Film that exhibits metallic luster and paint that produces said film

Abstract

To provide a film that exhibits a strong metallic luster, and a coating material that produces the film.SOLUTION: The metallic luster exhibiting film comprises a thiophene copolymer in which a thiophene and a thiophene derivative or a plurality of kinds of thiophene derivative are copolymerized. The plurality of kinds of thiophene derivative are 3-methoxythiophene and 3,4-dimethoxythiophene.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a film that exhibits metallic luster and a coating material for producing the film. [Background technology]

[0002] Metals are generally hard and are used in parts that require mechanical strength, such as in home appliances and automobiles, and also have a metallic luster that gives them a good texture, making them used in all kinds of items in daily life, such as furniture, miscellaneous goods, etc. However, metals are not only expensive as materials themselves, but are also not easy to process, so items made of metal tend to be expensive.

[0003] Methods for inexpensively producing articles with metallic luster include, for example, metal plating, which coats the surface of an article made of a polymer compound or glass with a thin metal film, and surface treatment techniques, such as applying paint containing fine particles or flakes of metal to the surface of the article.

[0004] However, metal plating is limited to the materials that can be surface-treated, and paints containing added metals have issues such as the difference in specific gravity between the polymer binder and the metal in the paint causing metal particles to settle, resulting in spots when the paint is formed.

[0005] Therefore, efforts have been made to solve the above problems by using non-metallic substances other than metals to produce metallic luster. Patent Document 1, for example, describes a technique related to non-metallic substances that exhibit metallic luster. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6308624 (pages 8 to 10, Figure 11) Summary of the Invention [Problem to be solved by the invention]

[0007] The technology described in Patent Document 1 involves, for example, synthesizing a polymer of 3-methoxythiophene using an oxidizing agent, dissolving the polymer in a solvent to form a coating material, and applying the coating material onto a glass substrate, thereby obtaining a film that is inexpensive, versatile, and has a metallic luster. Such metallic luster films are required to have a stronger luster (higher reflectance), and the inventors' research has led to the discovery of a film that exhibits a strong metallic luster without using metal.

[0008] The present invention has been made in light of these problems, and has an object to provide a film that exhibits a strong metallic luster and a paint for producing such a film. [Means for solving the problem]

[0009] A film exhibiting metallic luster according to one aspect of the present invention for solving the above problems is as follows: The composition is characterized by including a thiophene copolymer in which thiophene and a thiophene derivative or a plurality of types of thiophene derivatives are copolymerized. According to this feature, a film exhibiting a strong metallic luster can be obtained. In addition, by combining thiophene and a thiophene derivative or a combination of multiple types of thiophene derivatives, the reflectance and color tone of the resulting film can be easily adjusted.

[0010] The thiophene copolymer is characterized in that it is a random copolymer. This feature makes it possible to easily dissolve the thiophene copolymer in a solvent.

[0011] The plurality of types of thiophene derivatives are characterized in that they have the same substituents. According to this feature, the structure of the thiophene copolymer is planarized, so that a film exhibiting a strong metallic luster can be obtained.

[0012] The multiple thiophene derivatives may be 3-methoxythiophene and 3,4-dimethoxythiophene. This feature makes it possible to achieve high reflectance.

[0013] A coating material for forming a film exhibiting metallic luster according to another aspect of the present invention comprises: The composition is characterized by including the thiophene copolymer and a solvent. According to this feature, the occurrence of spots in the formed film can be suppressed. Effect of the Invention

[0014] As described above, the present invention provides a film exhibiting a strong metallic luster and a coating material for producing the film. In addition, by combining thiophene and a thiophene derivative or a combination of multiple types of thiophene derivatives, the reflectance and color tone of the produced film can be adjusted, and the produced film has high extensibility. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a schematic cross-sectional view of an object on which a metallic luster film containing a thiophene copolymer according to an embodiment is formed. [Diagram 2] FIG. 1 is a schematic diagram showing a polymerization apparatus used in Example 1. [Diagram 3] FIG. 2 is an image diagram of the layer structure of the powder obtained in Example 1. [Figure 4] FIG. 2 is a photograph of the membrane obtained in Example 1. [Diagram 5] FIG. 2 is a diagram showing the reflection spectrum of the film obtained in Example 1. [Figure 6] FIG. 13 is a diagram showing the reflectance spectrum of the film obtained in Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described in detail with reference to Figures 1 to 6. However, the present invention can be embodied in many different forms and is not limited to the following embodiments and examples.

