Method of manufacturing a polyacetylene conjugate polymer

Abstract: Disclosed is a method of manufacturing a polyacetylene type superlong conjugate polymer that is stable in an atmosphere containing oxygen. The polymer is made by chemically adsorbing a chemical adsorption substance containing an acetylene group and a chlorosilyl group to a substrate surface, and polymerizing the acetylene group in a solvent containing a Ziegler-Natta catalyst. In a non-aqueous organic solvent, a chemical adsorption substance containing an acetylene group and a chlorosilyl group is dissolved. For example, a substrate is immersed in ω-nonadecylinoic trichlorosilane, and a monomolecular film is formed on the substrate by chemical adsorption. The substrate is then immersed in an organic solvent containing a Ziegler-Natta catalyst, and the acetylene group of the monomolecular film is polymerized.

Description: FIELD OF THE PRESENT INVENTION The invention relates to a method of manufacturing a polyacetylene conjugate polymer having an ultrahigh molecular weight. Such a polyacetylene conjugate polymer may be useful for electric materials and demonstrates conductive or nonlinear optical effects. BACKGROUND OF THE INVENTION Polymers of acetylene derivatives, which possess a one-dimensional main chain having a π-electronic conjugate system and are characterized by the conductivity and nonlinear optical effects, are widely studied as electronic functional materials. A method of manufacturing polyacetylene, by polymerizing acetylene gas with a Ziegler-Natta catalyst, proposed by Shirakawa et al., is well known (Synthetic Metals, vol. 1, p. 175, 1979/1980, Switzerland). Polyacetylene derivatives used at the present are, however, unstable against heat, pressure or ultraviolet rays, in an atmosphere containing oxygen. Stabilization studies are being conducted, but effective methods for stabilizing polyacetylene derivative polymers have not proved satisfactry. EP-A-385656 and EP-A-339677 each discloses methods for producing an ultra long conjugated polyacetylene polymer by chemical adsorption and the use of metal catalysts. FR-A-2555590 discloses the reaction of acetylene gas with a liquid medium containing a Ziegler-type catalyst. SUMMARY OF THE INVENTION The invention has been made in the light of the problems in the prior art. It is the object of this invention to provide a method of manufacturing a polyacetylene conjugate polymer having an ultrahigh molecular weight that is stable in an atmosphere containing oxygen. The above object has been solved by providing a method of manufacturing a polyacetylene conjugate polymer having an ultrahigh molecular weight, comprising contacting a silane-based surface adsorbent having a trimethylsilyl acetylene group represented by the formula (CH 3 ) 3 Si-C≡C- or a trimethylsilyl diacetylene group represented by the formula (CH 3 ) 3 Si-C≡C-C≡C- and a silanol group an alkoxysilane group or a chlorosilane group with a substrate surface to initiate a condensation reaction, washing and removing with a non-aqueous organic solution, unreacted silane-based surface adsorbent on the substrate surface and reacting with water to form a chemical adsorption film having the trimethylsilyl acetylene group or trimethylsilyl diacetylene group, and contacting the chemical adsorption film with an organic solvent containing a Ziegler-Natta catalyst for polymerizing the trimethylsilyl acetylene group or trimethylsilyl diacetylene group of the chemical adsorption film. Preferably, the chemical adsorption film is a monomolecular film. Preferably, the chemical adsorption film having the trimethylsilyl group and acetylene group or diacetylene group is treated with an alkaline aqueous solution. Preferably, the Ziegler-Natta catalyst is prepared by treating a transition metal compound of group IV or VIII in the periodic table with an organic metal compound of an element of group I or IIIa in the periodic table. According to the embodiments of the present invention, using a straight-chain hydrocarbon derivative possessing a trimethylsilyl group at one end, a chemical adsorption film may be formed at a high density (maximum density filling) on the substrate surface by chemical adsorption. Furthermore, by making the surface of the chemical adsorption film hydrophilic by emitting high energy rays in a gas containing oxygen, a cumulative, monomolecular film may be formed. Therefore, chemically adsorbing a part of the straight-chain hydrocarbon by using a substance containing at least one acetylene group, a chemical adsorption film can be formed from an acetylene derivative that is in the order of scores of angstroms (several nanometers) in thickness. The film can be formed at a high density, and several layers of cumulative films may be obtained easily. When