group having 1 to 4 carbon atoms. The group R ₄ represents an alkyl group having 1 to ₄ carbon atoms. A and A ′ are each an alkyl group having 4 to 12 carbon atoms,
A cycloalkyl group, an aryl group or an aralkyl group, both of which may be the same or different. X and Y represent polymerized units of the monomer. The polysilane represented by the above general formula (II) can be synthesized as follows. That is, in a high-purity inert atmosphere deprived of oxygen and water, a dichlorosilane monomer is brought into contact with a condensation catalyst composed of an alkali metal to carry out halogen desorption and polycondensation to synthesize an intermediate polymer. Is separated from unreacted monomers, and the polymer is reacted with a predetermined halogenated organic reagent in the presence of a condensation catalyst composed of an alkali metal to condense an organic group at the terminal of the polymer.

In the above synthetic operation, the starting material dichlorosilane, the intermediate polymer, the halogenated organic reagent, and the alkali metal condensation catalyst are all highly reactive with oxygen and water, and therefore oxygen and water are present. The desired polysilane cannot be obtained under the atmosphere.

Therefore, it is necessary to carry out the above-mentioned operation for obtaining the desired polysilane in an atmosphere in which neither oxygen nor water exists. For this reason, it is necessary to pay attention to all the reaction vessels and reagents used so that neither oxygen nor water exists in the reaction system. For example, with respect to the reaction vessel, vacuum suction and argon gas substitution are performed in the blow box to prevent adsorption of water and oxygen into the system. In any case, the argon gas used is first passed through a silica gel column for dehydration, then passed through a column heated with copper powder at 100 ° C. for deoxygenation, and used.

The dichlorosilane monomer as a starting material is introduced into the reaction system after vacuum distillation is performed using the above-described argon gas that has been deoxygenated immediately before the introduction into the reaction system.
The halogenated organic reagent for introducing a specific organic group and the solvent to be used are also deoxygenated in the same manner as the dichlorosilane monomer and then introduced into the reaction system.
The deoxidizing treatment of the solvent is performed by vacuum distillation using the deoxygenated argon gas described above, and then further dehydrating treatment with metallic sodium.

When the condensation catalyst is used in the form of wires or chips, the wires or chips are used in an oxygen-free paraffinic solvent to prevent oxidation.

The dichlorosilane monomer as a starting material used for producing the polysilane represented by the general formula (I) used in the present invention is a silane compound represented by the general formula: R ₁ R ₂ SiCl ₂ described later or a combination thereof. A silane compound represented by the formula: R ₃ R ₄ SiCl ₂ is selectively used.

In the above-mentioned condensation catalyst, an alkali metal capable of decomposing a halogen to bring about a condensation reaction is preferably used, and specific examples of the alkali metal include lithium, sodium and potassium, of which lithium and sodium are preferable.

The above-mentioned halogenated organic reagent is for introducing the substituents represented by A and A ', and comprises a halogenated alkyl compound, a halogenated cycloalkyl compound, a halogenated aryl compound and a halogenated aralkyl compound. A suitable compound selected from the group: the general formula: A-
X and / or the general formula: A′-X (where X is Cl or Br), and an appropriate compound in the specific examples described later is selectively used.

The dichlorosilane monomer represented by the general formula: R ₁ R ₂ SiCl ₂ or this and the general formula: R ₃ R ₄ SiCl ₂ used for synthesizing the above-mentioned intermediate polymer is dissolved in a predetermined solvent to form a reaction system. When introduced into the above, a paraffinic non-polar hydrocarbon solvent is preferably used as the solvent. Preferred examples of the solvent include n-hexane, n-octane, and n.
-Nonane, n-dodecane, cyclohexane and cyclooctane.

Since the resulting intermediate polymer is insoluble in these solvents, it is convenient to separate the intermediate polymer from unreacted dichlorosilane monomer. The separated intermediate polymer is then reacted with the above-mentioned halogenated organic reagent, in which case both are dissolved in the same solvent and subjected to the reaction. As the solvent in this case, an aromatic solvent such as benzene, toluene or xylene is preferably used.