[0017] FIG. 1 is a schematic diagram of a cross section of an article on which a metallic luster film containing a thiophene copolymer according to this embodiment is formed.

[0018] The articles on which the metallic gloss film of this embodiment is formed are not particularly limited as long as the metallic gloss film can be formed on the surface thereof, and include not only electronic products such as home appliances and automobiles, mechanical products and their parts, but also miscellaneous goods used in daily life such as furniture and toys, clothing, paper products, packaging, and all sorts of other items. However, it is preferable that the material be made of a polymer compound or glass, from the viewpoints of ease of film formation and low manufacturing costs.

[0019] In addition, in this embodiment, the thickness of the metallic gloss film is not limited as long as it can exhibit metallic gloss, but a thickness of 0.1 μm or more will result in a metallic gloss film, and a thickness of 1 μm or more will result in a more sufficient metallic gloss film.

[0020] Moreover, the metallic luster film according to this embodiment contains a thiophene copolymer having a distribution peak of the weight-average molecular weight in the range of 100 or more and 100,000 or less.

[0021] In this embodiment, the "thiophene copolymer" refers to a copolymer in which a total of two or more thiophenes and thiophene derivatives are bonded to each other and copolymerized, or a copolymer in which two or more kinds of thiophene derivatives are bonded to each other and copolymerized (for example, a compound represented by the following general formula). In this embodiment, the thiophene copolymer is a so-called oligomer, which is a random copolymer in which the combination of thiophene derivatives, i.e., monomers, is randomly arranged.

[0022] [ka]

[0023] In the above formula, R is a substituent, and is not limited as long as it can give metallic luster to the film, but it is preferably any of an alkyl group, an alkoxy group, an amino group, a hydroxy group, a hydroxyalkyl group, an aryl group, a cyano group, or a halogen, and in order to obtain metallic luster more reliably, it is preferably an alkyl group, an alkoxy group, or a halogen. In addition, R may be one or two in one thiophene ring. In addition, in the thiophene copolymer according to this embodiment, R in the above formula of each thiophene derivative may be the same or different.

[0024] In addition, "thiophene" is a heterocyclic compound containing sulfur, and "thiophene derivative", as is clear from the above description, is a heterocyclic compound containing sulfur and is a compound represented by the following general formula, in which R is defined as above.

[0025] [ka]

[0026] In addition, when R in the above formula is an alkoxy group, the carbon number is preferably 1 or 2. Specific examples include 3-methoxythiophene, 3,4-dimethoxythiophene, 3-ethoxythiophene, 3,4-diethoxythiophene, and 3,4-ethylenedioxythiophene. By making the carbon number 1 or 2, a layered orientation structure can be effectively expressed.

[0027] In addition, when R in the above formula is an alkyl group, the carbon number is preferably 1 or 2. Specific examples include 3-methylthiophene, 3,4-dimethylthiophene, 3-ethylthiophene, and 3,4-diethylthiophene. By making the carbon number 1 or 2, a layered orientation structure can be effectively expressed.

[0028] Furthermore, when R in the above formula is an amino group, examples include 3-aminothiophene, 3,4-diaminothiophene, 3-methylaminothiophene, 3-dimethylaminothiophene, etc. In this case, when the amino group contains carbon, the number of carbon atoms is preferably 1 or 2.