the monomolecular films accumulated by this method are immersed in an organic solvent containing a Ziegler-Natta catalyst, and the acetylene group portions of the monomolecular films are polymerized, a polyacetylene of an ultrahigh molecular weight with a very long conjugate system is formed at a high density. Accordingly, it is resistant to attacks of oxygen, and a stable polyacetylene is formed even in the atmosphere containing oxygen. That is, by polymerizing the molecules of an acetylene derivative by using a Ziegler-Natta catalyst in a state of high density and maintaining a specific orientation, a polymer (superlong conjugate polymer) is produced that is stable against heat, pressure or ultraviolet rays, in an atmosphere containing oxygen in an ultrahigh molecular weight in a straight chain with a continuous conjugate system. According to a preferable embodiment of the invention in which the chemical adsorption film is a monomolecular film or a monomolecular cumulative film, an ultrathin chemical adsorption film at the nanometer level of thickness can be formed uniformly. Moreover, since -Si(CH 3 ) 3 is bonded to the acetylene or diacetylene, by treating with an alkaline aqueous solution to stabilize the molecule end to form the chemical adsorption film, the -Si(CH 3 ) 3 group can be eliminated. As a result, the acetylene group or diacetylene group may be exposed at the outermost surface of the chemical adsorption film. In addition, according to one embodiment of the invention in which the Ziegler-Natta catalyst is prepared by treating a transition metal compound of group IV or VIII in the periodic table with an organic metal compound of an element of group I or IIIa in the periodic table, efficient catalyst activity is achieved. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a conceptual molecular diagram of a substrate having one layer of an acetylene adsorption film. Fig. 2 is a conceptual molecular diagram of a substrate having a polyacetylene adsorption film by polymerizing an acetylene adsorption film. Fig. 3 is a conceptual molecular diagram of a substrate having one layer of a diacetylene adsorption film. Fig. 4 is a conceptual molecular diagram of a substrate having a polyacetylene adsorption film by polymerizing a diacetylene adsorption film. DETAILED DESCRIPTION OF THE INVENTION The invention is described in detail below. In a non-aqueous organic solvent, a chemical adsorbent containing an acetylene group at one molecule end and a trichlorosilyl group at the other molecule end is dissolved. A substrate 1 possessing -OH groups is immersed in the solvent to form a hydrophilic substrate having SiO 2 groups. The SiO 2 groups are formed when the -SiCl groups and the -OH groups on the substrate surface react to induce a dehydrochlorination reaction. Consequently, when unreacted matter is removed by washing with a non-aqueous solution, a monomolecular film 2 expressed in the following formula is formed on the substrate surface (Fig. 1). It was confirmed by FTIR (fourier transform infrared spectroscopy) that the monomolecular film 2 expressed by Formula 1 was formed on the substrate surface. Besides, the adsorption films accumulated in the above method were confirmed to be insoluble in an alcohol solvent. In an organic solvent containing a Ziegler-Natta catalyst, when the substrate forming one layer of a monomolecular film is immersed, a polymerization reaction takes place, and polyacetylene 3, as shown in Fig. 2, is produced. The production of polyacetylene was verified by an FTIR spectrum. Fig. 3 is a diagram showing the method of manufacturing polyacetylene using a compound containing diacetylene group and a trichlorosilyl group at the ends of the compound. In a non-aqueous organic solvent, a compound containing an diacetylene group and a trichlorosilyl group at the ends of the compound is dissolved. A substrate possesing -OH groups is immersed into the solvent to form a hydrophilic substrate having SiO 2 groups. The SiO 2 groups are formed when the -OH groups on the substrate surface react with the -SiCl groups to induce a dehydrochlorination reaction. When unreacted matter is removed by washing with a non-aqueous solution, a monomolecular film 4 as shown in Formula 2, is formed on the substrate surface (Fig. 4). It was confirmed by FTIR that the monomolecular film 4 shown in Formula 2 was formed on the substrate surface. At the same time, the absorption films accumulated in this method were confirmed to be insoluble in an alcohol solvent. In an organic solvent containing a Ziegler-Natta catalyst, when the substrate forming one layer of a monomolecular film is immersed, a polymerization reaction takes place, and polyacetylene 5, as shown in Fig. 4, is produced. The production of polyacetylene was verified by an FTIR spectrum. For stabilizing the molecule ends, a substance having a -SiMe 3 group in the acetylene group is used. Examples of such compounds include the following. (CH 3 ) 3 SiC≡C(CH 2 ) n SiCl 3 (where n represents 14 - 24) (CH 3 ) 3 SiC≡C(CH 2 ) n Si(CH 3 )Cl 2 (where n represents 14 - 24) (CH 3 ) 3 SiC≡C(CH 2 ) n Si(CH 3 ) 2 Cl (where n represents 14 - 24) (CH 3 ) 3 SiC≡C-C≡C(CH 2 ) n SiCl 3 (where n represents 12 - 22) (CH 3 ) 3 SiC≡C-C≡C(CH 2 ) n Si(CH 3 )Cl 2 (where n represents 12 - 22) (CH 3 ) 3 SiC≡C-C≡C(CH 2 ) n Si(CH 3 ) 2 Cl (where n represents 12 - 22) When immersed in a 10 wt.