JP2011197577A - Spiral polyacetylene film, method for forming the same, antireflection film, lens and optical waveguide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spiral polyacetylene film which has distribution in film density and in refractive indexes, and to provide a method for forming the same.SOLUTION: The method for forming the spiral polyacetylene film in which a main chain has spiral structure has a process of obtaining the spiral polyacetylene film having distribution in refractive indexes by blending the spiral polyacetylene in which the main chain has clockwise spiral structure with the spiral polyacetylene in which the main chain has counterclockwise spiral structure and then by subjecting a mixture to film formation. The spiral polyacetylene film which is obtained by the method for forming the spiral polyacetylene film and which has distribution in refractive indexes is also provided.

Description

  The present invention relates to a helical polyacetylene film, a method for producing the same, an antireflection film, a lens, and an optical waveguide.

  An important optical property value of an optical material is a refractive index. If the refractive index distribution can be provided inside the element, it can be used as an optical material such as an antireflection film, a lens, or an optical waveguide. As an example of a method for producing an optical material having a refractive index distribution, there is Patent Document 1. Patent Document 1 discloses a method for producing an optical material having an inclined refractive index distribution by using a polymer obtained by mixing and polymerizing two types of monomers having different refractive indexes.

  However, generally, when a material different from the base material is added to the base material, other optical properties such as absorption characteristics may change. Therefore, there has been a demand for a method of generating a refractive index distribution using a similar material, and further using the same material as the base material.

JP-A-10-123336

As described above, there is a demand for a film that is used as an optical material and has a refractive index distribution and at the same time does not change other optical properties such as absorption characteristics.
The present invention has been made in view of such background art, and provides a spiral polyacetylene film having a distribution in the density of the film and a refractive index distribution, and a method for producing the film.

  The present invention also provides an antireflection film, a lens, and an optical waveguide using the above-described helical polyacetylene film.

  A method for producing a helical polyacetylene film that solves the above problems is a method for producing a helical polyacetylene film having a main chain having a helical structure, wherein the main chain helical structure is a right-handed helical polyacetylene; The method includes a step of obtaining a film of helical polyacetylene having a refractive index distribution by forming a film after mixing with a left-handed helical polyacetylene having a chain helical structure.

In addition, the present invention is a spiral polyacetylene film having a refractive index distribution obtained by the method for manufacturing a spiral polyacetylene film.
Further, the present invention is an antireflection film using the above-described helical polyacetylene film.

The present invention also provides a lens using the above-described spiral polyacetylene film.
The present invention also provides an optical waveguide using the above-described helical polyacetylene film.

According to the present invention, it is possible to provide a spiral polyacetylene film having a distribution in the density of the film and having a refractive index distribution, and a method for manufacturing the same.
In addition, the present invention can provide an antireflection film, a lens, and an optical waveguide using the above-described helical polyacetylene film.

It is a block diagram explaining the manufacturing method of the film | membrane of the helical polyacetylene which has refractive index distribution. It is the schematic which shows the density change and refractive index change accompanying the change of the ratio of right-handed / left-handed winding, when helical polyacetylene accumulates. FIG. 4 is a schematic diagram showing a change in circular dichroism spectrum accompanying a change in the right-handed / left-handed ratio in a spiral polyacetylene film. It is a figure explaining the example of the three-dimensional structure of helical polyacetylene. It is a figure explaining the relationship between the helical structure of a main chain and the helical structure of a side chain in the three-dimensional structure of helical polyacetylene. It is a figure explaining that interaction differs by the case where the winding direction of a helical polyacetylene differs and the same case. It is a figure based on the molecular mechanics calculation for demonstrating that the distance between polymers differs by the case where the winding direction of helical polyacetylene differs and the case where it is the same. It is the schematic which shows the volume change accompanying the change of the ratio of right-handed and left-handed when spiral type polyacetylene accumulates. It is the schematic of the preparation apparatus of the batch type alignment film used for this invention. Experimental results of circular dichroism spectrum when the ratio of the S-form of the R-form and S-form is changed to 0, 50, 100% in the film in which helical polyacetylene containing asymmetric carbon in the side chain is accumulated FIG. (A) Change in diffraction angle when the ratio of the S-form of the R-form and S-form is changed to 0, 50, 100% in the film in which the helical polyacetylene containing asymmetric carbon in the side chain is accumulated, (B) It is a figure which shows the experimental result of the change of a refractive index. It is a figure which shows the example which used the helical polyacetylene film | membrane of Example 1 of this invention as an antireflection film. It is a figure which shows the example which used the helical polyacetylene film | membrane of Example 2 of this invention as a lens which has refractive index distribution. It is a figure which shows the example which used the helical polyacetylene film | membrane of Example 3 of this invention as an optical waveguide.