When the desired intermediate is obtained by condensing the above-mentioned dichlorosilane monomer using the above-mentioned alkali metal catalyst, the degree of polymerization of the obtained intermediate polymer can be appropriately controlled by adjusting the reaction temperature and the reaction time. However, the reaction temperature at that time is preferably set between 60 and 130 ° C.

One desirable mode of the method for producing the above-mentioned polysilane represented by the general formula (I) used in the present invention described above will be described below.

That is, the method for producing a polysilane compound comprises (i) a step of producing an intermediate polymer, and (ii) a step of introducing substituents A and A'to the terminals of the intermediate polymer.

The above step (i) is performed as follows. That is,
The reaction system of the reaction vessel was completely deprived of oxygen and water and maintained at a predetermined internal pressure controlled by argon, and an oxygen-free paraffinic solvent and an oxygen-free condensation catalyst were added, and then an oxygen-free dichlorosilane monomer was added. And the whole is stirred and heated to a predetermined temperature to condense the monomer. At this time, the condensation temperature of the dichlorosilane monomer is adjusted by controlling the reaction temperature and the reaction time so that an intermediate polymer having a desired polymerization degree is produced.

As shown in the following reaction formula (i), the reaction at this time causes a desalting reaction between the chloro group of the dichlorosilane monomer and the catalyst, and the Si groups repeat condensation to form an intermediate polymer. To do.

The specific reaction procedure is to prepare a condensation catalyst (alkali metal) in a paraffinic solvent and add the dichlorosilane monomer dropwise while stirring under heating. The degree of polymerization is confirmed by sampling the reaction solution.

A simple confirmation of polymerization can be judged by volatilizing the sampling liquid to form a film. When the condensation proceeds and a polymer is formed, it becomes a white solid and precipitates from the reaction system. Here, it is cooled and the solvent containing the monomer is separated from the reaction system by decantation to obtain an intermediate polymer.

Then, the step (b) is performed. That is, the chloro group of the terminal group of the obtained intermediate polymer is desalted and condensed using a halogenated organic agent and a condensation catalyst (alkali metal) to replace the polymer terminal group with a predetermined organic group. The reaction at this time is represented by the following reaction formula.

At this point, specifically, an aromatic solvent is added to and dissolved in the intermediate polymer obtained by the condensation of the dichlorosilane monomer. Next, a condensation catalyst (alkali metal) is added, and the halogenated organic agent is added dropwise at room temperature. At this time, since it competes with the condensation reaction between the polymer terminal groups, the halogenated organic agent is added in an excess amount of 0.01 to 0.1 times with respect to the starting monomer. Heat gradually and stir at 80-100 ° C for 1 hour to carry out the desired reaction.

After the reaction, the mixture is cooled and methanol is added to remove the alkali metal of the catalyst. The polysilane is then extracted with toluene and purified on a silica gel column. Thus, the desired polysilane is obtained.

Specific examples of R ₁ R ₂ SiCl ₂ and R ₃ R ₄ SiCl ₂ Note: Among the following compounds, a-2 to 16,18,20,21,23,24
Is used for R ₁ R ₂ SiCl ₂ , and a−1,2,11,17,19,22,23,25 is
Used for R ₃ R ₄ SiCl ₂ .

(CH ₃ ) ₂ SiCl ₂ a-1 _{((CH 3) 2 CH)} 2 SiCl 2 a-22 _{((CH 3) 3 C)} 2 SiCl Specific examples of ₂ a-25 A-X and _{A'-X (CH 3) 2} CHCH 2 Cl b-1 CH 3 (CH 2) 4 Cl b-2 CH 3 ( CH ₂ ) ₅ Cl b-3 CH ₃ (CH ₂ ) ₁₀ Cl b-4 CH ₃ (CH ₂ ) ₅ Br b-14 CH ₃ (CH ₂ ) ₁₀ Br b-15 Alkali metals are preferred as the catalyst.

Lithium, sodium and potassium are used as the alkali metal. The shape is preferably wire-like or chip-like to increase the surface area.

Examples of preferred polysilanes for use in the present invention Note): Both X and Y in the above structural formulas represent monomer polymerization units.