[0029] In the present embodiment, the molecular weight of the "thiophene copolymer" is not limited as long as it can have a metallic luster and can be formed into a film, but it is preferable that the thiophene copolymer is a so-called oligomer.

[0030] In the present embodiment, the thiophene copolymer is not limited as long as it can be made into a metallic gloss film, but is preferably polymerized by a chemical polymerization method. Here, the "chemical polymerization method" refers to polymerization carried out in at least one of a liquid phase and a solid phase using an oxidizing agent.

[0031] In this embodiment, the reason why the thiophene copolymer obtained by chemical polymerization exhibits metallic luster is, although it is only speculation, believed to be because the molecules constituting the thiophene copolymer are regularly oriented and reflect a specific wavelength. This is also supported by the fact that the prepared film shows a sharp peak in X-ray diffraction. This detail means that in the X-ray diffraction measurement of the thiophene copolymer, there is no halo pattern due to the amorphous phase, and the peak believed to be due to the regular structure of the thiophene copolymer can be clearly observed within a predetermined diffraction angle (2θ) range.

[0032] The metallic luster film of this embodiment hardly deteriorates even when left in air for a long period of time because the thiophene copolymer is very stable in air, and can maintain metallic luster for a long period of time.

[0033] Here, the method for producing a metallic luster film in this embodiment (hereinafter simply referred to as "this method") will be described.

[0034] This method includes a step of (1) polymerizing thiophene and a thiophene derivative or a plurality of kinds of thiophene derivatives using an oxidizing agent to obtain a solution containing a thiophene copolymer, and (2) applying the solution containing the thiophene copolymer to an article and drying it. That is, in this embodiment, chemical polymerization is performed to produce a thiophene copolymer.

[0035] First, in this method, (1) thiophene and a thiophene derivative or a plurality of kinds of thiophene derivatives are copolymerized using an oxidizing agent to prepare a solution containing this thiophene copolymer. The "thiophene derivative" used here and the resulting "thiophene copolymer" are as described above. As described above, the thiophene copolymer is preferably in the range of a so-called oligomer.

[0036] In this step, the oxidizing agent is not limited as long as it can produce a thiophene copolymer, and various oxidizing agents can be used, such as ferric salts, cupric salts, cerium salts, dichromates, permanganates, ammonium persulfate, boron trifluoride, bromates, hydrogen peroxide, chlorine, bromine, and iodine, and among these, ferric salts are preferred. It may also be a hydrate. In this case, the counter ions can also be appropriately adjusted and are not limited, and examples thereof include chloride ions, citrate ions, oxalate ions, paratoluenesulfonate ions, perchlorate ions, hexafluorophosphate ions, and tetrafluoroborate ions, and among these, the use of at least one of perchlorate ions, hexafluorophosphate ions, and tetrafluoroborate ions is preferred because it can obtain a metallic luster close to gold. The reason why a metallic luster close to gold can be obtained is, although it is only speculation, thought to be that perchlorate ions, hexafluorophosphate ions, and tetrafluoroborate ions are incorporated into the thiophene copolymer as dopants during polymerization, and bond with the cationic sites generated in the thiophene copolymer to stabilize it, contributing to the formation of an ordered structure. In fact, analysis of the metallic luster film has confirmed that these exist stably.

[0037] In addition, in this process, it is preferable to use a solvent and carry out copolymerization in this solvent. The solvent to be used is not limited as long as it can sufficiently dissolve the above-mentioned oxidizing agent and thiophene and thiophene derivative or multiple types of thiophene derivatives and efficiently copolymerize them, but it is preferable to use an organic solvent that has high polarity and a certain degree of volatility, for example, acetonitrile, nitromethane, γ-butyrolactone, propylene carbonate, nitromethane, 1-methyl-2-pyrrolidinone, dimethylsulfoxide, 2-butanone, tetrahydrofuran, acetone, methanol, anisole, chloroform, ethyl acetate, hexane, trichloroethylene, cyclohexanone, dichloromethane, chloroform, dimethylformamide, ethanol, butanol, pyridine, dioxane, and mixtures thereof, etc., but acetonitrile, nitromethane, γ-butyrolactone, and propylene carbonate are preferable because they dissolve thiophene copolymers and tend to form a film with better metallic luster.