Hereinafter, embodiments of the present invention will be described in detail.
The method for producing a helical polyacetylene film according to the present invention is a method for producing a helical polyacetylene film having a main chain having a helical structure, wherein the main chain helical structure is a right-handed helical polyacetylene, The method includes a step of obtaining a helical polyacetylene film having a refractive index distribution by forming a film after mixing with left-handed helical polyacetylene having a spiral structure.

  A method for forming a spiral polyacetylene film having a refractive index profile according to the present invention will be described with reference to the block diagram shown in FIG. Here, “a film having a refractive index distribution” means “a film whose refractive index is not spatially uniform”, that is, “a film whose refractive index is spatially changed”. The magnitude of the spatial change of the refractive index is arbitrary. In other words, the case where the refractive index changes suddenly and the case where it gradually changes are also targeted.

First, a mixture A and B of a helical polyacetylene having a right-handed spiral structure of a main chain and a helical polyacetylene having a left-handed spiral structure of a main chain are prepared. The mixture A contains right-handed spiral polyacetylene and left-handed spiral polyacetylene at a ratio of x _RA : x _LA (x _RA + x _LA = 1). Similarly, the mixture B contains x _RB : x _LB (x _RB + x _LB = 1). In order to make the density variable, it is necessary that x _RA ≠ x _RB . Ideally, x _RA = 1, x _LA = 0, x _RB = 0, x _LB = 1, or x _RA = 1, x _LA = 0, x _RB = x _LB = 0.5. Although desirable, for example, even if x _RA = 0.6, x _LA = 0.4, and x _RB = x _LB = 0.5, the area where the density or the refractive index can be changed is small. Included in the range.

  Here, the right-handed and left-handed ratios are the ratios of the respective polymers when the polymer length is constant. When there are a plurality of polymer lengths, the ratio of the integrated value of length × number of polymers is used.

When the mixture A and B of the right-handed helical polyacetylene and the left-handed helical polyacetylene described above are mixed at a ratio of y _A : y _B (y _A + y _B = 1), the ratio of right-handed and left-handed (Z _R , z _L ) is given by (z _R = x _RA y _A + x _RB y _B , z _L = x _LA y _A + x _LB y _B ), respectively.

The density when a spiral polyacetylene film is formed using this mixture varies depending on the ratio as shown in FIG. In general, it is known that as the density changes, the refractive index changes in direct proportion to the change. Therefore, due to the above density change, the refractive index also changes as shown in FIG. As described in the lower part of FIG. 1, by changing the mixture in which y _A and y _B are changed according to the position of the layer, the density of the film can be changed stepwise and the refractive index can be changed.