[Production Example of Polysilane]

Production Example 1 A three-necked flask was prepared in a blow box in which vacuum suction and argon substitution were performed, a reflux condenser, a thermometer, and a dropping funnel were attached to this, and argon gas was passed through a bypass pipe of the dropping funnel.

Into this three-necked flask, 100 g of dehydrated dodecane and 0.3 mol of wire-shaped sodium metal were charged, and stirred with stirring 1
Heated to 00 ° C. Next, 0.1 mol of dichloromethylphenylsilane monomer (manufactured by Chisso Corporation) (a-7) was dissolved in 30 g of dehydrated dodecane, and the prepared solution was slowly added dropwise to the reaction system.

After dropping, a white solid was deposited by polycondensation at 100 ° C. for 1 hour. After that, the mixture was cooled, decanted with dodecane, and further added with 100 g of dehydrated toluene to dissolve the white solid.
Mole was added. Then, a solution prepared by dissolving 0.01 mol of n-hexyl chloride (manufactured by Tokyo Kasei) (b-3) in 10 ml of toluene was slowly added dropwise to the reaction system while stirring, and heated at 100 ° C. for 1 hour. . After cooling, 50 ml of methanol was slowly added dropwise to treat excess metallic sodium. This produced a suspension layer and a toluene layer.

Next, the toluene layer was separated, concentrated under reduced pressure, then developed by silica gel column chromatography and purified to obtain polysilane No. P-1. The yield was 65%.

The weight average molecular weight of this polysilane was 75,000 as measured by THF development by the GPC method (polystyrene was used as a standard).

Production Example 2 A three-necked flask was prepared in a blow box which was vacuum-evacuated and purged with argon. A reflux condenser, a thermometer, and a dropping funnel were attached to the flask, and argon gas was passed through a bypass pipe of the dropping funnel.

100 grams of dehydrated n-hexane and 1
Add 0.3 mol of mm-square metal sodium and stir for 8 hours.
Heated to 0 ° C. Next, 0.1 mol of dichloromethylhexylsilane monomer (manufactured by Chisso Corporation) (a-13) was dehydrated n.
-The solution prepared by dissolving in hexane was slowly added dropwise to the reaction system. After the dropping, white solid was deposited by polycondensation at 80 ° C. for 3 hours. After that, the mixture is cooled, n-hexane is decanted, and dehydrated toluene 100 is added.
The white solid was dissolved by adding gram and 0.01 mol of sodium metal was added. Next, 0.01 mol of n-hexyl chloride (manufactured by Tokyo Kasei) (b-3) was added to 10 ml of toluene.
The solution prepared by dissolving in 1 was slowly added dropwise to the reaction system while stirring, and heated at 80 ° C. for 1 hour. After cooling, 50 ml of methanol was slowly added dropwise to treat excess metallic sodium. This produced a suspension layer and a toluene layer.

Next, the toluene layer was separated, concentrated under reduced pressure, developed with a silica gel column and chromatographed, and purified to obtain polysilane No. P-2. The yield was 58% and the weight average molecular weight was 120,000.

Production Examples 3 to 5 Polysilane No. P-3 was produced in the same manner as Production Example 2, and polysilane Nos. P-4 and P-5 were produced in the same manner as Production Example 1.

Polysilane No. P-1 to P obtained by Production Examples 1 to 5
-5 is summarized in Table 1 below.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples.
The present invention is not limited to these examples.

In addition, regarding the obtained product, whether or not it contains a polysilane block composed of a Si-Si bond having a long-chain structure is determined by FT-
Confirmed by IR and / or UV spectrum. In addition to this, the presence or absence of the bond of the substituent of the polysilane polymer is examined by FT-IR, or / and the proton in the substituent is detected.
It was confirmed by investigating by FT-NMR. Furthermore, the structure of the polymer was confirmed by FT-NMR and FT-IR.

From the results obtained above, the structure of the synthetic product was determined.

The measurement by FT-IR was performed by preparing a KBr pellet of a test sample, setting it in Nicolet FT-IR750 (manufactured by Nicolet Japan Co., Ltd.), and measuring it.