[0038] In this step, the amounts of thiophene and the thiophene derivative or the multiple types of thiophene derivatives, and the oxidizing agent used relative to the solvent can be appropriately adjusted and are not limited. When the weight of the solvent is taken as 1, the total weight of the thiophene and the thiophene derivative or the multiple types of thiophene derivatives is preferably 0.00007 or more and 7 or less, more preferably 0.0007 or more and 0.7 or less, and in the case of iron(III) chloride anhydride, the total weight is preferably 0.0006 or more and 6 or less, more preferably 0.006 or more and 0.6 or less.

[0039] In addition, in this step, the ratio of thiophene or thiophene derivatives to the oxidizing agent is preferably 0.1 to 1000, and more preferably 1 to 100, when the total weight of the thiophene derivatives is taken as 1.

[0040] In addition, in this process, the molar ratio of the thiophene and the thiophene derivative or the multiple types of thiophene derivatives used can be appropriately adjusted and is not limited, but for example, when two types of thiophene derivatives are used, it is preferable that the thiophene derivative with a small molecular weight and the thiophene derivative with a large molecular weight are copolymerized at a molar ratio of 5:1 to 20:1, more preferably at a molar ratio of 9:1. In this range, it is easy to dissolve in water and it is easy to produce a water-soluble paint. In addition, when producing an oil-soluble paint, it is preferable that the thiophene derivative with a small molecular weight and the thiophene derivative with a large molecular weight are copolymerized at a molar ratio of 20:1 to 1:20, more preferably at a molar ratio of 1:1.

[0041] In this step, the multiple types of thiophene derivatives and the oxidizing agent may be added to the solvent at once, or two types of solutions, that is, a solution in which the multiple types of thiophene derivatives are added to the solvent and a solution in which the oxidizing agent is added to the solvent, may be separately prepared, and these solutions may be added to each other to carry out the polymerization reaction.

[0042] The solution containing the thiophene copolymer obtained by this process may be stored as it is, but the solvent in this solution may be removed, washed with a solvent, and then dried to obtain a thiophene copolymer powder, and then a solvent may be added again to prepare a solution containing the thiophene copolymer when forming a film. In this case, the solvent used is the same as the solvent exemplified above, and may be the same as or different from the solvent used in the polymerization. In this way, it is preferable to be able to remove the monomer and oxidizing agent that were added in excess during the polymerization reaction and remain. However, when an oxidizing agent containing the above-mentioned perchlorate ion, hexafluorophosphate ion, or tetrafluoroborate ion is used as the oxidizing agent, they remain because they are stably bonded to the copolymer, and the state of metallic luster can be stably maintained.

[0043] The method also includes the step of (2) applying a solution containing a thiophene copolymer to an article and drying the solution. In this embodiment, the article on which the film is formed is any of the above-mentioned examples.

[0044] In this step, the method for applying the solution containing the thiophene copolymer to the article is not limited as long as it is possible to apply the solution. For example, a spin coating method, a bar coating method, a dip coating method, a drop casting method, etc. can be used. In order to form a solution thick enough to have a metallic luster, the drop casting method or the dip coating method is preferable.

[0045] In addition, in this method, depending on the solvent used, the metallic luster may be more pronounced by polishing the film after drying in the above process. By polishing the film, the degree of orientation of the copolymer can be increased, and a better metallic luster can be obtained. For example, when nitromethane is used as the solvent, a film with metallic luster can be obtained without polishing, but when acetonitrile is used, it is highly desirable to polish the film. The method for polishing the film is not particularly limited, but it is preferable to use, for example, a cloth or paper rag.

