JP2005307010A - pi-CONJUGATED MACROMOLECULAR COMPOSITE MICROPARTICLE - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide composite microparticles of an electrically conductive polymer and electrically nonconductive inorganic microparticles. <P>SOLUTION: The π-conjugated macromolecular composite microparticles are characterized by consisting of a composite of a conjugated π-electron-bearing polymer and a titanium oxide, being obtained by adding a monomer(A) capable of forming the π-electron-bearing polymer to an aqueous peroxotitanic acid solution(B) followed by polymerizing the monomer(A). The aqueous peroxotitanic acid solution(B) is prepared by mixing an aqueous hydrogen peroxide solution with at least one titanium compound selected from the group consisting of metallic titanium, hydrolyzable titanium compound, its oligomeric condensate, metatitanic acid, titanium hydroxide and its oligomeric condensate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a conductive π-conjugated polymer composite fine particle.

  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 as a composite 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. In some cases, the polymerization oxidant remains on the surface, which 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 are easy to manufacture and do not leave a polymerization oxidizing agent in the system.

  In solving the above-mentioned problems, the present inventors can easily use a peroxotitanic acid aqueous solution as a polymerization oxidant, so that the conductive polymer and titanium oxide can be easily combined with the polymerization oxidant without remaining in the system. The present inventors have found that composite fine particles can be obtained and completed the present invention.

  That is, the present invention has a conjugated π electron obtained by polymerizing the monomer (A) after adding the monomer (A) capable of forming a polymer having a conjugated π electron to the peroxotitanic acid aqueous solution (B). A π-conjugated polymer composite fine particle characterized by being a composite of a polymer and titanium oxide, a molded product containing the π-conjugated polymer composite fine particle, an anticorrosive containing the π-conjugated polymer composite fine particle, The present invention relates to a coating agent containing the π-conjugated polymer composite fine particles and a coated article to which the coating agent is applied.

  According to the present invention, by using a peroxotitanic acid aqueous solution as a polymerization oxidant, composite fine particles of a conductive polymer and titanium oxide can be easily produced without any inconvenience such as a polymerization oxidant remaining in the system. can do. The π-conjugated polymer composite fine particles of the present invention are useful as a conductivity imparting agent and an anticorrosion imparting agent.

  Examples of the monomer (A) capable of forming a polymer having a conjugated π electron in the present invention include acetylene, benzene, aniline, pyrrole, thiophene, furan, and substituted derivatives thereof, and these are used alone or Two or more types can be selected and copolymerized. Among these, at least one selected from the group consisting of aniline, pyrrole, thiophene, and substituted derivatives thereof is particularly preferable, and aniline is more preferable from the viewpoint of stability and reactivity.

  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.

  In the present invention, the peroxotitanic acid aqueous solution (B) 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 at least one titanium compound selected from the group consisting of low condensation products of titanium hydroxide and mixed 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 (I)
Ti (OR) ₄ (I)
(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 peroxotitanic acid aqueous solution (B), the titanium compound and the hydrogen peroxide solution are 100 parts by weight of the former and 1 to 1,000 parts by weight in terms of hydrogen peroxide, preferably 10 to 200 parts by weight. It is preferable to mix at a weight part ratio. 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.

  The aqueous solution of peroxotitanic acid (B) is obtained by mixing the titanium compound with hydrogen peroxide solution, whereby the former is hydrolyzed with water to produce a hydroxyl group-containing titanium compound. It is assumed that is obtained by coordinating immediately to form peroxotitanic acid. This aqueous peroxotitanic acid solution (B) is highly stable at room temperature and can withstand long-term storage.

  In the present invention, after adding the monomer (A) capable of forming a polymer having the conjugated π electron to the aqueous peroxotitanic acid solution (B), the monomer (A) is polymerized to obtain a polymer having a conjugated π electron and Π-conjugated polymer composite fine particles, which are titanium oxide composites, are obtained.

  When adding monomer (A), if necessary, inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, perchloric acid and phosphoric acid, and organic acidic compounds such as carboxylic acid and sulfonic acid are used from the viewpoint of stability and reaction efficiency. It is desirable to mix appropriately.

  The monomer (A) and the peroxotitanic acid aqueous solution (B) may be added so that the amount of peroxotitanic acid is 0.1 mol or more, preferably 0.5 to 5 mol, relative to 1 mol of the monomer (A). From the viewpoint of the reactivity of the monomer (A) and the like.

  In addition to the peroxotitanic acid aqueous solution (B), a known polymerization oxidizing agent such as persulfate such as ammonium persulfate and potassium persulfate; ferric sulfate, iron trichloride, cupric chloride and the like may be added to the aqueous medium. You may add suitably.

  The polymerization reaction of the monomer (A) easily proceeds at room temperature with stirring, but is desirably controlled to about −20 to 35 ° C., preferably −5 to 30 ° C. if necessary, and the reaction time is about 1 -10 hours, preferably 2-5 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.

