JP2005307011A - pi-CONJUGATED MACROMOLECULAR COMPOSITE PARTICULATE AND PRODUCTION METHOD THEREFOR - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite particulate between an electroconductive polymer and a non-conductive inorganic particulate, which has a high whiteness and can be easily produced without leaving a polymerizing and oxidizing agent in a system. <P>SOLUTION: In the subject π-conjugated macromolecular composite particulate, the surface of the inorganic particulate (I) is coated with a composite (II) of the polymer (b) having a conjugated π electron and an inorganic oxide (c). The π-conjugated macromolecular composite particulate is produced by adding a monomer capable of forming the polymer (b) having the conjugated π electron and an aqueous peroxotitanic acid solution to an aqueous medium wherein the inorganic particulate (I) is dispersed and subsequently polymerizing the monomer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a conductive π-conjugated polymer composite fine particle and a method for producing the same.

  Examples of techniques for imparting electrical conductivity to the surface of an insulating base material such as plastic include electroless plating of metal, vapor deposition of metal foil, and coating of conductive paint. In electroless plating of metals, applicable substrates are often limited, and the process is complicated, and there is a problem that a large amount of harmful waste liquid containing heavy metal ions, cyanide compounds, and the like is discharged. In addition, since metal deposition is performed under vacuum, a large facility is required. On the other hand, the application of the conductive paint is very easy to construct, but a conductive component is essential in the paint.

  Conventionally, inorganic conductive pigments and metal fine particles have been used as the conductive component. Conductive pigments that are tin or antimony oxides are light or transparent, but are very expensive. Metal fine particles such as aluminum powder are relatively inexpensive, but have a problem with corrosion resistance. On the other hand, various composites of conductive polymers such as polyaniline and nonconductive inorganic fine particles have been proposed (see, for example, Patent Documents 1 to 3).

Japanese Examined Patent Publication No. 6-62887 JP-A-8-297295 JP-A-11-2441021

  The fine particles which are the above composite have low whiteness, and are obtained by adding a monomer such as aniline and a polymerization oxidizing agent such as an organic peroxide or heavy metal salt to an aqueous dispersion of inorganic fine particles and polymerizing the monomer. Since the polymerization oxidant remains in the system, it may have an adverse effect when blended with paints.

  An object of the present invention is to provide composite fine particles of a conductive polymer and non-conductive inorganic fine particles that have high whiteness and can be easily produced without any polymerization oxidant remaining in the system. .

  In solving the above-mentioned problems, the present inventors obtained composite fine particles having a relatively high whiteness by covering the surface of the inorganic fine particles with a complex of a polymer having conjugated π electrons and an inorganic oxide. In particular, by using a peroxotitanic acid aqueous solution as a polymerization oxidant, non-conductive inorganic fine particles can easily be formed between a conductive polymer and titanium oxide without the polymerization oxidant remaining in the system. The inventors have found that composite fine particles coated with the composite can be obtained, and have completed the present invention.

  That is, in the present invention, the surface of the inorganic fine particles (I) is covered with a complex (II) of a polymer (b) having a conjugated π electron and an inorganic oxide (c). A monomer capable of forming a polymer (b) having a conjugated π electron and an aqueous peroxotitanic acid solution are added to an aqueous medium in which polymer composite fine particles and inorganic fine particles (I) are dispersed, and then the monomers are polymerized. Method for producing the above-mentioned π-conjugated polymer composite fine particles produced by the method, a molded product containing the π-conjugated polymer composite fine particles, an anticorrosive containing the π-conjugated polymer composite fine particles, and the π-conjugated polymer The present invention relates to a coating agent containing composite fine particles and a coated article to which the coating agent is applied.

  According to the present invention, composite fine particles having relatively high whiteness can be obtained by coating the surface of inorganic fine particles such as titanium oxide and silicon oxide with a composite of a polymer having conjugated π electrons and an inorganic oxide. Is possible. In particular, by using a peroxotitanic acid aqueous solution as a polymerization oxidant, the polymerization oxidant remains in the system of composite fine particles in which non-conductive inorganic fine particles are coated with a composite of a conductive polymer and titanium oxide. It can be manufactured easily without any problems such as. The π-conjugated polymer composite fine particles of the present invention are useful as a conductivity imparting agent and an anticorrosion imparting agent.

  In the π-conjugated polymer composite fine particle of the present invention, the surface of the inorganic fine particle (I) is coated with a complex (II) of a polymer (b) having a conjugated π electron and an inorganic oxide (c). is there.