The measurement by FT-NMR was performed by dissolving the test sample in CDCl ₃ and setting it in FT-NMR FX-90Q (manufactured by JEOL Ltd.) for measurement.

In the UV spectrum, when the polysilane has a low molecular weight, the spectrum tends to the short wavelength side, and when it has a high molecular weight, the spectrum shifts to the long wavelength side. (Pure & Applied Chemistry), 54 , No.5, pp.1041-1050
(1982).

Example 1 First, 10 parts by weight (hereinafter, referred to as “parts”) of polysilane No. P-1, produced in Production Example 1, 10 parts of a styrene monomer purified by vacuum distillation, and 30 parts of benzene obtained by distillation purification were prepared. These are charged into a glass polymerization tube and attached to a vacuum line. Freeze the polymerization tube with liquid nitrogen and use a vacuum line for 10 ^-2.
After degassing below the tool, the polymerization tube is returned to room temperature and thawed. This operation is repeated three times or more to remove oxygen from the reaction system.

After thawing, polysilane precipitates, so it is redissolved in an ultrasonic bath.

Next, the polymerization tube is kept at 80 ° C in a constant temperature bath. UV absorption filter (UV-D36A, made by Toshiba) is applied to the mercury lamp, and the wavelength is 360 nm.
The polymerization tube was irradiated with the irradiation light for 30 seconds to start the vinyl monomer polymerization. Further, polymerization was carried out at 80 ° C. for 2 hours while shaking the polymerization tube in a dark place. After cooling at room temperature, the polymerization tube is opened and benzene is added to the polymer to take it out. A benzene solution of the polymer was purified by reprecipitation in methanol to obtain the target polysilane block copolymer No. PB-1.

The weight average molecular weight of this polysilane block copolymer was 67,000 as a result of THF development by the GPC method and measurement (polystyrene as a standard).

The results are shown in Table 2.

The polymerization molar ratio of each monomer of the polysilane block copolymer was determined from the ratio of the number of protons in NMR. The yield was shown as a percentage of the weight of the polysilane block copolymer obtained from the total amount of the polysilane and the vinyl monomer charged.

Further, the sample was dissolved in dichloromethane, and the ultraviolet absorption spectrum was measured by a spectrum photometer (U-3400, Hitachi Ltd.) to obtain the maximum absorption wavelength (λma
x) is shown in Table 2. From the NMR and IR data, it was confirmed that the sample had the structure of polysilane block and polystyrene block. In addition, from the ultraviolet absorption spectrum, the sample exhibited the characteristics of polysilane, and it was confirmed that the polysilane did not lower the molecular weight due to light irradiation and maintained a long-chain structure.

Examples 2 to 5 Polysilane block copolymers Nos. PB-2 to PB- were used in the same manner as in Example 1, except that the vinyl-based monomer styrene of Example 1 was replaced with α-methylstyrene, methyl methacrylate, methyl acrylate, and tert-butyl methacrylate. 5
Was synthesized.

The identification results are shown in Table 2.

From the NMR and IR data, it was confirmed that the sample had a structure of polysilane block and each vinyl polymer block. In addition, from the ultraviolet absorption spectrum, the sample exhibited the characteristics of polysilane, and it was confirmed that the polysilane did not lower the molecular weight due to light irradiation and maintained a long-chain structure.

Example 6 First, 14 parts of polysilane No. P-2 produced in Production Example 2, 6 parts of styrene monomer purified by vacuum distillation, and 30 parts of benzene purified by distillation are prepared. These are charged into a glass polymerization tube, and frozen and degassed in the same manner as in Example 1. After thawing, polysilane precipitates, so it is redissolved in an ultrasonic bath.

Next, the polymerization tube is kept at 80 ° C in a constant temperature bath. An ultraviolet absorption filter UV-35 and UV-D36S was applied to a mercury lamp, and a polymerization tube was irradiated with irradiation light having a wavelength of 350 nm for 30 seconds to initiate vinyl monomer polymerization.