  In the π-conjugated polymer composite fine particles of the present invention produced as described above, the abundance ratio of the polymer having conjugated π electrons and titanium oxide is 1/99 to 99/1 by weight, preferably 30/70 to 70. / 30 is desirable from the viewpoint of conductivity, uniformity of fine particle diameter, and the like.

  The average particle diameter of the π-conjugated polymer composite fine particles of the present invention is desirably in the range of 50 nm to 2 μm, preferably 200 nm to 1 μm from the viewpoint of stability. The average particle diameter can be measured by a dynamic light scattering method.

  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 peroxytitanic acid aqueous solution (B-1).

  Next, 100 g of the above-mentioned peroxytitanic acid aqueous solution (B-1) was placed in a 200 cc internal flask, and 1.3 g of aniline and 1.4 g of 98% sulfuric acid were added simultaneously while maintaining the liquid temperature at 0 to 5 ° C. And stirred vigorously. After completion of the addition, the mixture was stirred for 5 hours while maintaining the liquid temperature at 10 to 20 ° C., and then the resulting mixture was raised to 30 ° C. to obtain a dispersion containing dark green particles. The dispersion is allowed to settle to settle the particles, and the supernatant is removed. The particles are washed with methanol and pure water, heated at 80 ° C. for several hours, and about 4.1 g of dark green composite fine particles. Of powder was obtained.

The obtained powder was compression molded under 20 MPa for about 10 minutes to prepare tablet pellets. Measures the electrical conductivity of the pellets by the four-terminal method (a method of measuring resistance values of films with low electrical conductivity, etc. defined in JIS K 7194, using four terminals to remove the contribution of contact resistance) As a result, it was 4.0 × 10 ⁻³ S / cm.

Example 2
About 6.0 g of composite fine particles were obtained in the same manner as in Example 1, except that 3.0 g of aniline and 3.3 g of 98% sulfuric acid were used. When tablet pellets were prepared in the same manner as in Example 1 and the conductivity of the pellets was measured, it was 2.0 × 10 ⁻³ S / cm.

Example 3
In the same manner as in Example 1, except that 7.0 g of aniline and 7.5 g of 98% sulfuric acid were used, about 13.7 g of composite fine particles were obtained. When tablet pellets were prepared in the same manner as in Example 1 and the conductivity of the pellets was measured, it was 1.2 × 10 ⁻³ S / cm.

Example 4
In the above Example 1, about 7.0 g of composite fine particles were prepared in the same manner as in Example 1 except that 3.0 g of pyrrole was used instead of aniline and 3.0 g of 36% hydrochloric acid was used instead of 98% sulfuric acid. Obtained. When tablet pellets were prepared in the same manner as in Example 1 and the conductivity of the pellets was measured, it was 7.5 × 10 ⁻³ S / cm.

Comparative Example 1
Into a flask with an internal volume of 200 cc, 43 g of 30% hydrogen peroxide water and 57 g of pure water were added, and 1.3 g of aniline and 1.4 g of 98% sulfuric acid were added simultaneously while keeping the liquid temperature at 0 to 5 ° C. Stir vigorously. After completion of the addition, the aniline polymer could not be obtained by heating and stirring, and the aniline monomer and brown by-product were recovered.

Claims (9)

A polymer having a conjugated π electron and a titanium oxide obtained by polymerizing the monomer (A) after adding the monomer (A) capable of forming a polymer having a conjugated π electron to the peroxotitanic acid aqueous solution (B) A π-conjugated polymer composite fine particle characterized by being a composite. The π-conjugated polymer composite according to claim 1, wherein the monomer (A) capable of forming a polymer having a conjugated π electron is at least one selected from the group consisting of aniline, pyrrole, thiophene, and substituted derivatives thereof. Fine particles. The peroxotitanic acid aqueous solution (B) is at least one selected from the group consisting of metal titanium, hydrolyzable titanium compounds, hydrolyzable titanium compound low condensates, metatitanic acid, titanium hydroxide and titanium hydroxide low condensates. The π-conjugated polymer composite fine particles according to claim 1, which are obtained by mixing a seed titanium compound with aqueous hydrogen peroxide. The π-conjugated polymer composite according to claim 1, wherein the monomer (A) and the peroxotitanic acid aqueous solution (B) are added so that the amount of peroxotitanic acid is 0.1 mol or more with respect to 1 mol of the monomer (A). Fine particles. The π-conjugated polymer composite fine particle according to claim 1, wherein the abundance ratio of the polymer having conjugated π electrons and titanium oxide in the composite fine particle is 1/99 to 99/1 by weight ratio. A molded body containing the π-conjugated polymer composite fine particles according to any one of claims 1 to 5. An anticorrosive containing the π-conjugated polymer composite fine particles according to any one of claims 1 to 5. A coating agent comprising the π-conjugated polymer composite fine particles according to any one of claims 1 to 5. A coated article to which the coating agent according to claim 8 is applied.