In general, in a right-handed and left-handed helical polyacetylene mixture, it may be difficult to accurately determine the ratio of one helical polyacetylene (eg, x _RA , x _LA ). In such a case, the present invention can be applied by confirming the degree of difference between right-handed and left-handed by a circular dichroism spectrum. For example, in FIG. 3, the ratio of right-handed and left-handed windings is (a) considerably more, (b) slightly more, (c) equal, (d) slightly less, and (e) much less than left-handed. An example (schematic diagram) of a circular dichroism spectrum is shown. As the ratio of right-handed and left-handed turns changes, the peak size and sign in the vicinity of the wavelength from 300 to 350 nm change, so this peak can be considered as a peak due to the main chain of the polymer. When the right-handed ratio is equal to the left-handed ratio, the value of the spectrum becomes approximately zero, and a peak appears when it deviates from that. For example, when the spectrum of the mixture A is (a) and the spectrum of the mixture B (without right / left-handed direction control) is as shown in (c), the mixing ratios y _A and y _B are changed. Then, by mixing A and B to produce a film, a helical polyacetylene film having a density or refractive index distribution can be produced in the same manner as above.

Although the case where the above mixture is of two types A and B has been described, it is also possible to use three or more types of mixture. For example, when the mixtures A, B, and C are used, at least two of the ratios of right-handed spiral polyacetylene in each mixture: x _RA , x _RB , and x _RC need to be different values. There is.

  In the above description, the method of preparing the mixture A, B,... Elsewhere and mixing them in the next step is described, but the present invention is not limited thereto. For example, by changing at least one of the monomer composition, the type and amount of the catalyst, and the type and amount of the additive for reversing the helix in a common reaction system, Varying the proportion of helical polyacetylene. By forming a film using this, it is also possible to produce a spiral polyacetylene film having a variable density or refractive index.

  Hereinafter, the type, structure, manufacturing method, spiral direction control of the helical polyacetylene used in the present invention, a mechanism in which the density changes by right-handed / left-handed mixing, and a specific method for producing the film will be described.

First, a method of manufacturing one of the right-handed spiral polyacetylene and the left-handed spiral polyacetylene with priority over the other will be described. Here, the following three methods are exemplified.
Production method 1: A method of polymerizing substituted acetylene in a system in which a chiral promoter is added to a transition metal complex catalyst in the polymerization of helical polyacetylene.

Production method 2: A method in which a substituted polyacetylene having a substituent having optical activity in the side chain is polymerized using a transition metal complex catalyst.
Production method 3: A method in which an additive having optical activity is mixed with a substituted polyacetylene after polymerization.

(Manufacturing method 1 of one-side spiral type substituted polyacetylene)
A helical substituted polyacetylene in which the direction of spiral winding is controlled can be obtained by polymerizing substituted acetylene in a system in which a chiral promoter is added to a transition metal complex catalyst. Examples of transition metal complex catalysts include rhodium (norbornadiene) chloride dimer ([Rh (NBD) Cl] ₂ ) and rhodium (cyclooctadiene) chloride dimer ([Rh (COD) Cl] ₂ ). Rhodium compounds such as [Rh (NBD) Cl] ₂ are preferred (Macromol. Chem. Phys., 200, 265 to 282 (1999)). Examples of the cocatalyst include amines, lithium compounds, and phosphorus compounds, and triethylamine is particularly preferably used. In addition to dimers of rhodium complexes, monomers such as Rh [C (C ₆ H ₅ ) = C (C ₆ H ₅ ) ₂ ] (NBD) (C ₆ H ₅ ) ₃ P) are used. It may be used. Examples of the chiral promoter include (S) -phenylethylamine and (R) -phenylethylamine. Examples of the substituted acetylene include phenylacetylene having a hydroxymethyl group in the side chain (Reference: Chemistry Letters, 34, 854 to 855 (2005)).

(Manufacturing method 2 of one-side spiral type substituted polyacetylene)
The helical substituted polyacetylene in which the spiral winding direction is controlled can be obtained by polymerizing substituted polyacetylene having a substituent having optical activity in the side chain with the rhodium complex catalyst.