  Examples of the inorganic fine particles (I) include fine metal powders such as copper, iron, nickel, aluminum and zinc; fine carbon powders such as amorphous carbon, coke, graphite and non-graphitizable carbon; magnesium oxide, calcium oxide and oxidation. Inorganic oxide fine particles such as aluminum, silicon oxide, lithium silicate, titanium oxide, germanium oxide, magnesium oxide, vanadium oxide and manganese oxide; phosphates and phosphites such as lithium, sodium, potassium, magnesium, calcium and aluminum Examples thereof include inorganic phosphate fine particles. Among these, inorganic oxide (a) fine particles are particularly desirable.

  The inorganic oxide (a) is particularly preferably titanium oxide or silicon oxide. Further, from the viewpoint of the adhesion and physical stability of the polymer (b) having conjugated π electrons, it is preferably titanium oxide. Is preferred.

  The inorganic fine particles (I) preferably have an average particle diameter in the range of 30 nm to 5 μm, preferably 50 nm to 3 μm from the viewpoint of stability and conductivity.

  As the polymer (b) having a conjugated π electron, a monomer capable of forming the polymer, for example, a monomer such as acetylene, benzene, aniline, pyrrole, thiophene, furan, or a substituted derivative thereof is selected alone or in combination of two or more. A polymer or copolymer obtained by polymerization. Among these, in particular, a polymer or copolymer obtained by polymerizing at least one monomer selected from the group consisting of aniline, pyrrole, thiophene, and substituted derivatives thereof is preferable, and more preferably aniline is a monomer. From the viewpoint of stability and reactivity, a polymer or copolymer obtained by polymerization as is preferred. Examples of the substituent of the monomer include an alkyl group having 1 to 30 carbon atoms, an alkoxyl group, an alkylene oxide group, a sulfonic acid group, and an alkylene sulfonic acid group.

  The inorganic oxide (c) is not particularly limited as long as it can form a complex with the polymer (b) having the conjugated π electron, but titanium oxide is particularly preferable in terms of the production method.

  The abundance ratio of the polymer (b) having a conjugated π electron and the inorganic oxide (c) in the complex (II) is in the range of 1/99 to 99/1, preferably 30/70 to 70/30 by weight. It is desirable from the viewpoint of conductivity and uniformity of the particle size of the fine particles.

  In the composite fine particles of the present invention, the abundance ratio of the inorganic fine particles (I) and the composite (II) is in the range of 10/90 to 99/1, preferably 30/70 to 70/30, by weight. It is desirable from the viewpoints of conductivity and uniformity of fine particle diameter.

  The composite fine particles of the present invention are obtained by polymerizing monomers capable of forming a polymer (b) having conjugated π electrons on the inorganic fine particles (I), and the formed polymer (b) and the inorganic oxide (c). Any method that can be coated with a composite can be produced without any particular limitation. In particular, in the present invention, a polymer (b) having conjugated π electrons in an aqueous medium in which the inorganic fine particles (I) are dispersed. After the addition of the monomer capable of forming an aqueous solution and a peroxotitanic acid aqueous solution, the monomer is polymerized, whereby the polymer (b) having a conjugated π electron and the π-conjugated polymer composite fine particle, which is a composite of titanium oxide, are suitably obtained. Can be manufactured.

  In the present invention, the peroxotitanic acid aqueous solution is used as a polymerization oxidizing agent, and is usually metal titanium, hydrolyzable titanium compound, low condensate of hydrolyzable titanium compound, metatitanic acid, titanium hydroxide, and water. It can be obtained by mixing at least one titanium compound selected from the group consisting of low condensation products of titanium oxide with hydrogen peroxide. Among the titanium compounds, hydrolyzable titanium compounds are particularly preferable from the viewpoint of reactivity.

As the hydrolyzable titanium compound, in particular, the general formula (1)
Ti (OR) ₄ (1)
(In the formula, R is the same or different and represents an alkyl group having 1 to 5 carbon atoms). Moreover, as a low-condensate of a titanium hydroxide compound or a hydrolyzable titanium compound, a thing with a condensation degree of about 2-30 is preferable.

  In the aqueous peroxotitanic acid solution, the titanium compound and the hydrogen peroxide solution are used in an amount of 1 to 1,000 parts by weight, preferably 10 to 200 parts by weight in terms of hydrogen peroxide, with respect to the former being 100 parts by weight. Mixing in proportions is preferred. If the latter is less than 1 part by weight in terms of hydrogen peroxide, a stable and uniform aqueous solution cannot be obtained, and long-term storage becomes difficult. On the other hand, if it exceeds 1,000 parts by weight, the oxygen partial pressure becomes high and the foamability is strong. Since it becomes unstable storage, it is not preferable.

  The hydrogen peroxide concentration of the hydrogen peroxide solution is not particularly limited, but is preferably in the range of 3 to 30% by weight from the viewpoint of ease of handling.