% KOH aqueous solution after adsorption, the -Si(CH 3 ) 3 group is dissociated, and similarly the monomolecular films of Formula 3 and Formula 4 may be formed. The Ziegler-Natta catalyst usable in the invention may be obtained by reaction of a transition metal compound of group IV or VIII in the periodic table with an organic metal compound of an element of group I or IIIa in the periodic table. As such organic metal compounds, for example, an alkyl aluminum compound, a zinc alkyl compound and a lithium alkyl compound may be used. As the transition metal compound of group IV or VIII, alkoxide or halide may be used. Examples include the following. Al(C n H 2n+1 ) 3 /Ti(OC m H 2m+1 ) 4 Al(C n H 2n+1 ) 3 /TiCl 4 Al(C n H 2n+1 ) 3 /TiCl 3 Al(C n H 2n+1 ) 3 /VCl 3 Al(C n H 2n+1 ) 3 /MoCl 5 Zn(C n H 2n+1 ) 2 /Ti(OC m H 2m+1 ) 4 LiC n H 2n+1 /Ti(OC m H 2m+1 ) 4 (where n represents an integer from 1 to 10, and m represents an integer from 2 to 10) The invention is further described below by referring to examples. Reference Example 1 A Si substrate forming an oxide film (SiO 2 ) of 7.62 cm (3 inches) in diameter was immersed in a 10 -2 mol/liter solution (80 wt.% hexadecane, 12 wt.% carbon tetrachloride, and 8 wt.% chloroform) of a reaction chemical adsorption substance, ω-nonadecylinoic trichlorosilane (NCS) as shown in Formula 5, for 1 hour at room temperature in a nitrogen atmosphere. CH≡C(CH 2 ) 17 SiCl 3 The substrate was then washed in chloroform, and the unreacted chemical adsorption substance was removed. The substrate was later washed in purified water, and a monomolecular film was formed on the Si surface. Subsequently, the Si substrate forming the molecular film was immersed and polymerized in a mixed solvent composed of a 5 x 10 -2 mol/liter solution (toluene) of triethyl aluminum, and a 2.5 x 10 -2 mol/liter solution (toluene) of tetrabutyl titanate. After washing in toluene for two hours, a sample was obtained. Reference Example 1 A similar experiment was conducted except that ω-nonadecylinoic trichlorosilane in Reference Example 1 was replaced by the reaction chemical adsorption substance, 1-(trimethylsilyl)- ω-nonadecylinoic trichlorosilane (TMS-NCS), as shown in Formula 6. SiMe 3 -C≡C(CH 2 ) 17 -SiCl 3 Reference Example 2 A similar experiment was conducted by replacing ω-nonadecylinoic trichlorosilane in Reference Example 1 with the reaction chemical adsorption substance shown in Formula 7. CH≡C(CH 2 ) 14 - Si(CH 3 )Cl 2 Reference Example 3 A similar experiment was conducted by replacing ω-nonadecylinoic trichlorosilane in Reference Example 1 with the reaction chemical adsorption substance shown in Formula 8. CH≡C(CH 2 ) 24 -Si(CH 3 ) 2 Cl Reference Example 4 A similar experiment was conducted by replacing ω-nonadecylinoic trichlorosilane in Reference Example 1 with the reaction chemical adsorption substance shown in Formula 9. CH 3 (CH 2 ) 3 C≡C-C≡C(CH 2 ) 6 O(CH 2 ) 3 SiCl 3 Reference Example 5 A similar experiment was conducted by replacing ω-nonadecylinoic trichlorosilane in Reference Example 1 with the reaction chemical adsorption substance shown in Formula 10. HC≡C-C≡C(CH 2 ) 6 O(CH 2 ) 19 SiCl 3 Reference Example 6 A similar experiment was conducted by replacing the mixed catalyst in Reference Example 1 with a mixed catalyst composed of a 5 x 10 -2 mol/liter solution (toluene) of trioctyl aluminum and a 2.5 x 10 -2 mol/liter solution (toluene) of tetrabutyl titanate. Reference Example 7 A similar experiment was conducted by replacing the mixed catalyst in Reference Example 1 with a mixed catalyst composed of a 5 x 10 -2 mol/liter solution (toluene) of triethyl aluminum and a 2.5 x 10 -2 mol/liter solution (toluene) of tetrachlorotitanium. Reference Example 8 A similar experiment was conducted by replacing the mixed catalyst in Reference Example 1 with a mixed catalyst composed of a 5 x 10 -2 mol/liter solution (toluene) of triethyl aluminum and a 2.5 x 10 -2 mol/liter solution (toluene) of tetrachlorovanadium. Reference Example 9 A similar experiment was conducted by replacing the mixed catalyst in Reference Example 1 with a mixed catalyst composed of a 5 x 10 -2 mol/liter solution (toluene) of diethyl zinc and a 2.5 x 10 -2 mol/liter solution (toluene) of tetrabutyl titanate. Reference Example 10 A similar experiment was conducted by replacing the mixed catalyst in Reference Example 1 with a mixed catalyst composed of a 5 x 10 -2 mol/liter solution (toluene) of butyl lithium and a 2.5 x 10 -2 mol/liter solution (toluene) of tetrabutyl titanate. Comparative example 1 A polyacetylene film was obtained by polymerizing acetylene gas using a mixed catalyst composed of a 5 x 10 -2 mol/liter solution (toluene) of triethyl aluminum and a 2.5 x 10 -2 mol/liter solution (toluene) of tetrabutyl titanate. Samples of the Example, References 1 to 10 and Comparison 1 were let stand in a 60 °C atmosphere for 30 days, and the FITRs before and after standing were compared. In the comparative sample, an absorption peak was observed at 3450 cm -1 , and oxidation was progressed, but there was no change in FTIR in the sample of the invention and in the reference samples, and oxidation was not initiated. In the Example, a similar experiment was conducted by replacing the substrate with a glass plate. After forming a monomolecular film of polyacetylene, iodine was doped after four hours in a vapor phase. The conductivity was measured, and the result was 5 x 10 -4 S/cm. In the foregoing embodiments, the method of polymerizing by forming a mono-layer chemical adsorption film is shown, but a polymerization reaction may be conducted after laminating multiple layers of the adsorption film. Formation of the adsorption film and the polymerization reaction may be done alternately. The multilayer molecular film of polyacetylene can be similarly manufactured. As described herein, according to the embodiments of the invention, it is theoretically possible to manufacture a straight-chain polyacetylene with an ultrahigh molecular weight having a conjugate system continuously extending several millimeters or more than several centimeters, which is extremely effective in fabricating devices that make use of nonlinear optical effects. By further optimizing the variety and manufacturing conditions of materials such as an acetylene and diacetylene derivative monomer, it is possible to manufacture a stable straight-chain polyacetylene with an ultrahigh molecular weight having the conjugate system continuously extending scores of centimeters or several meters or even longer. In this method, organic superconductive substances not requiring cooling may be manufactured. By the method of the invention, as explained above, it is possible to manufacture a stable polymer of a polyacetylene that is excellent in conductivity and nonlinear optical effects, efficiently in an atmosphere containing oxygen. Moreover, by polymerizing an acetylene derivative using a Ziegler-Natta catalyst in a high density state and keeping a uniform orientation, a polymer (superlong conjugate polymer) which is stable against heat, pressure or ultraviolet rays may be formed in an atmosphere containing oxygen, in the straight chain of a continuous conjugate system, having an ultrahigh molecular weight. As has been shown, the invention is greatly beneficial to industry.

Claims: A method of manufacturing a polyacetylene conjugate polymer having an ultrahigh molecular weight, comprising contacting a silane-based surface adsorbent having a trimethylsilyl acetylene group represented by the formula (CH 3 ) 3 Si-C≡C- or a trimethylsilyl diacetylene group represented by the formula (CH 3 ) 3 Si-C≡C-C≡C- and a silanol group, an alkoxysilane group or a chlorosilane group with a substrate surface to initiate a condensation reaction, washing and removing with a non-aqueous organic solution, unreacted silane-based surface adsorbent on the substrate surface and reacting with water to form a chemical adsorption film having the trimethylsilyl acetylene group or trimethylsilyl diacetylene group, and contacting the chemical adsorption film with an organic solvent containing a Ziegler-Natta catalyst for polymerizing the trimethylsilyl acetylene group or trimethylsilyl diacetylene group of the chemical adsorption film. The method of claim 1, wherein the chemical adsorption film is a monomolecular film. The method of claim 1, wherein the chemical adsorption film having the trimethylsilyl group and acetylene group or diacetylene group is treated with an alkaline aqueous solution. The method of claim 1, wherein the Ziegler-Natta catalyst is prepared by treating a transition metal compound of group IV or VIII in the periodic table with an organic metal compound of an element of group I or IIIa in the periodic table.

Inventors: OGAWA KAZUFUMI, SOGA MAMORU, OGAWA, KAZUFUMI, SOGA, MAMORU
Applicants: MATSUSHITA ELECTRIC IND CO LTD, MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
Application year: 1993
Main classification: C08F38
IPC codes: C08F38, B05D1, H01L51, C09D4