  Examples of the optically active substituent include branched alkyl groups such as (S) -2-butyl group, biologically derived derivatives such as amino acids and peptides, binaphthyl derivatives and pinanyl derivatives having axial asymmetry (Macromolecules, 33, 3978 to 3982 (2000), Macromolecules, 41, 5997 to 6005 (2008), Macromolecules, 29, 4192 to 4198 (1996)).

(Manufacturing method 3 of single-turn spiral type substituted polyacetylene)
The helical substituted polyacetylene in which the spiral winding direction is controlled can be obtained by mixing an additive having optical activity with the substituted polyacetylene. Here, it is essential for the compound having optical activity to form a bond such as a hydrogen bond with the side chain of the substituted polyacetylene.

  Examples of the optically active additive include (S) -phenylethylamine, (S) -naphthylethylamine, and chiral amino alcohol. Examples of the substituted polyacetylene include poly (ethynylbenzoic acid) having a carboxyl group in a side chain (J. Am. Chem. Soc., 117, 11596 to 11597 (1995)).

  Heretofore, three examples of the types of the helical substituted polyacetylene and the production method capable of preferentially producing one of the right-handed and left-handed helical substituted polyacetylenes over the other have been described. Of course, the present invention may be implemented using helical polyacetylenes using methods other than these three and having different right-handed / left-handed ratios.

  An example of the three-dimensional structure of the helical polyacetylene shown above will be described with reference to FIG. FIG. 4 shows chemical formulas, side views, and top views of the spiral polyacetylene without side chains in FIGS. 4 (a), 4 (b), and 4 (c), respectively. Further, examples of chemical formulas, side views, and top views of the helical polyacetylene with side chain are shown in FIGS. 4D, 4E, and 4F, respectively.

  Next, a mechanism that makes it possible to use a spiral polyacetylene having a difference in the ratio of right-handed and left-handed spiral polyacetylene and to have a density distribution using the difference in the ratio will be described. First, the relationship between the mixing ratio and density of right-handed and left-handed spiral polyacetylene will be described.

  The spiral structure will be described with reference to FIG. FIG. 5 (a) is a structural model of a helical polyacetylene extending in the vertical direction as viewed from the side. The carbon atoms of the main chain are numbered sequentially from the bottom. (...- C0 = C1-C2 = C3-C4 = C5-C6 = C7 -...) Further, C1, C3, C5, C7,... Have side chains SC1, SC3, SC5, SC7, respectively. Suppose that ... As an example of the substituent of the original helical substituted polyacetylene, those containing a benzene ring, oxygen, and an alkyl chain as shown in FIG. 4 (d) are used. In the description of (a), the substituent is replaced with a larger sphere.

  A view of the structural model of FIG. 5A viewed from below is shown in FIG. 5B. The rotation angle around the helical axis from C1 through C2, C3,... To C7 is about 338 degrees according to the quantum chemical calculation result in a system without side chains. For this reason, the side chains SC1 and SC7 approaching in the vertical direction are shifted by about 360-338 = 22 degrees around the spiral axis (in the opposite direction to the main chain). Since this has a repeated structure, the side chains SC1, SC7, SC13,... Form one side chain helix. Similarly, SC3, SC9, SC15,... Forms the second side chain, and SC5, SC11, SC17,. The spirals of these three side chains are schematically shown in FIG.

Naturally, when considering the mirror-symmetrical helical polyacetylene, the winding direction of the main chain is opposite to that of the original helical polyacetylene, and the winding direction of the spiral of the side chain is also opposite.
Considering the interaction between a plurality of helical substituted polyacetylenes, the side-chain interaction is important because the directly adjacent portion is a side chain. In many cases, there is a 1: 1 relationship between the winding direction of the main chain and the winding direction of the side chain, and therefore, the results of studies on the winding direction of the side chain instead of the winding direction of the main chain are shown below.