Further, polymerization was carried out at 80 ° C. for 2 hours while shaking the polymerization tube in a dark place. After cooling at room temperature, the polymerization tube is opened and benzene is added to the polymer to take it out. The benzene solution of the polymer was purified by reprecipitation in methanol to obtain the target polysilane block copolymer No. PB-6.

Identification was performed in the same manner as in Example 1, and the results are shown in Table 2.

From the NMR and IR data, it was confirmed that the sample had the structure of polysilane block and polystyrene block.

In addition, from the ultraviolet absorption spectrum, the sample exhibited the characteristics of polysilane, and it was confirmed that the polysilane did not lower the molecular weight by light irradiation and maintained a long-chain structure.

Examples 7 to 10 Polysilane block copolymers No. PB-7 to PB- in the same manner as in Example 6 except that styrene which is the vinyl-based monomer in Example 6 was replaced with α-methylstyrene, methyl methacrylate, methyl acrylate, and tert-butyl methacrylate. Ten
Was synthesized.

The identification results are shown in Table 2.

From the NMR and IR data, it was confirmed that the sample had a structure of polysilane block and each vinyl polymer block.

In addition, from the ultraviolet absorption spectrum, the sample exhibited the characteristics of polysilane, and it was confirmed that the polysilane did not lower the molecular weight by light irradiation and maintained a long-chain structure.

Example 11 First, 8 parts of polysilane No. 3 produced in Production Example 3, 12 parts of ethyl acrylate purified by vacuum distillation, and 30 parts of benzene purified by distillation were prepared. These are charged into a glass polymerization tube and freeze-deaerated as in Example 1.

After thawing, polysilane precipitates, so it is redissolved in an ultrasonic bath.

Next, the polymerization tube is kept at 60 ° C. in a constant temperature bath. UV absorption filter (UV-35 and UV-D36S made by Toshiba) is applied to the mercury lamp to set the wavelength.
The polymerization tube was irradiated with irradiation light of 350 nm for 10 seconds to initiate the polymerization of vinyl monomer.

Further, polymerization was carried out at 60 ° C. for 3 hours while shaking the polymerization tube in the dark. After cooling at room temperature, the polymerization tube is opened and benzene is added to the polymer to take it out. The benzene solution of the polymer was purified by reprecipitation in methanol to obtain the desired polysilane block copolymer No. PB-11.

Identification was performed in the same manner as in Example 1, and the results are shown in Table 2.

From the NMR and IR data, it was confirmed that the sample had a structure of polysilane block and polyethylene acrylate block.

In addition, from the ultraviolet absorption spectrum, the sample exhibited the characteristics of polysilane, and it was confirmed that the polysilane did not lower the molecular weight due to light irradiation and maintained a long-chain structure.

Example 12 Polysilane block copolymer No. PB-12 was synthesized in the same manner as in Example 11, except that the vinyl-based monomer ethyl acrylate was changed to butadiene.

The identification results are shown in Table 2.

From the NMR and IR data, it was confirmed that the sample had the structure of polysilane block and polybutadiene block.

In addition, from the ultraviolet absorption spectrum, the sample exhibited the characteristics of polysilane, and it was confirmed that the polysilane did not lower the molecular weight due to light irradiation and maintained a long-chain structure.

Example 13 First, 10 parts of polysilane No. P-4 produced in Production Example 4, 10 parts of methyl methacrylate purified by vacuum distillation, and 30 parts of benzene purified by distillation are prepared. These are charged into a glass polymerization tube and freeze-deaerated as in Example 1.

After thawing, polysilane precipitates, so it is redissolved in an ultrasonic bath.

Next, the polymerization tube is kept at 60 ° C. in a constant temperature bath. Wavelength of UV absorption filter UV-33 and UV-D33S (manufactured by Toshiba)
The polymerization tube was irradiated with irradiation light of 330 nm for 30 seconds to initiate the polymerization of vinyl monomer.

Further, polymerization was carried out at 80 ° C. for 2 hours while shaking the polymerization tube in a dark place. After cooling at room temperature, the polymerization tube is opened and benzene is added to the polymer to take it out. The benzene solution of the polymer was reprecipitated in methanol and purified to obtain the target polysilane block copolymer No. PB-13.