  The mixing of the titanium compound and the hydrogen peroxide solution is usually preferably performed at about 1 to 70 ° C. with stirring for about 10 minutes to 20 hours. When mixing, for example, methanol or ethanol is used as necessary. Water-soluble organic solvents such as alcohols such as n-propanol and iso-isopropanol; alcohol ethers such as ethylene glycol monobutyl ether and propylene glycol monomethyl ether can also be used.

  In the peroxotitanic acid aqueous solution, by mixing the titanium compound with hydrogen peroxide solution, the former is hydrolyzed with water to form a hydroxyl group-containing titanium compound, and then hydrogen peroxide is immediately distributed to the hydroxyl group-containing titanium compound. It is inferred that it is obtained by forming peroxotitanic acid at the same position. This aqueous solution of peroxotitanic acid is highly stable at room temperature and can withstand long-term storage.

  The inorganic fine particles (I) to be dispersed in the aqueous medium are preferably added in the range of 1 to 40 parts by weight, preferably 5 to 20 parts by weight with respect to 100 parts by weight of the aqueous medium.

  The monomer to be added to the aqueous medium is preferably added in the range of 1 to 20 parts by weight, preferably 5 to 10 parts by weight with respect to 100 parts by weight of the aqueous medium. When the monomer is added, an inorganic acid such as sulfuric acid, hydrochloric acid, nitric acid, perchloric acid, phosphoric acid, or an organic acidic compound such as carboxylic acid or sulfonic acid may be appropriately added from the viewpoint of stability. desirable.

  The aqueous peroxotitanic acid solution is preferably added so that the amount of peroxotitanic acid is 0.1 mol or more, preferably 0.5 to 5 mol per mol of the monomer, from the viewpoint of the reactivity of the monomer. is there.

  The aqueous medium can appropriately contain an organic solvent such as alcohol or ketone, if necessary, in addition to water. In addition to the peroxotitanic acid aqueous solution, a known polymerization oxidant, for example, persulfate such as ammonium persulfate or potassium persulfate; ferric sulfate, iron trichloride, cupric chloride, etc. may be appropriately added to the aqueous medium. May be.

  The monomer polymerization reaction proceeds easily at room temperature with stirring, but it is desirable to control the polymerization to about -20 to 35 ° C, preferably -5 to 30 ° C as necessary, and the reaction time is about 1 to 10 hours. Preferably, 2 to 5 hours is appropriate.

  The π-conjugated polymer composite fine particles of the present invention are obtained in a state of being dispersed in an aqueous medium. If necessary, the π-conjugated polymer composite fine particles are separated from the aqueous medium by filtration or the like, washed, then taken out in a wet state, or dried. It can be a powder.

  The π-conjugated polymer composite fine particles of the present invention can be used as a conductive agent, an antistatic agent, and an anticorrosive agent. For example, the π-conjugated polymer composite fine particles are kneaded with a thermoplastic resin, etc. Can be processed into a molded product and used in coatings such as paints, adhesives, and processing agents by dispersing in water or organic solvents with or without other resins and additives. Can be used as

  The content of the π-conjugated polymer composite fine particles of the present invention in the molded product can be appropriately selected depending on the shape and purpose, but is usually 30 to 90% by weight, preferably 50 to 80% by weight in the molded product. It is appropriate to be within the range. The content of the π-conjugated polymer composite fine particles of the present invention in the coating agent can be appropriately selected depending on the purpose, but is usually 5 to 50% by weight, preferably 10 to 30% by weight in the solid content of the coating agent. It is appropriate to be within the range.

  Hereinafter, the present invention will be further described by examples.

Example 1
Put 213 g of 30% hydrogen peroxide and 233 g of pure water in a 2 liter flask, keep the liquid temperature at 0-5 ° C. It was dripped slowly. After completion of the addition, the mixture was stirred for about 3 hours while maintaining the liquid temperature at 0 to 5 ° C. to obtain a yellowish brown peroxotitanic acid aqueous solution (T-1).

  Next, 90 g of pure water and 10 g of titanium oxide fine particles (“Titanium oxide CR-95” manufactured by Ishihara Sangyo Co., Ltd.) are placed in a 200 cc flask, and 100 g of the peroxotitanic acid aqueous solution (T-1) is further added. The mixture was vigorously stirred while maintaining the liquid temperature at 0 to 5 ° C. Next, 5.0 g of aniline and 5.4 g of 98% sulfuric acid were added simultaneously and kept at a temperature of 20 ° C. or lower with vigorous stirring for 5 hours to obtain a dispersion containing light green fine particles. The average particle diameter of the fine particles was about 1.5 μm as measured by a dynamic light scattering method.

  The dispersion was allowed to stand to precipitate fine particles, and the supernatant was removed. The fine particles were washed with methanol and pure water and heated at 80 ° C. for several hours to obtain about 16 g of green powder. .