  In FIG. 6, (a) when the side chain winding direction is different, (b) the side chain winding direction is the same. In the case of FIG. 6 (a), the side chain can be approached at the portion where the side chain approaches, so that the side chain can mesh. The reason is that in the vicinity where the two approach each other, the spirals of both extend in a diagonally upward direction from the back of the paper surface of FIG. 6A toward the front. On the other hand, in the case of FIG. 6B, the meshing between the side chains as in (a) hardly occurs, and cannot approach as much as (a). The reason for this is that in the vicinity where they are close, the left spiral extends diagonally upward from the back of the page, and the right spiral extends diagonally upward from the front of the page to the back. This is because the spiral is extended. Therefore, the distance between the two helical polyacetylenes is small (a) and large (b). When there are multiple helical polyacetylenes, those with different side chain winding directions approach each other, and those with the same winding direction move away, so the density changes due to the volume changing depending on the composition ratio. .

  In order to support the above trend, we performed a verification using molecular mechanics calculation (using universal force field). FIG. 7 shows the result of analyzing the helical polyacetylene having the chemical formula shown in FIG. It can be seen that when the winding direction of FIG. 7 (a) is different, the distance between the spiral polyacetylenes is smaller than when the winding direction of FIG. 7 (b) is the same. It was found from molecular mechanics calculation that the energy was lower. The energy difference was 0.041 eV when converted per set of C = C. That is, it is considered that helical polyacetylene having different winding directions are closer to each other under conditions closer to equilibrium.

FIG. 8 shows an outline of the volume change when such a helical polyacetylene is accumulated. Here, in the white and gray circles, the winding direction of the spiral of the side chain is right-handed and left-handed, respectively. As above-mentioned, right-handed and left-handed cannot approach, and right-handed and left-handed can approach. In addition, according to molecular mechanics calculations, it is considered that the adjoining spiral polyacetylenes with different winding directions have lower energy than when the winding directions are the same, so they will mix rather than phase separate under near-equilibrium conditions. It is done. FIG. 8 shows an example in which the ratios of white circles (right-handed) are (a) 50%, (b) 33%, and (c) 0%. It can be seen that when the ratio of white circles (right-handed) in the whole deviates from 50%, the same winding direction becomes adjacent, and the volume increases (density decreases). In this way, it is possible to change the refractive index by changing the density by changing the ratio of right-handed / left-handed helical polyacetylene.
As described above, it is possible to change the refractive index by changing the density by controlling the ratio of right-handed / left-handed.

Next, a method of actually forming a spiral polyacetylene film having a difference in the ratio of the right-handed and left-handed ones in the spiral polyacetylene will be described.
First, in order to change the density of the film, it is desirable that the film is a film in which some molecules are oriented. The reason is that in the present invention, the density is changed by utilizing the fact that the distance between the polymers changes depending on whether the spiral winding direction is the same or different when the spiral polyacetylene polymers are adjacent to each other. This is because when the spiral polyacetylene is not arranged, the effect becomes very small.

  For this purpose, the method for aligning the helical polyacetylene molecules is not particularly limited. As an example, there is a method in which a spread film of a helical substituted polyacetylene molecule is produced on the surface of water or the like and transferred onto a substrate.

  A solution in which the main chain spiral structure is a right-handed spiral polyacetylene and a left-handed spiral polyacetylene having a main chain spiral structure mixed in a predetermined ratio is spread on a water surface, and is applied to a substrate by Langmuir-Blodgett method. It is preferable to transfer and form a film.

  The mixing ratio of the spiral polyacetylene (R) in which the main chain helical structure is right-handed and the left-handed helical polyacetylene (L) in which the main chain helical structure is left-handed is R: L = 0: 1 (or 1: 0). To 0.5: 0.5 is desirable.

  Further, a plurality of layers of films can be formed while changing the mixing ratio of the spiral polyacetylene having a right-handed helical structure of the main chain and the left-handed helical polyacetylene having a helical structure of the main chain.