Identification was performed in the same manner as in Example 1, and the results are shown in Table 2.

From the NMR and IR data, it was confirmed that the sample had the structure of polysilane block and polymethylmethacrylate block.

In addition, from the ultraviolet absorption spectrum, the sample exhibited the characteristics of polysilane, and it was confirmed that the polysilane did not lower the molecular weight by light irradiation and maintained a long-chain structure.

Example 14 Polysilane block copolymer No. PB-14 was synthesized in the same manner as in Example 13 except that the vinyl monomer methyl methacrylate was changed to vinyl acetate.

The identification results are shown in Table 2.

From the NMR and IR data, it was confirmed that the sample had the structure of polysilane block and polyvinyl acetate block.

In addition, from the ultraviolet absorption spectrum, the sample exhibited the characteristics of polysilane, and it was confirmed that the polysilane did not lower the molecular weight by light irradiation and maintained a long-chain structure.

Example 15 First, 10 parts of polysilane No. P-5 produced in Production Example 5, 10 parts of methyl methacrylate purified by distillation under reduced pressure, 30 parts of benzene distilled and purified were prepared, and 10 parts of distilled benzene was used. Prepare a section. Charge these into a glass polymerization tube,
Freeze degassing is performed as in Example 1.

After thawing, polysilane precipitates, so it is redissolved in an ultrasonic bath.

Next, the polymerization tube is kept at 80 ° C in a constant temperature bath. Wavelength of UV absorption filter UV-33 and UV-D33S (manufactured by Toshiba)
The polymerization tube was irradiated with irradiation light of 330 nm for 30 seconds to initiate the polymerization of vinyl monomer.

Further, polymerization was carried out at 80 ° C. for 2 hours while shaking the polymerization tube in a dark place. After cooling at room temperature, the polymerization tube is opened and benzene is added to the polymer to take it out. A benzene solution of the polymer was reprecipitated in methanol and purified to obtain the desired polysilane block copolymer No. PB-15.

Identification was performed in the same manner as in Example 1, and the results are shown in Table 2.

From the NMR and IR data, it was confirmed that the sample had the structure of polysilane block and polymethylmethacrylate block.

In addition, from the ultraviolet absorption spectrum, the sample exhibited the characteristics of polysilane, and it was confirmed that the polysilane did not lower the molecular weight by light irradiation and maintained a long-chain structure.

Example 16 Polysilane block copolymer No. PB-16 was synthesized in the same manner as in Example 15 except that the vinyl monomer, methyl methacrylate, was changed to vinyl acetate.

The identification results are shown in Table 2.

From the NMR and IR data, it was confirmed that the sample had the structure of polysilane block and polyvinyl acetate block.

In addition, from the ultraviolet absorption spectrum, the sample exhibited the characteristics of polysilane, and it was confirmed that the polysilane did not lower the molecular weight by light irradiation and maintained a long-chain structure.

Comparative Example 1 Polysilane No. E was synthesized in the same manner as in Production Example 1 except that dichlorosilane monomer (manufactured by Chisso Corporation) (a-7) was condensed in the same manner as in Production Example 1 and the end groups of the polymer were not treated.
-1 was obtained. The yield was 60% and the weight average molecular weight was 46,000. The identification results are shown in Table 2.

In this polysilane compound, IR absorption attributed to unreacted Si—Cl and a by-product Si—O—R was observed in the terminal group.

Comparative Example 2 A three-necked flask was prepared in a blow box that had been vacuum-evacuated and purged with argon. A reflux condenser, a thermometer, and a dropping funnel were attached to this, and argon gas was passed through a bypass pipe of the dropping funnel.

Into this three-necked flask, 100 g of dehydrated dodecane and 0.3 mol of wire-shaped sodium metal were charged, and stirred with stirring 1
Heated to 00 ° C. Next, a solution prepared by dissolving 0.1 mol of dichlorodimethylsilane monomer (manufactured by Chisso Corporation) in 30 g of dehydrated dodecane was slowly added dropwise to the reaction system. After dropping, by polycondensing at 100 ° C for 1 hour,
A white solid was deposited. After cooling, 50 ml of methanol was slowly added dropwise to treat excess metallic sodium.