[0046] As described above, the present invention can provide a film that exhibits strong metallic luster and a paint for producing the film. In addition, by combining thiophene and a thiophene derivative that constitute the thiophene copolymer or a combination of multiple types of thiophene derivatives, it is possible to adjust the reflectance and color tone of the metallic luster film that is the produced film, and the produced film has high extensibility.

[0047] In addition, the metallic luster film according to the present invention is electrically conductive, and by forming the film according to this embodiment on an insulating article, there is also the advantage that electrical conductivity can be ensured. EXAMPLES

[0048] Here, the film of Example 1 according to the above embodiment was actually produced, and its effects were confirmed. A specific description will be given below.

[0049] (1) Synthesis of 3-methoxythiophene and 3,4-dimethoxythiophene copolymers First, 20 ml of an acetonitrile solution (concentration 0.2 M) of anhydrous iron (III) chloride was prepared as an oxidizing agent, and magnetic stirring was performed.

[0050] Next, 3-methoxythiophene as a thiophene derivative with a small molecular weight and 3,4-dimethoxythiophene as a thiophene derivative with a large molecular weight were weighed out to a molar ratio of 9:1, and 20 ml of acetonitrile solution (concentration 0.1 M) was prepared by adding these, and placed in a glass flask, and N2 was bubbled for about 30 minutes while performing magnetic stirring. The schematic diagram of the apparatus used in this case is shown in Figure 2.

[0051] The acetonitrile solution of the iron (III) chloride anhydride was added to the acetonitrile solution of the 3-methoxythiophene and 3,4-dimethoxythiophene, and the mixture was stirred for 2 hours to allow copolymerization to proceed.

[0052] The solution was then distilled off under reduced pressure using an evaporator, and a small amount of ethanol was added thereto.

[0053] The solution and precipitate in the flask were then aspirated and filtered using a membrane filter (pore size 0.1 μm). At that time, the residue on the filter was thoroughly washed with ethanol to remove the oxidizing agent.

[0054] The residue was then dried under vacuum at 50°C to obtain a powder of 3-methoxythiophene, 3,4-dimethoxythiophene copolymer. 3-Methoxythiophene, 3,4-dimethoxythiophene copolymer is a compound represented by the following general formula. Note that the dopant contained in the copolymer is omitted. The powder was black, and a metallic luster like gold or copper was occasionally observed.

[0055] [ka]

[0056] Also, an image of the structure of the thiophene copolymer is shown in FIG. 3. As shown in this figure, it is presumed that the structure of the thiophene copolymer is planarized due to the interaction between S in the five-membered ring structure and the substituent (specifically, O in the methoxy group), and this is one of the causes of the strong metallic luster. In particular, in this embodiment, since the substituents of the two types of thiophene derivatives constituting the 3-methoxythiophene and 3,4-dimethoxythiophene copolymers are the same methoxy group, it is presumed that the structure of the thiophene copolymer is more easily planarized. The substituents of the multiple types of thiophene derivatives constituting the thiophene copolymer may be different. For example, the combination of a methoxy group and a butoxy group increases the electron density of both substituents. Donation The thiophene copolymer is preferred because it has a similar molecular structure and is easy to planarize. In addition, the planarized thiophene copolymer is presumed to be stacked in layers in a regular arrangement, which is also considered to be one of the causes of the metallic luster.

[0057] (Production of metallic gloss films) The 3-methoxythiophene, 3,4-dimethoxythiophene copolymer powder obtained by the above procedure was dissolved in distilled water to prepare two types of water-soluble paints with concentrations of 0.2 wt% and 0.3 wt%. The paints were deep blue in color.

[0058] The paint was then applied onto a glass substrate using a dropper, with the paint being applied thick enough that the opposite side of the substrate was not visible through the paint.

[0059] Next, the substrate coated with the paint was allowed to dry naturally. The surface changed from the deep blue color of the paint to a copper color with a metallic luster. A photograph of this metallic luster film is shown in Figure 4, and its reflection spectrum is shown in Figure 5.