  A method for producing the alignment film by transferring the above water surface development film will be further described. This method is an application of a method for producing an amphiphilic polymer laminated film generally called “Langmuir Brogitte (hereinafter referred to as LB) film”.

  First, a water tank 101 as shown in FIG. 9 is prepared and filled with high-purity water such as distilled water. (A) of FIG. 9 is a top view of a water tank, (b) is a side view. The size of the water tank 101 may be determined in consideration of the size of the substrate to be inserted. Technologies common to these LB film fabrication are disclosed in documents such as “Thin Solid Films”, 221 (1992) 276, “Thin Solid Films”, 284 (1996) 152, and the like.

  First, a solution in which helical substituted polyacetylene molecules are dissolved is dropped onto a clean water surface in the water tank 101. As the solvent, any hydrophobic solvent can be used as long as it has a high evaporation rate and dissolves polyacetylene molecules. For example, chloroform is preferable. The amount of chloroform and the concentration of polyacetylene may be determined so that the monomolecular layer spreads on the water surface. In addition, when an amphiphilic solvent such as alcohol is added to the hydrophobic solvent in an amount of 2 to 4% by weight with respect to the hydrophobic solvent, the film spreading speed increases, so that the film formation time can be shortened.

  Next, the movement barrier 103 is moved while looking at the film pressure gauge 102, and adjustment is performed so that a developed film in which single molecules are aligned is formed on the water surface. In FIG. 9, one moving barrier 103 is installed at one end of the water tank 101. However, if two moving barriers are installed on both sides of the water tank, the membrane pressure and directionality of the water surface deployment membrane can be adjusted with higher accuracy. it can.

  The water surface monomolecular development film thus produced is transferred and laminated on the surface of the substrate 104 by moving the substrate 104 up and down. The material of the substrate 104 is not particularly limited, such as glass or a plastic film, as long as the helical substituted polyacetylene molecule is attached. A substrate on which electrodes are formed in advance may be used. Although the water surface development film decreases with the transfer, it is necessary to move the movement barrier 103 in the direction of the arrow 107 so that the value of the pressure gauge 102 is always kept constant so that the orientation of the development film is not disturbed. Of course, the position of the movement barrier 103 may be automatically controlled in conjunction with the value of the pressure gauge 102.

  Since the molecular film layer is stacked on the surface of the substrate 104 as many times as the substrate is moved up and down, if a multilayer film is necessary, the substrate 104 may be submerged or pulled up a plurality of times. If the liquid level development film is insufficient, the operation of moving the temporary substrate 104 up and down is stopped, and the solution in which the helical substituted polyacetylene molecules are dissolved is dropped again on the water surface.

  The initially formed water surface spread film may not be sufficiently oriented, and several layers after the start of transfer may have low orientation. In that case, the water surface spreading film improves the orientation by the flow of water due to the movement of the movement barrier 103 and the substrate 104, and when the water surface spreading film is moved up and down 5 to 10 times, the orientation of the molecules in the water surface spreading film is aligned. The degree of orientation of the film increases and becomes stable. For this reason, when it is necessary to transfer a highly oriented film of one layer or several layers onto a substrate, the transfer laminated film on the substrate is peeled off once after transferring about 10 layers, or a dummy substrate 10 After transferring the layers, the substrate may be replaced with a new one and transferred and laminated again.

  The alignment film creation method described above is an example in which a multilayer film is batch-produced using a water tank having no water flow, but it is also possible to continuously create a film in a water tank having a water flow. In particular, the density or refractive index is continuously changed by forming a film using a means for introducing a helical substituted polyacetylene in which the ratio of right-handed / left-handed is continuously changed in a water tank having a water flow. The film formation of the helical substituted polyacetylene becomes possible. In this case, a highly oriented film is obtained from the first layer. The continuous film forming apparatus is disclosed in JP-A-8-1058, and the apparatus can also be used in the present invention.