Next, the white solid was collected by filtration and repeatedly washed with n-hexane and methanol to obtain a polysilane compound No. E-2.

Since this polysilane is insoluble in organic solvents such as toluene, chloroform, and THF, identification was performed by IR. Second result
Shown in the table.

Comparative Example 3 A three-necked flask was prepared in a blow box that had been vacuum-evacuated and purged with argon. A reflux condenser, a thermometer, and a dropping funnel were attached to the flask, and argon gas was passed through a bypass pipe of the dropping funnel.

Into this three-necked flask, 100 g of dehydrated dodecane and 0.3 mol of wire-shaped sodium metal were charged, and stirred with stirring 1
Heated to 00 ° C.

Next, diphenyldichlorosilane monomer (Chisso Corporation)
0.1 mol) was dissolved in 30 g of dehydrated dodecane and the prepared solution was slowly added dropwise to the reaction system. 100 after dropping
A white solid was deposited by polycondensation at 1 ° C. for 1 hour.

After this, it is cooled to treat excess sodium metal,
50 ml of methanol was slowly added dropwise.

Next, the white solid was collected by filtration and repeatedly washed with n-hexane and methanol to obtain polysilane compound No. E-3.

Since this polysilane is insoluble in organic solvents such as toluene, chloroform, and THF, identification was performed by IR. Second result
Shown in the table.

Use Example 1 An example in which the polysilane block copolymer produced by the production method of the present invention is used as a resist material is shown below.

Phenol volac resin (AZ-B50
J: Shipley Co.) 2μ by spin coating method
It was formed to a thickness of m and heated at 150 ° C. for 30 minutes. Next, the polysilane block copolymer No. PB-1,5 obtained in Example 1 was used.
By weight, 0.5 part by weight of p-hydroquinone was dissolved in toluene and applied by a spin coating method to form a polysilane layer having a thickness of 0.3 μm, followed by baking at 90 ° C. for 30 minutes to prepare a composite resist layer.

500W with a quartz mask of 0.2μm and 0.5μm line width
Ultraviolet light was irradiated for 30 seconds with a xenon-mercury lamp. It was immersed in a mixed solvent of toluene-isopropyl alcohol (weight ratio 1: 5) for 30 seconds, developed, and rinsed with isopropyl alcohol to obtain a positive resist pattern having a line width of 0.2 μm and 0.5 μm. Subsequently, oxygen plasma etching was performed, and the lower organic layer was dry-etched, whereby 0.2 μm line width and 0.5 μm line width resist patterns having an aspest ratio of 2 or more could be formed.

The film forming ability of this polysilane block copolymer and the developability of the resist pattern were evaluated and are shown in Table 3.

In addition, the adhesiveness of the composite resist layer was evaluated.

For the composite resist layer on which the above-mentioned polysilane block copolymer layer was formed, make 11 cutting lines with a cutter for each 1 mm, and similarly make 11 cutting lines with a vertical axis, and make 10
Form 0 base mesh. Cellophane tape (manufactured by Nichiban) was attached to the base and peeled off, and the number of bases that did not peel off was counted and used as the measured value.

Use Examples 2 to 19 The polysilane block copolymers used in Use Example 1 were the polysilane block copolymers Nos. 2 to 16 and the polysilane compounds E-1 to E-3 obtained in Comparative Examples 1 to 3.
A resist pattern was formed and evaluated in exactly the same manner except that the above procedure was repeated. The results are shown in Table 3.

[Summary of Effects of the Invention] The polysilane block copolymer according to the method of the present invention is
It is a polysilane block copolymer which is synthesized by a novel production method of polymerizing a vinyl monomer using polysilane as a photoinitiator and is excellent in solubility, film forming ability and adhesiveness.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiro Kashizaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Masahiro Kanai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (1)

[Claims] 1. A novel method for producing a polysilane block copolymer, which comprises photoinitiating polymerization of a vinyl monomer with polysilane by irradiation with light having a wavelength not less than the absorption maximum wavelength of polysilane.