[0060] As shown in Figure 5, the reflectance spectra of four types of films were measured: (1) a metallic luster film prepared from 3-methoxythiophene polymer (polymer A) at a concentration of 0.3 wt%, (2) a metallic luster film prepared from a mixture of 3-methoxythiophene polymer (polymer A) and 3,4-dimethoxythiophene polymer (polymer B) at a concentration of 0.3 wt%, (3) a metallic luster film prepared from 3-methoxythiophene, 3,4-dimethoxythiophene copolymer (copolymer A) at a concentration of 0.2 wt%, and (4) a metallic luster film prepared from 3-methoxythiophene, 3,4-dimethoxythiophene copolymer (copolymer B) at a concentration of 0.3 wt%.The results showed that a strong metallic luster was observed at around 700 nm, with reflectances of 33% and 35%. In addition, the reflectance of the metallic luster films (3) and (4) prepared from 3-methoxythiophene and 3,4-dimethoxythiophene copolymers was approximately 5% higher than that of the metallic luster film (1) prepared from a polymer obtained by polymerizing one type of 3-methoxythiophene.The reflectance was also significantly higher than that of the metallic luster film (2) prepared from a mixture of 3-methoxythiophene and 3,4-dimethoxythiophene polymers, indicating that a strong metallic luster can be obtained by using a 3-methoxythiophene and 3,4-dimethoxythiophene copolymer.

[0061] As shown in FIG. 5, the reflection spectra of the metallic luster films (3) and (4) prepared from 3-methoxythiophene and 3,4-dimethoxythiophene copolymers have a peak value near 700 nm, which indicates a copper color. However, the color tone can be adjusted appropriately by changing the type and molar ratio of the monomers constituting the thiophene copolymer.

[0062] In addition, since the thiophene copolymer is a random copolymer, the monomer arrangement is different in copolymer A forming the metallic luster film (3) and copolymer B forming the metallic luster film (4). In addition, since the thiophene copolymer is a random copolymer, it is more soluble in a solvent than when it is formed from a single monomer such as polymer A forming the metallic luster film (1), and the occurrence of spots in the metallic luster film formed on the glass substrate can be suppressed. EXAMPLES

[0063] Next, a film according to the embodiment 2 was produced and its effect was confirmed. Note that a description of the same configuration as that of the embodiment 1 will be omitted.

[0064] (1) Synthesis of 3-methoxythiophene and 3,4-dimethoxythiophene copolymers First, 10 ml of an acetonitrile solution (concentration 0.2 M) of iron (III) perchlorate n-hydrate was prepared as an oxidizing agent, and magnetic stirring was performed.

[0065] Next, 3-methoxythiophene as a thiophene derivative with a low molecular weight and 3,4-dimethoxythiophene as a thiophene derivative with a high molecular weight were weighed out in two amounts, at a molar ratio of 1:1 and 9:1, respectively, and 10 ml of acetonitrile solution (concentration 0.1 M) was prepared by adding these individually to a glass flask, and N2 bubbling was performed for approximately 30 minutes while performing magnetic stirring.

[0066] The acetonitrile solution of the iron(III) chloride anhydride was added to the acetonitrile solution of the two types of 3-methoxythiophene and 3,4-dimethoxythiophene, and the mixture was stirred for 1 hour to allow copolymerization to proceed.

[0067] The solution and precipitate in the flask were then aspirated and filtered using a membrane filter (pore size 0.1 μm). At that time, the residue on the filter was thoroughly washed with methanol to remove the oxidizing agent.

[0068] The residue was then dried under vacuum at 50°C to obtain two types of 3-methoxythiophene / 3,4-dimethoxythiophene copolymer powders.

[0069] (Production of metallic gloss films) The two types of 3-methoxythiophene and 3,4-dimethoxythiophene copolymer powders obtained by the above procedure were dissolved in nitromethane solution to prepare two oil-soluble paints with a concentration of 1 wt%. The paints were deep blue in color.