In the above, the method for producing the in-plane oriented film using the LB method has been described. In the direction perpendicular to the film, the orientation of each layer may be the same or different.
The helical polyacetylene film of the present invention is a helical polyacetylene film having a refractive index distribution obtained by the above-described method for producing a helical polyacetylene film.

The refractive index distribution of the helical polyacetylene film is preferably 1.52 to 1.54.
Next, the antireflection film of the present invention is an antireflection film using the above-described helical polyacetylene film.

The lens of the present invention is a lens using the above-described spiral polyacetylene film.
The optical waveguide of the present invention is an optical waveguide using the above-described spiral polyacetylene film.

Examples of the present invention will be described below, but these do not limit the present invention.
In Example 1, spiral polyacetylene having an asymmetric carbon in the side chain and having a relationship of optical isomers: poly (propiolic acid-S-2-butyl) (PS2BP, S-form) and poly (propiolic acid- R-2-butyl) (PR2BP, R-form) was synthesized by the above-described production method (2).

The manufacturing method of PS2BP is shown below.
A test tube was charged with 40 mg of rhodium (norbornadiene) chloride dimer and 8.8 ml of methanol, and 1.0 g of propiolic acid-S-2-butyl was injected with a syringe to initiate the polymerization reaction. The reaction was carried out at 40 ° C. for 24 hours. The precipitated polymer was washed with methanol, filtered, and dried under vacuum to obtain the desired product. The weight average molecular weight (Mw) of the polymer evaluated by GPC using a styrene standard was 9.6 × 10 ⁴ and the molecular weight dispersion (Mw / Mn) was 2.6.

Thereafter, a film was formed by the LB method, and a structural analysis experiment (X-ray diffraction experiment) of the film was performed. The evaluation was made on three types of polymer films.
・ Only PS2BP (PS2BP = 100%)
・ Only PR2BP (PS2BP = 0%)
・ P2BP (PS2BP / PR2BP is synthesized without distinction) (PS2BP = 50%)

  Based on the molecular orbital calculation, it can be seen that the S-form (PS2BP) easily forms polyacetylene in which the main chain helix is right-handed and the side chain helix is left-handed. Similarly, it can be seen that the R form (PR2BP) tends to form polyacetylene in which the main chain helix is left-handed and the side chain helix is right-handed. The ratio of PS2BP: 0,100% means that the ratio cannot be measured strictly and is obtained within the range of the above-mentioned manufacturing method. .

  In FIG. 10, the measurement result of the circular dichroism spectrum of the film | membrane by said 3 types of polymer is shown. From this result, PS2BP and PR2BP have large peaks with different signs in the vicinity of the wavelength of 300 to 400 nm, and the peaks do not appear in the synthesized P2BP without distinguishing them, so the spiral with different left-handed / right-handed ratios. It is recognized that type polyacetylene is formed. Ideally, the result of PS2BP and PR2BP is the one with the sign inverted, but this is not the case in FIG. This is probably because the results are not completely symmetrical due to factors such as the amount of chiral monomer, synthesis conditions, and product concentration.

  Next, the result of the X-ray diffraction experiment of the film is shown in FIG. In the figure, the S ratio (%) indicates the ratio of the S form in the mixture of the S form (PS2BP) and the R form (PR2BP). From FIG. 11, the diffraction angle 2θ is large at the center (PS2BP ratio = 50%), which means that the surface separation for generating diffraction is small and the density is large. Conversely, at the end (PS2BP = 0% or 100%), it means that the density is small, and this result supports the result described above. Originally, the end values should be equal, but in this experiment, conditions such as synthesis process or purification process differ slightly between PS2BP only and PR2BP only. As a result, S-body / R It is considered that the body ratio did not become a symmetric value and the diffraction angle was slightly different.

  FIG. 11B shows the measurement results of the refractive index in the above three types of films. The result of having evaluated using two types of incident light (wavelength 500nm, 600nm) is shown. From this figure, the refractive index is a mountain-shaped graph. In general, considering that the refractive index of the material increases when the density of the material is large, it is inconsistent with the theoretical considerations and the result of FIG. It can be confirmed that the experimental results are not.