The obtained powder was compression molded under 20 MPa for about 10 minutes to prepare tablet pellets. Measures the conductivity of the pellets by the four-terminal method (a method of measuring the resistance value of a low-conductivity film, etc. defined in JIS K 7194, by removing the contribution of contact resistance using four terminals). As a result, it was 1.1 × 10 ⁻³ S / cm.

Example 2
In Example 1, the amount of peroxotitanic acid aqueous solution (T-1) was 233 g, the aniline amount was 3.0 g, and the 98% sulfuric acid amount was 3.2 g. A green powder was obtained. In the same manner as in Example 1, tablet pellets were prepared and the conductivity was measured. As a result, it was 4.0 × 10 ⁻⁴ S / cm.

Example 3
In Example 1, the amount of peroxotitanic acid aqueous solution (T-1) was 100 g, the amount of aniline was 7.0 g, and the amount of 98% sulfuric acid was 7.5 g. Of dark green powder. In the same manner as in Example 1, tablet pellets were prepared and the electrical conductivity was measured. As a result, it was 3.3 × 10 ⁻³ S / cm.

Example 4
In Example 1, the same amount as in Example 1 except that the amount of aqueous peroxotitanic acid (T-1) was 100 g, the amount of fine titanium oxide particles was 14 g, the amount of aniline was 3.0 g, and the 98% sulfuric acid amount was 3.2 g. In this way, about 21 g of green powder was obtained. It was 1.0 * 10 < ^-4 > S / cm when the tablet pellet was created similarly to Example 1 and the electrical conductivity was measured.

Comparative Example 1
In a flask with an internal volume of 200 cc, 147 g of pure water and 10 g of titanium oxide fine particles (“Titanium oxide CR-95” manufactured by Ishihara Sangyo Co., Ltd.) are added, and 43 g of 35% hydrogen peroxide water is further added to bring the liquid temperature to 0. Stir vigorously while maintaining ˜5 ° C. Next, 5.0 g of aniline and 5.4 g of 98% sulfuric acid were added at the same time, but they did not react and the monomer and titanium oxide fine particles were recovered.

Claims (14)

A π-conjugated polymer composite fine particle, wherein the surface of the inorganic fine particle (I) is coated with a complex (II) of a polymer (b) having a conjugated π electron and an inorganic oxide (c). The π-conjugated polymer composite fine particles according to claim 1, wherein the inorganic fine particles (I) are fine particles of an inorganic oxide (a). The π-conjugated polymer composite fine particles according to claim 2, wherein the inorganic oxide (a) is titanium oxide or silicon oxide. 2. The polymer (b) having conjugated π electrons is a polymer or copolymer obtained by polymerizing at least one monomer selected from the group consisting of aniline, pyrrole, thiophene, and substituted derivatives thereof. The π-conjugated polymer composite fine particle as described. The π-conjugated polymer composite fine particle according to claim 1, wherein the inorganic oxide (c) is titanium oxide. 2. The π-conjugated polymer composite according to claim 1, wherein the abundance ratio of the polymer (b) having a conjugated π electron and the metal oxide (c) in the composite (II) is 1/99 to 99/1 by weight. Fine particles. The π-conjugated polymer composite fine particles according to claim 1, wherein the abundance ratio of the inorganic fine particles (I) and the composites (II) is 10/90 to 99/1 by weight. A monomer capable of forming a polymer (b) having conjugated π electrons in an aqueous medium in which the π-conjugated polymer composite fine particles according to claim 1 are dispersed in inorganic fine particles (I). And a method for producing π-conjugated polymer composite fine particles produced by polymerizing the monomer after adding a peroxotitanic acid aqueous solution. The peroxotitanic acid aqueous solution is at least one titanium selected from the group consisting of metallic titanium, hydrolyzable titanium compounds, low-condensates of hydrolysable titanium compounds, metatitanic acid, titanium hydroxide, and low-condensates of titanium hydroxide. The method for producing π-conjugated polymer composite fine particles according to claim 8, wherein the compound is obtained by mixing a compound with hydrogen peroxide. The π-conjugated polymer composite fine particle according to claim 8, wherein the aqueous solution of peroxotitanic acid is added so that the amount of peroxotitanic acid is 0.1 mol or more with respect to 1 mol of the monomer capable of forming the polymer (b). Production method. A shaped product containing the π-conjugated polymer composite fine particles according to any one of claims 1 to 7. An anticorrosive containing the π-conjugated polymer composite fine particle according to any one of claims 1 to 7. A coating agent comprising the π-conjugated polymer composite fine particles according to any one of claims 1 to 7. A coated article to which the coating agent according to claim 13 is applied.