[0070] Next, the above paint was applied onto a glass substrate using a dropper. In this case, the paint was applied thickly so that the opposite side of the substrate was not visible through the paint.

[0071] Next, the substrate coated with the paint was allowed to dry naturally. The surface changed from the deep blue color of the paint to a gold color with a metallic luster. The reflectance spectrum of this metallic luster film is shown in Figure 6.

[0072] As shown in Figure 6, the reflectance spectra of three types of films, (1) a metallic film prepared from 3-methoxythiophene polymer (polymer C) at a concentration of 1 wt%, (2) a metallic film prepared from 3-methoxythiophene and 3,4-dimethoxythiophene copolymer (molar ratio 1:1, copolymer C) at a concentration of 1 wt%, and (3) a metallic film prepared from 3-methoxythiophene and 3,4-dimethoxythiophene copolymer (molar ratio 9:1, copolymer D) at a concentration of 1 wt%, were measured, and a strong metallic luster was observed with reflectances of 20% and 21% at around 600 nm. In addition, compared with the metallic film (1) prepared from a polymer polymerized with one type of 3-methoxythiophene, the reflectances of (2) and (3) prepared from 3-methoxythiophene and 3,4-dimethoxythiophene copolymers were about 5% higher. In addition, the metallic luster film (2) prepared from a 3-methoxythiophene polymer in a molar ratio of 1:1 had a higher reflectance than the metallic luster film (3) prepared from a 3,4-dimethoxythiophene polymer in a molar ratio of 9:1. This indicates that in the case of oil-soluble paints, a strong metallic luster can be obtained by preparing a 1:1 molar ratio of 3-methoxythiophene as a thiophene derivative with a low molecular weight and 3,4-dimethoxythiophene as a thiophene derivative with a high molecular weight.

[0073] As shown in FIG. 6, the reflection spectra of the metallic luster films (2) and (3) prepared from 3-methoxythiophene and 3,4-dimethoxythiophene copolymers have a peak value near 600 nm, indicating a golden color, but the color tone can be adjusted appropriately by changing the type and molar ratio of the monomers constituting the thiophene copolymer.

[0074] As described above, a film exhibiting a strong metallic luster and a paint for producing the film were able to be produced by Examples 1 and 2. In addition, by combining thiophene and a thiophene derivative constituting the thiophene copolymer or a combination of multiple types of thiophene derivatives, it is possible to adjust the reflectance and color tone of the metallic luster film produced, and the extensibility of the produced film is high.

[0075] As described above, these embodiments and examples make it possible to provide a film that exhibits a strong metallic luster and a paint that produces such a film. [Industrial Applicability]

[0076] The present invention has industrial applicability as a copolymer that exhibits strong metallic luster. The present invention can be used as a substitute for metal films, and has a wide range of applications, such as inks for writing instruments, oil-based paints, water-based paints, and cosmetics that have metallic luster.

Claims

1. The thiophene copolymer includes thiophene and a thiophene derivative or a thiophene copolymer including a plurality of thiophene derivatives. The thiophene derivative has the same alkoxy group as the substituent, The thiophene copolymer is formed by chemical polymerization, has a layered orientation structure in which the molecules of the thiophene and the thiophene derivative or the multiple types of thiophene derivatives are regularly oriented, and is a film that exhibits a metallic luster, characterized in that no halo pattern is present in X-ray diffraction measurement.

2. 2. The film exhibiting metallic luster according to claim 1, wherein the thiophene copolymer is a random copolymer.

3. 3. The film exhibiting metallic luster according to claim 1, wherein the thiophene copolymer contains a dopant.

4. 4. The film exhibiting metallic luster according to claim 1, wherein the thiophene derivative has a substituent which is an alkoxy group having 1 or 2 carbon atoms.

5. A coating material for forming a film exhibiting metallic luster, comprising the thiophene copolymer according to claim 1 and a solvent.

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