  Using the PS2BP (S-form) and PR2BP (R-form) described above, as shown in FIG. 12, a film in which the ratio of the S-form and R-form is changed on the glass substrate is produced by the LB method described above. To do. The total film thickness of the helical polyacetylene film is 3 μm, but this film thickness value does not limit the present invention. Film formation is performed by determining the mixing ratio of the S body and the R body so that the density of the film varies from layer to layer as shown in FIG. As a result, a film whose refractive index changes from 1.52 to 1.54 can be formed with incident light having a refractive index of 500 nm. When this film is formed, the reflectance is smaller than when the film is not formed, and it can be confirmed that the antireflection effect can be obtained by applying the helical polyacetylene.

  FIG. 13 shows an example of a lens using helical polyacetylene having a refractive index distribution. The refractive index at the center is the largest at 1.560, the refractive index at the lower end and the upper end is as small as 1.535, and in the middle, by gradually controlling the ratio of right-handed / left-handed as in Example 1, It is designed so that the refractive index decreases toward the end. A representative value of the refractive index of each region is shown on the right side of the figure. The film thickness of the lens is 10 μm, but this value does not limit the present invention. This figure schematically shows how light incident from the left side of the lens travels inside the lens. With this lens, light having a width in the vertical direction can be collected. Since light can be collected using a rectangular parallelepiped optical element instead of a spherical surface, the optical device can be reduced in size and weight.

  FIG. 14 shows an example of an optical waveguide using helical polyacetylene having a refractive index distribution. Similar to Example 2, the refractive index distribution is given in the direction perpendicular to the film. The thickness of the optical waveguide is 10 μm, but this value does not limit the present invention. In this figure, light rays traveling in the waveguide are schematically shown. In this way, light having various components in the direction perpendicular to the film can be propagated through the optical waveguide. Since the helical polyacetylene film having the refractive index distribution can be formed on a soft material, the film thus obtained becomes a flexible film and can be used as a bendable optical waveguide.

  The present invention can provide a spiral polyacetylene film having a distribution in the film density and a refractive index distribution, so that it can be used for an antireflection film, a lens, an optical waveguide, etc. using the spiral polyacetylene film. can do.

DESCRIPTION OF SYMBOLS 101 Water tank 102 Pressure gauge 103 Movement barrier 104 Substrate 105 Deployment film

Claims (8)

  A method for producing a film of a helical polyacetylene having a main chain having a helical structure, wherein the helical structure of the main chain is a right-handed helical polyacetylene and a helical polyacetylene having a main chain of a left-handed spiral structure is mixed. A method for producing a helical polyacetylene film, comprising a step of obtaining a helical polyacetylene film having a refractive index distribution by forming a film.   A solution in which the spiral structure of the main chain is a right-handed spiral polyacetylene and the left-handed spiral polyacetylene of the main chain is developed on a water surface and transferred to a substrate by the Langmuir-Blodgett method. The method for producing a helical polyacetylene film according to claim 1, wherein the film is formed.   3. The spiral type according to claim 1, wherein a film of a plurality of layers is formed while changing a mixing ratio of the spiral polyacetylene having a right-handed helical structure of the main chain and a left-handed helical polyacetylene having a helical structure of the main chain. A method for producing a polyacetylene film.   4. The method for producing a helical polyacetylene film according to claim 1, wherein the refractive index distribution of the helical polyacetylene film is in the range of 1.52 to 1.54. .   A helical polyacetylene film having a refractive index distribution obtained by the method for producing a helical polyacetylene film according to any one of claims 1 to 4.   An antireflection film using the helical polyacetylene film according to claim 5.   A lens using the helical polyacetylene film according to claim 5.   An optical waveguide using the spiral polyacetylene film according to claim 5.

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